Compilation of Larry Gibson’s load tests

**Silvercreek Farmer** · 12-25-2022, 06:02 PM

Not a discussion thread! Please follow the provided links if you would like to discuss the topic!

With Larry’s permission, I’m starting a thread to compile his posts containing load testing information. Larry has posted a lot of great data over the years, and hopefully the mods will find it sticky worthy. Feel free to help with this project. Please copy and paste the post as well as a link to the original thread. Thank you.

**Silvercreek Farmer** · 12-25-2022, 06:03 PM

https://castboolits.gunloads.com/sho...llets-amp-2400

Please note; I am not recommending or saying anyone should shoot any of these loads in any revolver/firearm other than a 357 Magnum chambered revolver/firearm. I certainly do not recommend them for use in any 38 SPL chambered revolver other than the S&W 38/44 “Outdoorsman”, the Colt New Service and the Ruger Security Six chambered in 38 SPL. Even then I would only recommend loads within 38 SPL +P pressures. The data presented here is for information only.

38 SPL +P+ or 38/44 Loads with 170 gr Cast Bullets & 2400

Often on the forum someone asks about loading 160 – 180 gr cast bullets over 2400 powder in the 38 SPL for use in S&W 38/40 N frames along with 357 chambered handgun/rifles. The questions usually center around start and max loads.

Rem-UMC produced a 38/44 cartridge for use in the S&W 38/44 Outdoorsman revolver, the precursor to the 357 magnum revolver. The velocity was listed with 150 and 158 gr j and lead bullets in the 1120 - almost 1200 fps (just going from memory there. Colt is said to have said the 38/44 loads were fine to use in the Colt New Service revolver.

Over the years I've seen the 358156 seated to second crimp groove over 12.0 gr 2400 as "the" load for use in the S&W 38/44 revolvers. That load was also oft recommended for use in M19s and other 357 magnum revolvers "back in the day" when 38 SPL cases were plentiful and easy to obtain and 357 magnum cases were hard to find and expensive.

The 358136/12 gr 2400 was and still is an excellent load in 357 Revolvers. Years back i shot a lot of that load in my Colt Trooper, S&W M28 and Ruger BHs. Back then, as a low paid LEO, I had lots of 38 SPL cases but little 357 Magnum cases. These days I have a sufficient quantity of 357 magnum brass to use.
I have a bit of pressure test data on the Lyman 358156 seated out to the 2nd crimp groove loaded over 2400 in 38 SPL cases for use in 3844 or 357 handguns as that is what that bullet was designed for. The 358156 has become my favorite bullet of choice in the 357 Magnum for use with top end magnum loads. Also, if I was loading +P+ 38 SPLs for use in 357 magnums that is the bullet I would use.

Some seem to want to use the heavier bullets though so I’ve pressure tested two different bullets [36-168K & 36-175H supplied by Ed Harris (Outpost75)]. Many like the 358429 or similar bullets loaded to the crimp groove in 38 SPL cases because of fit in certain Magnum cylinders and feeds in some lever guns. Many also like the longer "Keith" design SWC for longer range shooting among other reasons. I am not averse to anyone using this bullet. The above test was done because many have asked me if I have Pressure tested the 358429 or similar bullet in 38 SPL cases with 2400 powder. The above test results are in answer to those queries.

Unfortunately, I no longer had a 170 gr Lyman “Keith” 358421 mould when I started pressure testing. I never developed an affinity for that bullet in the 357 or 38 SPL so long ago when I traded off an OM Ruger BH I let the mould go with it. I regret letting the Ruger go but not the 358421 mould. With the receipt of the 36-168K (169 gr) & 36-175H (184 gr) bullets I loaded them in 10 shot test strings of 8 – 12 gr in 1 gr increments. I used W-W 38 SPL cases and WSP

primers. Alliant 2400 was used. All charges were thrown using a Lyman 55 powder thrower. The bullets were crimped in the crimp groove with moderate crimp.

Testing was done last Monday, May 22, at the local range here. Temperature was 90 degrees with 7% humidity. Testing was done in the shade so the ambient temperature is also the temperature of the ammunition.

The test firearm was a Contender with a 7.94” barrel. The pressure data and velocity was obtained via a strain gauge attached over the chamber connected to the Oehler M43 PBL. The M43 corrects the screen velocity to muzzle velocity and I posted muzzle velocity. Chronographing the similar loads in a 6” barreled Ruger Security Six results in 150 – 200 fps less velocity out of the revolver.

Test results are the averages of the 10 shots with each test string;

36-168K (169 gr)
Load……Vel……..PSI
8.0……..923……20,100
9.0…….1065…..22,800
10.0…..1151…..24,600
11.0…..1291…..27,000
12.0…..1392…..28,900

36-175H (184 gr)
Load……Vel……..PSI
8.0……..948……22,500
9.0…….1094…..24,400
10.0.....1185…..25,500
11.0…..1298…...28,100
12.0…..1396……29,700

**Silvercreek Farmer** · 12-25-2022, 06:08 PM

https://castboolits.gunloads.com/sho...n-38-SPL-Cases

Skeeter’s 357 magnum load 358156 w/2400 in 38 SPL Cases

There has been a recent thread and numerous other discussion of Skeeter Skelton’s 357 magnum level load in 38 SPL cases using the 358156 cast bullet seated to the 2nd crimp groove and loaded with 2400 powder. Skeeter loaded these for use in 357 Magnum revolvers back in the ‘60s and used and recommended them through the ‘70s when 357 Magnum cases were hard to come by except from factory ammunition. There was a plethora of 38 SPL cases available as it was the predominant LE cartridge in use throughout the country. The 38 SPL case was readily available to the general public for little cost if any.

Skeeter used the 358156 seated out to its 2nd crimp groove as that was what it was designed for. While seating the 358156 out to the 2nd crimp groove increased the case capacity in the 38 SPL case doing so still did/does not give the 38 SPL the same capacity as with the same bullet seated in the 357 Magnum case to the 1st crimp groove. I started loading for the 38 SPL and 357 Magnum. Skeeter’s load recommendation was to use 13.5 gr of Hercules 2400 but I found using 12.5 gr was a very good load in my Ruger Blackhawk and Colt Trooper. I got my first Oehler chronograph back in the early ‘70s and found the 12.5 gr load of 2400 under the 358156 seated to the 2nd crimp gr in 38 SPL cases often equaled many 357 Magnum velocities out of those revolvers.

There is a lot of discussion and consternation as to whether it is “safe” to use such a load in S&W N frame 38/44 Outdoorsman revolvers and 357 magnum revolvers. I recently conducted a pressure test of the 38 SPL case loaded with a 358156 seated to the 2nd crimp groove loaded over Alliant 2400 to give some guidance for each to make their own decision as to the “safety” of such and whether to use such. I also, just prior to the beginning of that test pressure tested five factory 38 SPL loads and my own standard load with the 358156 over 2400 in 357 magnum cases as a “reference" ammunition.

The picture shows the Contender 357 barrel of 7.94” length with a strain gauge attached and connected to an Oehler M43 PB used for pressure testing. A Ruger Security Six with 6” barrel was used to chronograph my old load previously mentioned. Also shown are the factory rounds tested as a “reference” along with the 38 SPL case with the 358156 seated to the 1st crimp groove, a 38 SPL case with the 358156 seated to the 2nd crimp groove, a 357 Magnum case with the 358156 seated to the 1st crimp groove and a 358156 cast bullet as used.

Attachment 274839

There are several things we should remember and understand. The first is the SAAMI MAP for the 38 SPL is 17,000 psi, the MPLM is 17,500 psi and the MPSM is 18,300 psi. The SAAMI MAP for the 38 SPL +P is 20,000 psi, the MPLM is 20,600 psi and the MPSM is 21,500 psi. The SAAMI MAP for the 357 magnum is 35,000 psi, the MPLM is 36,100 psi and the MPSM is 37800 psi. While ammunition manufacturers and current load manuals strive to keep the pressure under the MAP for those cartridges under some circumstance the MPLM and MPSM are still acceptable pressures.

Another thing we must understand and remember is neither pressure measurements or velocity measurements are absolute. Even with the same ammunition tested in the same firearm we find both velocity average and psi average for a test of sufficient sample can vary, sometimes significantly. If we chronograph the same load or, in my case also pressure test the same load, especially at different times under some different conditions we will find there is a +/- range. As long as the test average result falls within that +/- range of either velocity or pressure we can assume all is well. That is how the technicians in the labs do it. It’s also why we don’t see a lot of actual pressure figures for many loads and/or factory ammunition. There is a pretty wide range of not only velocity but also pressure that is acceptable by SAAMI standards.

Thus, the results of different test I post here and elsewhere may not always agree precisely with any other similar test results posted. Additionally, I’ve come to understand that when comparing similar weight cast bullets in any handgun cartridge the seating depth (not to be confused with the OAL) and the bearing surface have more affect on pressure than any small difference in weight. Note in the picture of the two 38 SPL cartridges on the left how the bullet seated to the 2nd crimp groove increases the case capacity. Note also the longer length of the Magnum case even with the bullet seated to the 1st crimp groove still has a larger case capacity.

Attachment 274840

The 358156 bullets were cast of COWWs + 2% tin, AC’d with a BHN of 12 – 14 after 14 days. The bullets were sized .358 in a Lyman 450 with Hornady GCs crimped on during sizing/lubing with BAC. The bullets weighed 162 gr fully dressed.

All tests were 10 shots of each load as per SAAMI Standards.

Ambient temperature during the tests ran 52 – 60 degrees. Humidity ran 35% with a barometric pressure hovering around 29.75.

I’ll list the load, the muzzle velocity, the velocity SD/SD [in fps], the pressure, the SD/ES {in psi]

The test of the five factory loads;

Speer 158 lead SWC 38 SPL….874 fps….15/43…..15,500 psi….900/2,400

Remington 158 LRN 38 SPL….899 fps….11/34….15,300 psi…..900/3,000

Remington 125 JHP +P….1149…..28/91….15,200 psi…..700/2,200

Remington 148 HBWC 6138….818 fps….19/63….15,000 psi….1,700/5,800

Remington 148 HBWC R38S3….805 fps….9/23….13,900 psi....600/1700

All the above velocity and pressure test results are consistent [+/-] with previous tests of the same ammunition in the same test barrel.

The test of my standard 357 Magnum load with the 358156, seated to the 1st crimp groove [OAL; 1.597”], using 14.0 gr Alliant 2400 in Winchester 357 magnum cases with CCI 500 primers;

357 Magnum SL….1548 fps….20/75….34,600 psi…..1,800/6,000

Test results of Alliant 2400 from 11.0 to 13.5 gr in ½ gr increments of Alliant 2400 in Winchester 38 SPL cases with the 358156 seated to the 2nd crimp groove [OAL; 1.517”] with CCI 500 primers.

11.0 gr 2400….1275 fps….23/72….24,900 psi….1,400/4,400

11.5 gr 2400….1349 fps…..20/69….28,700 psi….1,500/5,100

12.0 gr 2400….1358 fps….21/69….28,800 psi….800/2,500

12.5 gr 2400….1445 fps….24/73….33,200 psi….200/600

13.0 gr 2400….1486 fps….19/56….35,000 psi….2,500/7,3000

13.5 gr 2400….1531 fps….24/89….37,900 psi….2,100/7,100

Chronograph test (same Oehler M43 PBL) of the 12.5 gr load of 2400 in the 38 SPL cases with the 358156 seated to the 2nd crimp groove in the Ruger Security Six. Average is of 10 rounds in the test.

12.5 gr 2400….1251 fps…..23 fps SD….58 fps ES

Note in the pressure test this load proved to be the most uniform. The velocity loss between the 7.94” Contender solid barrel and the 6” barrel of the Ruger was 175 fps. Giving 1250 fps at 33,200 psi definitely ranks the load right “in there” with most 357 Magnum factory rounds using 150 – 158 gr bullets. I was shooting with the barrel at the ejector rod housing resting on sandbags aiming at 6 o’clock on a 50 yard pistol bullseye. All 10 test shots went into the 10 ring. That’s about as good as I can do anymore. That load was an excellent one many years ago when I was using it and it obviously is today.

As to Skeeter’s load of 13.5 gr, that load is over the SAAMI MAP for the 357 magnum cartridge but still within the MPLM and MPSM. Ballistically it is very close to my standard 357 magnum load of 14 gr but does give higher pressure. That, again is due to the lesser case capacity of the 38 SPL case even with the 358156 seated out to the 2nd crimp groove.

**Silvercreek Farmer** · 12-25-2022, 06:11 PM

https://castboolits.gunloads.com/sho...owder-Pressure

My own pressure tests (Oehler M43) in a 24" test barrel show;

415 gr Desperado 20-1 bullet
70 gr GOEX CTG
Starline cases
Fed 215M primers
19,100 psi
1233 fps

415 gr Desperado 20-1 bullet
Duplex; 7 gr 4759/ 54 gr GOEX CTG
Starline cases
Fed 215M primers
20,300 psi
1263 fps

**Silvercreek Farmer** · 12-25-2022, 06:13 PM

https://castboolits.gunloads.com/sho...Manual-Error-B

Loading Manual Error……

Over the years, especially the last nine years with an Oehler M43 actually pressure testing, I’ve discovered error in data in almost every make (Speer, Lyman, Hornady, Hodgdon and Nosler) of loading manuals. This is especially the case with data from older and newer manuals that list pressures derived from the C.U.P. method of testing. Lee’s manual simply copies the data from other sources, both C.U.P. data and modern psi data obtained from transducer/strain gauge pressure measurement. Many newer manuals have loads “adjusted”, usually down, from the data in older manuals. Many think this is from lawyers, etc. but the truth is most newer reloading manual data is derived from better and more complete pressure testing through the use of peizo-transducers and strain gauge measurements. What is found is many older loads that were thought to be within safe standards for the cartridge actually were too high in pressure.

A recent example has been found using H4350 in the 30-06 with Hornady’s new 178 gr ELD-X bullet. A friend of mine recently had goodsteel build him a long range rifle based on a M700 action. It has a 31” Palma contoured barrel with a 12” twist chambered in 30-06 XCB. Based on my previous experience with ’06 match rifles and long range rifles I suggested 4350 powder. He collected a good amount of all three flavors; IMR, Hodgdon and Accurate Arms. He also got a supple of 175 Sierra MKs and the new Hodgdon 178 ELD-X bullets. He is using Winchester match prepped cases and Federal 215 Match primers.

He decided to try the Hodgdon’s H4350 powder and turned to the Hodgdon #27 manual. One would assume Hodgdon had the data well tested and correct since it’s their powder. We were discussing the loads by phone (he is in NE Oregon and I’m in Arizona) so I opened up my Hodgdon #27 manual and turned to the data for the 30-06 with 180 gr bullets. The #27 manual lists the max load for 180 gr bullets using H4350 at 57.5 gr. That is with a C.U.P. of 49,200. The velocity listed from a 24” Winchester M70 barrel with a 10” twist at 2798 fps. I have not used H4350 in the 30-06 (I mostly use IMR and AA) so I took the data at face value.

My friend decided to work up from 54 gr in ½ gr increments to 57.5 gr of H4350. A few days later he called back just tickled pink as the 57.5 gr load was shooting right at ½ moa at 300 yards. He had broke down and bought the top end Chrony with printer but hadn’t yet chronographed it. I was up there a few weeks back on my way to the Tacoma area. We went out to the local range and set up the Chrony and chronographed the 57.5 gr load. There was no indication of excessive pressure; bolt opened normally, primers looked fine and no excessive expansion at the case head. But holy smokes…..the average velocity was 3060 fps!!!!! My prediction with either AA4350 or IMR4350 under a 175 gr Sierra MK was 2950 fps +/- given the 31” barrel……but 3060 fps? About 3 weeks later I returned back through there so we took the rifle up to another friend’s ranch where they have a 1000 yard range with a sturdy bench to shoot from. He put 9 shots consecutively into right at 1 moa at 1000 yards in a 5 -8 gusting to 10 mph side wind. I put 10 shots into 1.2 moa. Again, even though it was 80+ degrees there was no sign of excess pressure.

However, that night my friend was depriming the cases and three primers basically fell out of the pockets. The primer pockets were swollen and no longer would hold a primer. That was the first sign of excessive pressure. My friend gave me a pound of the H4350 and a box of the 178 ELD-Xs to bring home with me to pressure test that load. I have the Winchester cases and Federal 215 Match primers. When I got home I loaded test loads of 56.5, 57 and 57.5 gr. Yesterday morning at daylight I was at the range here in Lake Havasu to test those loads. Was 65 degrees so heat would not be a factor. My 30-06 test rifle is a M98 Mauser with a 24” barrel. I chambered it with a match reamer to minimal headspace. I gives pressure readings via the Oehler M43 that are commensurate with the known pressure of Federal and Winchester factory loads used as “reference ammunition”.

I shot a ten shot test with M72 Match to validate everything was set up correctly. The measured data was within normal range. I lightly cleaned the barrel and proceeded to test the 56.5 gr load. The test rounds were loaded in fire formed test Winchester cases NS’d with a Bonanza Bench rest NS die. Primers were Federal 215 Match. Powder charges were weighed with a Redding scale. The 178 ELD-Xs were seated to 3.330” which is just off the leade.

The Oehler M43 was set up to measure the pressure and velocity for each shot. Start screen was at 15 feet with a 4 foot screen spacing. Target was at 100 yards.

The 1st test shot went 2882 fps with 69,200 psi(M43)
The 2nd test shot went 2873 fps with 68,900 psi(M43)
The 3rd test shot went 2869 fps with 69,200 psi(M43)

I quit testing and did not fire the remaining 7 rounds of that load nor did I fire any of the heavier 57 and 57.5 gr loads. With the 69,000 psi +/- from the “start” load I sure wasn’t going any higher…….

Average for the 3 test shots was:
Velocity; 2875
PSI; 69,100

The M43 correction to muzzle velocity was 2884 fps. The 3 shots grouped .94”.

The 56.5 gr H4350 test load was 86 fps faster than the Hodgdon manual listed max load of 57.5 gr. Note the test barrels were both 24”. Obviously the psi of the 56.5 load was quite excessive. I hesitated to guess at the pressure of the 57.5 gr load but based on experience I’d guess it was 75,000 +/- psi….well into “proof level” loads.

On the return home I figured something was definitely amiss. I pulled the bullets of the cartridges not fired and reweighed the charges….they were spot on. I then looked at a couple burn rate charts and discovered my own “error”. H4350 is sandwiched right between AA4350 and IMR4350. My experience with both of those is that 56 gr is a max load (measured 60 – 62,000 psi) under a 180 gr Hornady SPBT. I then checked Hornady’s 8th and 10th Edition manuals. They list 55.3 gr H4350 as a max load under 178 – 180 gr bullets…….Hello......says I, there’s a 2.2 gr difference between the Hodgdon and Hornady manuals. The 2700 fps velocity level +/- is also commensurate with what I get out of my test rifle and M70 (24” barrels with 56 gr AA4350.

Examination of the fired cases revealed no sign of excessive pressure as shown here. They were fired left to right. The primers appear normal for a top end jacketed 30-06 load with 60,000 psi. 2nd photo shows the case as fired left to right with a fire formed case (far right) from a previous normal psi firing.

Again, no sign of excessive pressure, just normal expansion at the expansion ring after 3 firings.

Attachment 204826Attachment 204827

I’ve reloaded up test strings of 54.5, 55.0 ,55.3, 55.6 and 55.9 H4350 with all other load parameters being the same. Hoping to test before the week is out. I will post the results here.

Today September 28, 2017 I completed the test. I again set up at daylight with little to no wind and the temp right at 70 degrees. Results are;

54.5 gr; 2743 fps with 56,600 psi(M43)
55.0 gr: 2801 fps with 60,400 psi(M43)
53.3 gr; 2833 fps with 61,900 psi(M43)
55.6 gr; 2850 fps with 63,700 psi(M43)

I did not test the 55.9 gr load.

The maximum load listed in Hornady 8th and 10th editions is correct at 55.3. Any modern action also chambered in .308W ill also handle this psi level. I would consider the 54.5 gr load as maximum in older actions such as the M1903s.

The Hodgdon maximum load is 2.2 gr higher and obviously is too much.

This obvious error in older loading data with the pressure measured via the C.U.P. method is another example that care should be exercised when using older data, especially when the pressure is listed as measured with the C.U.P. method. New comers to reloading should head advice not to jump to the top load of a manual or to use loads given on internet sites and forums without consulting other references. Even then a reduction and proper work up should always be done.

A chronograph also is an excellent tool to use when developing loads, especially if one is going to approach top end jacketed loads. When the velocity is faster than the published data understand there is probably only one reason why; pressure.

Larry Gibson

**Silvercreek Farmer** · 12-25-2022, 11:25 PM

https://castboolits.gunloads.com/sho...use-of-fillers

I have for many, many years found dacron (polyester fill) to be the best "filler". I use a filler only when appropriate. Many think I always use a filler with every powder....I DO NOT!!!! The use of the filler can cause problems if not used correctly and when appropriate. If the powder is not correct for the bullet/cartridge combination then the filler is not going to make it "right". Many want to use a specific powder for a cartridge because the powder is "cheap" or because "they have a lot of it". There are lots of powders that are not only poor choices to use but that can be dangerous if used in an inappropriate bullet/cartridge combination. Do yourself a favor if you are wanting to use an inappropriate powder (usually "no data" available is an indication the powder might be inappropriate) and get an appropriate powder. You will save yourself a lot of frustration. The use of the dacron filler only makes an appropriate powder perform better. The dacron filler will not make a silk purse out of a sow's ear.

I don't use the dacron filler or a wad with the fast to medium burning "fast" pistol /shotgun type powders. I find one of these fast burning powders that is fast enough to ignite and burn efficiently at the velocity I want and avoid using a filler with them.

I almost always use the dacron filler in rifle cases with the slower “fast” burning powders (4227, 4759, 5744, 4198, etc. with lighter medium weight bullets for the cartridge; i.e. 140 - 165 gr bullets in .30/.31 cals of 30-30 through '06 case capacity), the medium burning powders (RL7, 3031, 4895, etc.) up through the slow burning powders (RL19, AA4350, H4831SC, RL22, 3100, etc.) that give around 80% or less loading density under medium to heavy weight bullets for the cartridge; i.e. 170 - 220+ gr bullets in .30/.31 cals. Those examples are for the .30/.31 cals but the same guidance applies to other calibers. The dacron filler is used only between the powder and base of the bullet.

The “dacron” is polyester fill as commonly found in pillows and toys. It also comes in sheets called “batting”. It can be obtained very reasonably at most any fabric store.

The dacron batting comes in various thicknesses. I prefer that which is about 5/8" thick. My wife recently bought me 10 yards which will give many, many thousands of cast bullet loads. With this current batch of batting I cut it initially across the width into strips about 3/4" wide. I then "eyeball" cut 1/2" wide chunks which is close to 3/4 gr.

A smaller chunk is cut for 1/2 gr and larger for a larger amount. I've cut some chunks that weight 1/2, 3/4, 1, 1 1/4 and 1 1/2 grs and have them in a "snack" baggie stuck on a poster board above my loading bench for quick reference when I need to cut new chunks. The batting will run thin and thick throughout the sheet so I again just "eyeball it" based on the thickness of the batting when cutting the chunks.

Pretty extensive tests have demonstrated that the weight of the filler does not have to be exact, only close. What is important is that there is enough so that it “fills" the space between powder and bullet. A little too much hurts nothing but too little poses problems. That's why I have the different size "chunks" so I can use the right size for the case capacity I am filling. For example; with most medium burning powders (3031, 4895, 4064) in and '06 to function an M1 a 3/4 gr dacron filler is about right. With slower powders that give a higher loading density like 4831 a 1/2 gr filler is about right.

I use a section of .22 cal cleaning rod in cartridges of .30 - .375 cal to push the Dacron chunk inside the case just so it is all in. The 6 to 10" section gives plenty to hold onto and sufficient "feel". Merely hold the chunk of dacron over the case mouth and shove it in with the rod. Sometimes it takes a couple three pokes to ensure all is inside the case mouth. I poke the chunks in until all the dacron is at the bottom of the neck or at least all in the case. It doesn’t matter exactly where just so long as you don’t tamp it down on the powder as a wad and leaved a space between the base of the bullet and the dacron.

What you want to do is push it in to let the base of the bullet finish pushing it down and adding any compression against the powder. Thus I do not push it down on the powder but let the bullet do that when the bullet is seated. Using the right size chunk of dacron this method then provides a "filler" in the air space between the powder and base of the bullet.

A small length of coat hanger works for the .22-7mm cartridges and an unsharpened pencil works well for .45 cals. With the charged cases in a loading block I simply hold the chunk of dacron over the case mouth and push it in with the rod. It is quite easy and a lot of “precision is not required, just get the dacron into the case and let the bullet finish pushing it down.

Larry Gibson

**Silvercreek Farmer** · 12-25-2022, 11:30 PM

https://castboolits.gunloads.com/sho...x39-Cast-loads

During the latest thread on LeveRevolution Powder Junior1942 PM’d me asking about the 30-30 testing I had done with the RCBS 30-180-FN and that powder.He asked about the test and was trying to correlate the psi’s from that test to the 7.62x39 for possible use in his YugoSKS.He primarily was interested to see if the LeveRevolution powder would give him a bit better performance under his COWW cast bullets which weight 197 gr.Isuggested there was no sense trying to correlate when I could pressure test in the 7.62x39 also.I suggested he send some bullets and the data for his other powder loads and I would pressure test those also.Junior thought that was agreat idea.He asked how many bullets?I told him a hundred minimum.

Junior scrounged around and found about a hundred (104 to be exact) he had already cast and said he’d cast up some more and send ’em if need be.He said a few were wrinkled.Told him they’d be fine for the initial LeveRevolution work up as we were interested there was the psi. I got the bullets a couple days later.They were sized at .314, had Hornady GCs and were lubed with LLA.The BHN measured 11 – 12.I proceeded to check out the Mini Mk X Mauser I would use for the test.Unfortunately the strain gauge had partially cracked for some reason.It hadn’t been used in over 2 years and the change in location, temperatures and humidity are my guess why.Called the company to order some more gauges and they would take about 6 – 7 weeks.Told Junior and he was a bit down over that.However, in about 2 weeks a package showed upwith the strain gauges.

IPM’d Junior and told him I was ready to test and asked a couple clarification questions about his standard loads.I didn’t hear back from Junior and just assumed he was away or busy.I did not know he had gone to the big range.I proceeded with the test and will post the results here…..for Junior…..rest in peace, may the sun always be to your back, the wind in your face and all your shots fly true.

Test rifle; Interarms Mini Mk X
Caliber; 7.63x39
Bore; .301
Groove; .311
Barrel length/twist; 20”/1-9.5”
Sights; Bushnell 4X scope

Testequipment; Oehler M43 PBL

Range; Sara Park, Lake Havasu City, AZ

Test range; 100 yards, solid cement benches

Rest; Hoppe’s front and leather sand bag (rabbit ear) rear

Test shots; due to limited number of bullets not all test strings had 10 shots. Some had less but not less than 7 shots.The LeveRevolution psi workup had 2 shots per powder charge.

Attachment 112982

The test was conducted on two separate days early in the mornings. This gave the least heat (this is the desert with day time temps running 105 – 115) at daybreak (85 – 90) and the least wind. Juniors standard loads and the LeveRevolution psi work up was conducted on the 1st day along with a LeveRevolution psi workup with a 175 gr C314041 cast bullet of my own. The second day was the test of 3 loads of the LeveRevolution under Juniors 30-180-FNs and 3 loads under my own C314041.

The 1st day’s tests;

Reference ammunition test; The CIP Pmap (Maximum Average Pressure) for the 7.62x39 cartridge is 51,500 psi (peizo-transducer or strain gauge. Three factory loads were tested to set a base line for the mini Mk X.

Attachment 112983

**Silvercreek Farmer** · 12-25-2022, 11:31 PM

https://castboolits.gunloads.com/sho...LeveRevolution

In conjunction with a recent test of Junior1942s favoriteloads for his SKS using the RCBS 30-180-FN (197 gr cast of COWWs) I also tested the 7.62x39 cartridge with theGB C314-041 bullet with LeveRevolution powder.If you read the thread on Junior’s loas you saw that LeveRevolutionpowder under the heavier 197 gr RCBS bullet worked quite well in the 7.62x39cartridge.The RPM Threshold with COWWcast bullets was pushed up 150 + fps while maintaining quite less psi than withthe more popular medium burning powders such as 4895 and Varget.

Referring back to the 30-30 test I conducted withLeveRevolution powder it was found there a bullet of 170 + gr was really neededto get the LeveRevolution powder to burn efficiently.My testing of this powder with cast bulletsso far has consistently shown that LeveRevolution powder requires 26 – 28,000psi to begin burning efficiently.Withthe 30-180-FN seated to max magazine length for the SKS 27.5 gr gave about 105%load density and produced 28,700 psi(M43) under the RCBS 197 gr bullet and gavevery good accuracy at 1843 fps out of the test rifles 20” barrel.

The question was; would the 175 gr (COWWs + 2% tin at 13 –15 BHN) GB C314-041 provide enough mass for LeveRevolution to burn efficiently?With the bullet seated so the cartridge OALwas 2.206” the load density of LeveRevolution powder at 100% was 29.5 gr in theFL sized Winchester cases.I ran an initialpressure/velocity work up from 26.5 gr to 29.5 gr.That showed the 29.5 gr load might be 25,000psi at around 1900+ fps.I loaded 10shot test strings of 27.5, 28.5 and 29.5 gr to test.

Results;

Testrifle; Interarms Mini Mk X
Caliber;7.63x39
Bore;.301
Groove;.311
Barrellength/twist; 20”/1-9.5”
Sights;Bushnell 4X scope

Testequipment; Oehler M43 PBL

Range;Sara Park, Lake Havasu City, AZ

Testrange; 100 yards, solid cement benches

[FONT="Times New Roman"][SIZE=3][COLOR=#000000][FONT=Calibri]Rest;Hoppe’s front and leather sand bag (rabbit ear) rear

Attachment 150923

Bullet; Lee Group buy 6 cavity C314-041

GCs; mine out of .014 brass shim stock

Lube; NRA 50/50

Sized to; .312

Alloy; COWWs + 2%tin AC’d BHN 13 – 15

Cases; Winchester, FL sized

Primers; CCI 200

Cartridge OAL ; 2.206” with GCs at the bottom of the caseneck with light crimp under driving band.

The 27.5 gr load; we see this load did not burnefficiently at all. The cases were sooty clear back the case head and aroundthe rims.The large ES of velocity andgroup size of 5.5’ says it all.I tracethrough the target bullet holes onto the data sheet for a record of the group.

Velocity; 1781 fps

Psi(M43); 22,000

Accuracy; 5.5”
[FONT=Times New Roman][SIZE=3][COLOR=#000000]

Attachment 150927

28.5 gr; Accuracy got better and the ES was about half ofthe previous load.This indicates thepowder is starting to burn more efficiently except there still was soot abouthalf way back along the cases indicating the pressure curve was not sufficientfor the case to obdurate and seal the chamber.

Velocity;1884 fps

Psi(M43);23,900

Accuracy;3.6”
[FONT=Times New Roman][SIZE=3][COLOR=#000000]

Attachment 150928

29.5 gr; things are beginning to come together.The psi is still a bit low as we see a coupleof the shots fell out the bottom psi wise.The velocity ES is very good and the accuracy given the velocity is alsoquite good.Still some sooting of thenecks and shoulder area on the cases indicating obturation of the case is stilla problem.The average psi is stillbelow where LeveRevolution really burns efficiently.

Velocity;1944 fps

Psi(M43);24,800

Accuracy;2.5”
[FONT=Times New Roman][SIZE=3][COLOR=#000000]

Attachment 150929

Perhaps in the test rifle which is a bolt action necksized fire formed cases will allow 30 gr or maybe 30.5 gr of LeveRevolutionpowder with this 175 gr bullet in the small 7.62x39 case.If so then the psi may get high enough forefficient powder burning.However, forthose who might want to use this powder in the SKS or AK I suggest a heavierbullet of 180 at least and perhaps 185 gr or use the RCBS 30-180-FN which seemsto cast on the heavier side.

Larry Gibson

**Silvercreek Farmer** · 12-25-2022, 11:37 PM

https://castboolits.gunloads.com/sho...ckets-to-Boxer

Converting Berdan Primer Pockets to Boxer

Several pics with this one, probably best to follow the link vs reposting.

**Silvercreek Farmer** · 12-25-2022, 11:44 PM

https://castboolits.gunloads.com/sho...les-vs-Alliant

2400; Hercules vs Alliant

Sometime back I stated I would conduct a pressure test comparing the old Hercules 2400 with the newer Alliant 2400. Alliant, since taking over manufacture of the Hercules powders, says they have not changed the formula of 2400 yet most reloading manuals show a decline of around 1 gr with maximum loads. The question of whether or not there is a difference between old Hercules 2400 and Alliant 2400 most often comes up with the .44 magnum, specifically with 429421 and the classic “Keith” load of 22 gr under that bullet. Lyman’s Cast Bullet Manual lists a maximum load at 23.4 gr of 2400 with the 429421 cast bullet, their “Keith” bullet. Some say 21 grains is the max with the newer Alliant 2400 and others still shoot 22 gr of the newer Alliant 2400 the same as they did with Hercules 2400. This begs the question; is there a difference between the older Hercules 2400 and the newer Alliant 2400? This test will focus on the pressure difference between the two powders if any. Though I will mention accuracy in a couple places let us remember we are concerned about pressure here and what is a “safe” load, not what is an accurate load.

As an after thought I also decided to throw in a test string using magnum large pistol primers to test whether there is an internal ballistic difference between their use and the normal use of a standard large pistol primer in the 44 magnum with the classic “Keith” load.

I have conducted this because I have the equipment not only to measure the velocity but also the psi of many cartridges, the 44 magnum included. I also decided to include a test of a popular load using 2400 with a 160 grain cast bullet in the 30-30.

I conducted the test yesterday, the 7th of January 2010. The test was conducted at Tacoma Rifle and Revolver Club on the main range. There are very solid cement benches there and I use the same bench when conducting pressure tests with the screens, equipment set up in the same position and locations. The test instrument is the M43 Personal Ballistics Laboratory made by Oehler Research. The test firearm was the Thompson Center Contender; a 8.4” barrel for the .44 magnum and a 21” barrel for the 30-30. The 44 magnum barrel has a 1.5X Bushnell scope mounted on it and the 30-30 barrel has a Weaver K4. The 30-30 barrel is in carbine form with a Brown thumbhole rear stock.

It took a while to locate an old can of Hercules 2400 but a forum member, Shuz, came across with one. He lives in Spokane so it took some coordination to get it transported to me on the other side of the state. Many thanks should be given to Shuz and his daughter who made this test possible.

The cardboard cylindrical “can” of Hercules 2400 was unopened and I cut the plastic end off the little plastic spout. The bottom of the can was marked “Shift 1”, 02400 066, 12693. The plastic “can” of Alliant 2400 has a lot # of CE0519 on it and was purchased last year before the rush.

The 44 magnum bullets were cast of WWs+2% tin in a RCBS 44-250-K double cavity mould. Bullets were inspected for complete fill out and other defects but other than that were non selected. The bullets fully dressed weighed 254 grains. The bullet lube used was Javelina and bullets were sized .430 in a Lyman 450. Cases were new, unfired, Winchester WW Super manufacture. Primers were Federal 150s and CCI 350s. Cases were sized and loaded in RCBS dies. A heavy roll crimp was applied in the bullets crimp groove as a separate step. AOL was 1.705”. Powder charges were weighed on a Redding scale.

The 30-30 bullets were cast of the same alloy in a Lyman 311466 double cavity mould. The bullets were visually inspected only for defects. The Hornady gas checks were pre seated then the bullets were sized and lubed with Javelina in a Lyman 450 with a .314 H die. The bullets were then pushed through a Lee .311 sizer. The fully dressed bullets weighed right at 160 gr. The .311 sized bullets when loaded in the FC 30-30 cases gave a very tight slip fit in the chambers neck. Cases were full length sized in an RCBS X-die die with a Lyman .31 M-die used to expand the case mouth and a 7mm seating die used to seat the over diameter bullets. Primers were Winchester WLRs. The bullets were seated with the front diving band just off the lands putting the GC right at the base of the case neck. AOL was 2.45”.

Test; the test strings for the 44 magnum consisted of 10 shots each for 20.5, 21, 21.5 and 22 gr of both Hercules and Alliant 2400. At 21 gr I also fired the additional test string of 10 shots using the CCI LP magnum primer. The target for the 44 magnum was at 50 yards. The start screen was 16 feet from the muzzle. The 30-30 test strings were also of 10 shots each and consisted of 16 gr of each of the 2400s. The target for the 30-30 test was at 100 yards. The start screen for the 30-30 test was 15 feet from the muzzle.

The temperature during the test range from 39 to 43 F. There was no wind to speak of. As is my usual practice when I set up the M43 I fired a 5 shot test string with a specific .308W rifle and one lot of M118SB as “reference ammunition” to ensure the M43 set up is good. This same specific rifle is used with a clean bore and the same lot of very uniform ammunition each time I set up the M43 for a test. In this case the reference ammunition test velocity and psi data readings were well with in norm for the 39 F temperature. All was good with the M43 set up so I conducted the test. At the conclusion of the 44 magnum test I cleaned the barrel and also ran 2 jacketed loads through it as a reference. This was a factory load and another standard load with a jacketed bullet. The ballistic information on these is also included for reference. Added: With regards to the seemingly low psi; this test was conducted at 39 -43 F. A check of previous test with this same bullets and same lot of 22 gr of Alliant conducted when the temperature was in the high 70s revealed an increase of 5,000 psi over what was obtained in this test. Obviously the ambiant temperature is a variable that must be considered.

Data and remarks; I will list the data for each charge as; H2400 (Hercules 2400) or A2400 (Alliant 2400) /velocity (adjusted to muzzle)/SD (Standard Deviation)/ ES (Extreme Spread) and under that will be the MAP (Mean Average Pressure)/SD/ES. All velocities, SDs and ES are in feet per second. All MAPs, SD and ES are in psi(M43). Keep in mind that pressure data and velocity data are not absolutes. There are expected variations between test strings of the same lot of ammunition and also between lots of components, especially powders. Alliant, of course, does not reveal the variation between lots of any powder. I do know that it was acceptable for a +/- 5% variation (10% variation possible) between different lots of IMR 4895. This is why some lots shoot ‘faster” or “slower” than other lots of the same powder. Also keep in mind that factory published psi and SAAMI psi are maximum allowable average pressures for specific cartridges. That does not mean every one of those cartridges are loaded to that psi level. Quite the contrary most factory and arsenal ammunition are well below those published figures, a “fudge factor” if you will.

The 44 magnum cartridge has a SAAMI MAP psi, using piezo-electric measurement, of 41,000 psi or 36,000 C.U.P. (Copper Unit Pressure). Also keep in mind that I am not using a SAAMI spec test barrel. I am using a production barrel with more than likely specs that are not at minimum like the SAAMI specs. Thus we can expect somewhat less velocity and attendant less pressure out of the Contender barrel than we would get with identical loads out of a SAAMI spec test barrel. For that very reason I would not load to the SAAMI max of 41,000 psi in this barrel. In my experience with the M43 and psi measurements in production barrels I would consider 35,000 psi(M43) to be a maximum load for the 44 magnum in a production barrel such as the Contender’s.

20.5 gr
H2400; 1365/17/56
25,700/900/2,700

A2400; 1425/13/41
26,000/600/1,900

21 gr
H2400; 1436/18/53
28,900/1,100/3,100

A2400; 1466/14/47
27,200/600/2,200

21 gr with CCI 350 magnum primers
H2400; 1438/17/51
27,100/1,000/3,000

A2400; 1474/19/60
27,300/1,100/3,200

21.5 gr
H2400; 1455/18/55
26,500/900/2,400

A2400; 1468/18/58
27,000/800/3,000

22 gr
H2400; 1493/20/57
27,000/700/2,000

A2400; 1515/14/47
27,900/700/2,400

Magtech 44 magnum factory ammunition; 240 HHP, 17.2 gr flake powder
1376/24/72
25,100/1,700/6,100

Hornady 240 gr XTP/24.5 gr H110, R-P cases, WLP primer
1540/16/46
31,200/1,500/4,700

From the above data, with the exception of the 21 gr data, we see that the Alliant 2400 appears to be “hotter”. However, the difference is less than 2% which is probably well within acceptable lot to lot variation. The 21 gr load where the Hercules 2400 is “hotter” is even less that 2% variation. Note that the 21.5 gr load of Hercules 2400 has 2,400 less psi than the 21 gr load of Alliant 2400 but still has a slightly higher velocity….such are the variances and why there is an acceptable variance. It is also why the “fudge factor” is built in. Were all the loads of Alliant 2400 “hotter” than the Hercules 2400 we could safely say, at least from this test, that this lot of Alliant 2400 is “hotter” than this lot of Hercules 2400. However that is not the case. With this test it appears both powders fall within lot to variation of a specific powder.

The Magtech factory ammunition is fairly indicative of current factory velocities and pressures. The Hornady XTP load is a popular load for that bullet and you can see the velocity and psi is up there. Lyman lists 23.4 gr of 2400 as a max load with their 429421 in the 3rd edition of their Cast Bullet Handbook. I can not disagree with that psi wise given the results of this test.

As to accuracy I have found with PB’d cast bullets used loaded in revolver cartridges and shot in other Contenders, revolvers with 6”+ barrels and rifles that accuracy starts to go above 1400 – 1450 fps and so it was with this test. The 21.5 gr load of both Hercules and Alliant 2400 with the CCI magnum primers proved to be the most accurate load on target even though the standard Federal primer load had slightly better internal ballistics. A repeat of the test could very well reverse that as the difference between the two powders internally or accuracy wise wasn’t enough to consider remarkable. I would use either load in this Contender barrel for hunting.

30-30
The 30-30 test was rather straight forward with only one charge of each powder tested. I will list the data in the same format;

16 gr
H2400; 1861/19/53
42,400/5,600/15,600

A2400; 1873/11/41
42,000/1,400/3,800

Remarks; 2400 is reputed to be a fine powder for midrange cast bullet loads with a filler not being necessary. It also is supposed to be non-position sensitive. I will agree with that to the extent if heavy for caliber cast bullets are used such as 190 – 220 gr bullets. My experience of years ago with medium weight bullets was born out again by this test, 2400 is not an efficient powder for medium or light weight bullets and with such is, indeed, position sensitive. The first 3 shots were foulers and no effort was made to position the powder in the case. The ES was from 1688 fps to 1822 fps. That was unacceptable. I thus conducted the Hercules 2400 test by raising the muzzle about 45 -60 degrees before shooting to position the powder to the rear of the case. Even then ignition was not what I would call consistent with the Hercules. With the Alliant I raised the muzzle to 90 degrees before shooting and the ES of the psi improved dramatically. There were also pressure spikes both up and down when the bullet was about 2/3s down the barrel. The pressure spikes were not any where near the MAP pressures but it showed uneven ignition and burn of the powder. Note also that the Alliant 2400 gave a lower MAP than the Hercules 2400 even though the velocity was slightly higher. Even with the large psi ES of the Hercules 2400 the average pressure of the 2 powders is so close that they again, in the 30-30, fall well within lot to lot variation of a specific powder.

Conclusion; Alliant says they didn’t change the formula for 2400 and you can’t prove by me otherwise. With cast bullets I shall to use 22 gr of Alliant 2400 under the 250 gr "Keith" style cast bullet in the 44 magnum as that load shoots very nicely in my Ruger 50th Anniversary BHFT at 1350 fps.

Caveat; I did not conduct any test with Alliant 2400 and jacketed bullets of 240 grain weight and the results of my test are not to be inclusive of them. It is expected that the pressures would be higher but since I have not ran a test all I can say is stick with current published data when using jacketed bullets and either Hercules 2400 or Alliant 2400.

Larry Gibson

**Silvercreek Farmer** · 12-26-2022, 08:54 AM

https://castboolits.gunloads.com/sho...t=larry+gibson

35 Remington Pressure Tested Loads

Test rifle is a M91 Mauser rebarreled with a 26” Shilen sporter barrel with a 14” twist as sold prethreaded and 35 Remington short chambered for SR Mauser actions by Brownell's. I finish reamed the chamber with a chamber reamer I had made to minimum SAAMI specification and headspace was set at minimum. The M91 is still in cut down military stok. Sight are a Lyman SME receiver sight with an M14 front sight.

Pressure and velocity were tested with an Oehler M43 PBL. Cartridges were loaded with RCBS dies. The case mouths were mildly crimped in the canalure and crimp grooves on the rifles.

The SAAMI MAP for the 35 Remington is 33,500 psi in deference to the older recoil operated semi automatic rifles for which the cartridge was first developed. I many single shots, the marlin 336 lever actions and bolt actions the pressure can be raised increasing the efficiency of the 35 Remington considerably. The Marlin 336 while chambered in 35 Remington has been mostly chambered in 30-30. Thus with the M336 being made to handle the 30-30 SAAMI MAP of 42,000 psi I see no reason why 35 Remington cartridges can not be loaded to that level for the M336 Marlin lever action rifles.

I used 2 different loads for “reference ammunition”. The first was a specific lot of Federal factory PowerShok loaded with 200 gr RNSPs. The Federal technician wouldn't give the specific pressure tested data for that lot but advised it was just under the MPSM (35,500 psi) for the cartridge. The second was a Lyman max load listed using H4895 powder in their 50th Edition Manual which listed a psi of 32,400 psi. I replicated that load all except for the bullet. I did not have any Hornady 200 gr FTX but used 200 gr Remington CorLoks. The FTX is seated much deeper into the relative small 35 Remington case with Lyman showing it as a compressed load. The Remington bullet seates to the base of the neck leaving airspace between the powder and the bullet. Thus, I expected the psi of the “reference” test load to be a bit less than the listed Lyman load.

All tests are 10 shot tests. The M43 PBL converts the velocity to the muzzle [remember this is from a 26” barrel].

Test data of the two “reference” loads;

Federal Factory 200 gr PowerShok

Federal F-C cases
Federal 210 primers
38 gr ball type powder
OAL; 2.471”
Velocity; 2286 fps
SD/ES fps; 19/53
PSI (M43); 35,200 (just under the MPSM)
SD/ES psi; 1,000/2,900

Lyman 50th Edition Handbook replication test load

R-P cases
Rem 9 ½ Primers
36.0 gr H4895
OAL; 2.522”
Velocity; 2065 fps
SD/ES fps; 39/100
PSI (M43); 30,000 (less with the shorter seating depth of the Remington 200 gr bullet)
SD/ES psi; 1,800/5,300

Remington 180 gr FPJ bullet w/LeveRevolution

Win Super cases
CCI 200 primers
45.0 gr LeveRevolution [100% load density]
OAL; 2.457”
Velocity; 2407 fps
SD/ES fps; 16/57
PSI (M43); 32,100 (just under the MPSM)
SD/ES psi; 1,200/3,600

Remington 200 gr RNSP bullet w/LeveRevolution

Win Super cases
CCI 200 primers
42.0 gr LeveRevolution
OAL; 2.457”
Velocity; 2249 fps
SD/ES fps; 31/109
PSI (M43); 30,900
SD/ES psi; 1,200/3,600

Remington 200 gr RNSP bullet w/LeveRevolution

Win Super cases
CCI 200 primers
45.0 gr LeveRevolution [100% load density]
OAL; 2.457”
Velocity; 2425 fps
SD/ES fps; 16/41
PSI (M43); 36,300
SD/ES psi; 1,200/4,300

RCBS 35-200-FN cast of COWW + 2% tin, Hornady GCs, 2500+ lube, sized at .360

R-P Cases
WLR Primers
37 gr IMR4895
OAL; 2.425”
Velocity; 2162 fps
SD/ES fps; 50/140
PSI (M43); 41,100
SD/ES psi; 2,400/6,800

RCBS 35-200-FN cast of COWW + 2% tin, Hornady GCs, 2500+ lube, sized at .360

Win Super Cases
CCI 200 Primers
45 gr LeveRevolution
OAL; 2.427”
Velocity; 2384 fps
SD/ES fps; 28/85
PSI (M43); 37,900
SD/ES psi; 2,000/5,900

NOE 35 XCB 230 gr cast of COWW + 2% tin, Hornady GCs, 2500+ lube, sized at .360

Win Super Cases
WLR Primers
42 gr LeveRevolution
OAL; 2.453”
Velocity; 2314 fps
SD/ES fps; 18/59
PSI (M43); 41,800
SD/ES psi; 1,100/3,400

The use of LeveRevolution powder in the 35 Remington cartridge certainly boost the performance quite a bit. None of the reloads tested exceeded the SAAMI MAP for the 30-30 and, thus, they should be usable in Marlin 336 rifles, SS actions and bolt action rifles. chambered in 35 Remington.

**Silvercreek Farmer** · 12-26-2022, 08:55 AM

https://castboolits.gunloads.com/sho...-RPM-Threshold

The RPM threshold is area of velocity where the RPM created by the twist accentuates the defects in cast bullets creating excessive yaw, wobble and pitch of the bullet during flight. Defects in cast bullets are caused by imbalance due to out of round casting, other casting defects, or unwanted obturation during acceleration. Exactly where that threshold is depends on numerous things but those that mostly affect the threshold are; burning rate of powder, quality of cast bullet, design of cast bullet, alloy, fit of bullet to throat/leade and twist of the rifling. I've found over the years that with normal commercial moulds generally available (what most of us use), casting quality bullets of WWs or harder, with proper lube and fit to the throat when using medium to slow burning powders the threshold is in the 125-140,000 RPM range. If we are using the old '06 with a 10" twist and 311291 then the threshold translates to somewhere between 1735 fps and 1944 fps we will find the best accuracy when using 4895 or a slower burning powder.

With a faster powder such as 2400 best accuracy will come at a little slower velocity as the faster powder has a faster acceleration. This means unwanted obturation will occur at lower velocity so accuracy will deteriorate quicker than when the medium/slower powders are used.

The cast bullet bench rest boys really slow twists down which does help considerable. If one is building a special purpose cast bullet rifle then twist is of major importance. My 14" twist Palma barrel (27.5" long) in .308 Winchester shoots regular cast bullets (30-15--FN, 311291, 311041, 311299) with excellent accuracy in the 2400+ fps which is 125,000 RPM, right at the beginning of the threshold. Really, really best accuracy comes down in the 21-2200 fps range which is around the 110,000 RPM area Junior1942 talks about. Same bullets in my M70 target with 12" twist 26" barrel loose accuracy at the same RPM as the 14" twist barrel. My M788 with a 10" twist 22" barrel does exactly the same. With the 12" twist that is in the 21-2200 fps range and with the 10" twist it is in the 1740-1940 fps range.

I've found that most regular heavy for caliber cast bullets shot out of regular rifles shoot best in the 125-140,000 RPM range with medium to slow powders. One merely must know the twist of the rifle to figure what the velocity range for best accuracy will be.

**Silvercreek Farmer** · 12-26-2022, 09:03 AM

https://castboolits.gunloads.com/sho...-XCB-600-yards

NOE 30 XCB, 30x60 XCB, 600 yards

Lots of pics on this one too, so best to follow the link.

**quack1** · 12-26-2022, 09:34 AM

This thread definitely needs to be added to the sticky list.

**Silvercreek Farmer** · 12-26-2022, 09:35 AM

https://castboolits.gunloads.com/sho...h-three-twists

https://castboolits.gunloads.com/sho...ists-Chapter-2

Chapter 1; the test criteria

So why is it that when we push our cast bullet out of our accurate 30-06 we get very good accuracy at 1800 fps or so but when we push the bullet to 2100 fps we get pretty poor accuracy? Is there really an RPM threshold for cast bullets which establishes where the accuracy capability will deteriorate if the RPM threshold is exceeded? That seems to be the question. Just what do we mean by “RPM threshold”. The RPM threshold is that range of RPM where almost all cast bullets will lose accuracy if exceeded. For practical purposes when using a gas checked cast bullet with a BHN of 14-18 the RPM threshold is between 125,000 RPM and 140,000 RPM. But let us remember here that a “threshold is not a ‘limit’.

Thus those RPM threshold figures are not hard and fast as some things like a too soft alloy or too fast a powder can lower the threshold. Conversely, other things like a harder alloy or a slow burning powder can raise the threshold. However the RPM threshold is pretty consistent when we use cast bullets of designs that are readily available through commercial venders and are what most cast bullet shooters use. It is also these same designs that commercial bullet casters offer. Given a medium or slow burning powder we know that accuracy improves as the consistency of the internal ballistics improves. At a certain velocity accuracy begins to deteriorate. Since the RPM of a bullet is directly related to the twist (or show fast the bullet spins) of the barrel and the velocity at a certain point the RPM creating higher centrifugal force) overcomes the rotational stability of the bullet and accuracy decreases. The RPM threshold can be lower or the RPM threshold can be crossed into higher velocities if we use specialized cast bullet designs or tweak the loads in other ways. But for the most of us who use regular cast bullets the RPM threshold appears to be real and we need to understand it.

For a bullet to fly straight the center of form should coincide with the center of gravity and the center of spin must then coincide as closely to those as possible. When these centers do not coincide we have an unbalanced bullet that does not fly straight. A bullet thus imbalanced may wobble, it may yaw and/or its flight path may corkscrew around the intended flight path. The degree of these imbalances directly affects the accuracy or the ability to hit the same spot on the target. In basic terms an imbalanced bullet does not fly straight.

Can we demonstrate an increase in RPM above a certain threshold overcomes the rotational stability and decreases accuracy? Can we measure if and when bullets become more imbalanced? Will there be a direct correlation between measurements of imbalance and inaccuracy? All of these are good questions and the answer to all of them is yes. Let me explain but first I will describe the 3 test rifles.

All three rifles are chambered in .308 Winchester. All three are accurate with jacketed bullets and cast bullets. All three have free floated barrels. The three rifles have three different twists. The three test rifles used are; the 10” twist rifle is a M1909 Argentine Mauser with a 24” heavy sporter barrel. It has a Timny trigger set at 2 lbs. It has a 10X Weaver MicroTrac scope on it. This rifle is capable of consistent MOA accuracy with quality bullets. The 12” twist rifle is a M70 varmint rifle with heavy 26” barrel. The trigger is also set at 2 lbs. It has a 3x12 Redfield Ultimate scope on it. This M70 is capable of ½ MOA with match bullets. The 14” twist rifle is a M98 Mauser with a 27.5 barrel of Palma taper and weight. It too has a 2 lb trigger. This rifle has a 16X Weaver T16 on top. It is also capable of ½ MOA with match bullets.

What about the test loads? Well I will use the exact same loads in all three rifles. I will compare the accuracy of each rifle unto itself. In other words each rifle and it’s bullets flight will tell us when that rifles accuracy begins to deteriorate. The loads used in all three rifles will be the same and it is then when accuracy deteriorates in one rifle the RPM of that rifle with that load is comparable to the RPM of the same load in the other rifles.

Now to explain how we can measure if and when a bullet becomes imbalanced. I will use an Oehler M43 Personal Ballistics Laboratory to provide these measurements. The M43 will tell us the Time Of Flight and give us the Ballistic Coefficient of the bullet by measuring the muzzle velocity and the down range velocity. Along with the TOF and BC it will provide Standard Deviations and Extreme Spreads for these. A bullet that is not flying straight (imbalanced and inaccurate) will slow down quicker, have a lower BC and the SD/ES at the down range screens will be greater than that of a bullet that is flying straight (balanced and accurate). Thus if we have a bullet that is shooting accurately and as we increase velocity, with the attendant increase in RPM,
the accuracy decreases it tells us the increased centrifugal force of the higher RPM has overcome the rotational stability of the bullet and decreasing accuracy is the result. The M43 will also measure the chamber pressure of each round fired so we may compare how pressure may be affecting the bullet.

Now wait a minute you say, by increasing velocity we are increasing acceleration and the bullet is deforming in the bore through obturation and set back. That is the reason for the poor accuracy. Well that sometimes may be the case. However remember, we are using the same loads in each rifle so if the 10” twist rifle becomes inaccurate before the 12 and 14” twist rifles with the same load then we can assume it is the increased RPM of the 10” twist barrel is the culprit. Then if the 12” twist rifle also becomes inaccurate before the 14” twist rifle, all with the same load, then we have confirmed it is the increased RPM that is causing the inaccuracies.

To demonstrate the validity of these test methods a simple test was conducted with the 10” twist rifle. The M43 was set up with testing done at 100 yards. M118 Special Ball was used for the test. Now I think we can agree the 174 gr M118 bullet is not going to suffer any set back, bending, torque twisting or undue obturation during acceleration. At any rate, the test here is between regular M118 bullets and those I purposely unbalanced. If the regular M118 bullet suffers any of the mentioned deformations then the unbalanced M118 bullets would suffer the same deformations. So what we are testing is what the different effect of RPM will be on the balanced and unbalanced bullets.

This lot of M118 ammo, while 1.1 – 1.2 moa accurate in 12” and 14” twist barrels has not been much better than 2 moa in 10” twist barrels including M24 sniper rifles. And so it was with the M1909 with 10” twist. A ten shot string of regular M118 bullets was fired and they grouped right at 2 MOA. Then the ten shot string was then fired with the same lot (actually with the other 10 rounds out of the same 20 round box) of M118 that I had drilled a hole in the side to unbalance the bullet. I used a #31 drill and drilled the hole .06” deep removing 1.7 gr of the bullet in the side right in front of the case mouth. The M43 showed that the unbalanced bullets, when compared to the regular M118, averaged 5 fps faster MV, had a slower TOF, down range velocity was slower and had a lower BC. This is ample evidence the unbalanced bullets were not as stable in flight as the regular M118. The clincher was the group. The regular M118 grouped 2 MOA and the unbalanced M118 grouped into 6 MOA. Ample evidence of how the centrifugal force of the RPM affects the accuracy of unbalanced bullets. A picture of the two groups is attached.

How does this apply to cast bullets? Well most all cast bullets we cast are not perfectly round nor does the center of gravity coincide with the center of form. How much the cast bullet obturates, sets back, the nose bends to one side or the lube grooves collapse during acceleration depends on the hardness of the alloy and the fit to the throat. We should realize our beloved cast bullets for the most part are fairly unbalanced once they leave the muzzle. However with a normal alloy like WWS or #2 alloy GC’d cast bullets seem to withstand all this fairly well and given a reasonable fit to the throat they have good rotational stability and shoot accurately up to a certain point. It is at that point the centrifugal force of the RPM overcomes the rotational stability and the bullet shoots less accurately.

I intend to initially test two bullets; 311291 and 311466. Both will be cast from Lyman 2 cavity moulds. Alloy will be air cooled and the bullets have a BHN of 15-18. The gas checks will be Hornady’s and are seated with the Lyman 450 GC seater prior to sizing. The lube will be Javelina. Bullets will be sized in the Lyman 450 using a .311 H die. Powder will be H4895 with a ½ gr Dacron filler. Loads will work up in one gr increments from 26 to 36 grains. Cases are LC with the necks inside reamed with a Lee Target Loader for concentricity. All cases have been fire formed in their respective rifle and neck sized with a Forster/Bonanza Benchrest NS die. A Lyman .31 M die is used to expand the necks and flair the case mouths. The bullets are seated to just slightly engrave on the lands. Additional loads tested will be with two slow burning powders; RL19 and H4831SC.

Expected test velocities are expected to run from 1700 fps up through 2600 fps. Approximate RPM range of those velocities with each twist are:

10” twist; 122,500 – 187,000 RPM
12” twist; 102,000 – 156,000 RPM
14” twist: 87,500 - 134,000 RPM

When consistent high velocity loads (internally ballistic uniformity) are found additional tests will be conducted with the 10” twist rifle as it has the highest RPM potential. Those additional tests will be with different lubes (Lars), with the bullets water quenched out of the mould, will bullets cast of linotype and with bullets of various sizing (.311, .310, .309 and .308). Of course only one change will be tested at a time in an effort to see if the HV loads can be “tweaked”. I will even, to appease Bass, test with different barrel pressure.

Tests with the cast bullets will begin soon. Stay tuned for Chapter Two.

Larry Gibson

Addendum to Chapter 1; A picture of the two groups (regular M118 and unbalanced M118) are attached. Also, Glen's suggestion is an interesting thought. My thoughts on using a faster powder are since those who use the faster powders mostly use WWs that that would be the alloy to use. Just for sake of keeping it manageable three powders could be used, suggestions? I Could run that test at the conclusion of this test.

**Silvercreek Farmer** · 12-31-2022, 06:38 AM

https://castboolits.gunloads.com/sho...s-Alliant-test

Blue Dot; Hercules vs Alliant test
All

As promissed I finally had some decent weather and conducted the test. It is lengthy and will require several posts to put it all together.

Hercules Blue Dot VS Alliant Blue Dot; .44 Magnum

Date: 15 April, 2009
Location: Tacoma Rifle and Revolver Range, University Place, Washington
Time: 1300 – 1600
Temperature: 43 – 50 degrees F.
Atmospheric pressure: 29.92
Wind: 2-5 mph from 0530
Test instrument: Oehler M43 Personal Ballistics Laboratory
Test Cartridge: .44 Magnum
Test Case: WW Winchester
Test primer: Federal 150 Large Pistol
Test Powders:
Hercules Blue Dot lot #BD152 purchased 10-15+ years ago as the price was $11.89
Alliant Blue Dot lot #289 shift 2, Feb 22, 2008 with a price of $20.89
Powder charge weights: 14.5 to 18.4 gr in .5 grain increments with all charges weighed on a Redding
powder scale
Test Bullet: RCBS 44-250-K cast of 60-40 WW (new) – linotype alloy, weight 252 gr, sized .430 in
Lyman 450 and lubed with Javelina
Load OAL: 1.705”
Crimp: Case mouth crimped completely under edge of forward driving band
Loading dies used: RCBS with carbide sizer
Shots in test string; 5
Test sequence: a test string was fired with the Hercules powder then the subsequent test string was of the same charge weight of Alliant powder. Thus test strings were concurrent from 14.5 gr up through the 18.4 gr powder charge weight

Results:
The M43 PBL provides much information that would result in an overly long report. Pertinent to the question of the difference between the older Hercules Blue Dot and the new Alliant Blue Dot is the comparison of velocity and pressure per a equal charge weight of each powder. Thus I shall report the muzzle velocity (corrected to muzzle by the M43) and the pressure (rounded to nearest 100 psi so 20,500 psi will read 20,5) for each powder charge weight of both Hercules and Alliant Blue Dots. The format will read the powder charge with the initial H or A in front, the muzzle velocity and the pressure in psi(M43).
H14.5/1330/24,3
A14.5/1310/25,2
H15/1368/26,3
A15/1340/27,4
H15.5/1412/28,5
A15.5/1380/28,3
H16/1447/30,4
A16/1438/31,6
H16.5/1493/32,6
A16.5/1464/31,4
H17/1521/32,4
A17/1498/32,8
H17.5/1541/31,4*
A17.5/1527/31,4*
H18/1565/29,1*
A18/1569/24,4*
H18.4/1589/20,5*
A18.41583/23,0*

* Note; these pressures are not misprints.

Discussion/conclusion; the tests proved interesting to say the least. I did not find any incident or indication of “pressure spikes”. To the contrary I found that as the load (17.5 gr and above) exceeded 100% loading density and be came compressed the pressure curve became longer with less pressure. As the powder charge increased and compression of the powder charge became greater the bottom literally fell out pressure wise. The velocity increase per increased powder charge also began to lesson. I discussed this at length with Dr, Oehler. While he modestly says he is not a ballistician (he is a gentleman of the old school) he thinks that ignition is a problem with the compressed loads. A magnum primer may or may not improve ignition and would have to be tested.

Quite frankly I find the 17 gr load of either the Hercules or the Alliant Blue Dot powder to be a good practical maximum with this bullet. Looking at the graph of PSI vs Powder charge we see that 17 gr is the peak with both powders. However when we look at the graph of FPS vs Powder charge it is difficult to make that distinction when comparing them to each other. The old Hercules Blue Dot loading data per Lyman was 15 to 18.4 gr with the 429421 cast bullet. The new Alliant Blue Dot data as per the “New Edition” 48th Lyman manual is 14.5 to 16 gr with that same 429421 cast bullet. Interesting to note is that with 429244 they listed 14 to 17.4 gr of Alliant Blue Dot. The Lyman pressures are lited in CUPs which aren’t directly convertible to psi so I won’t go there.

Keep in mind also the TC Contender hasn’t the long throat or the barrel/cylinder gap of revolvers. Thus the pressures in revolvers would no doubt be a little less per given powder charge. I will work up the same loads with Alliant Blue Dot from 14.5 to 17.5 gr in the ½ gr increments. I will then test these in my Ruger BH 50th Anniversary with 6 ½” barrel. Of course I do not have a strain gauge on the Ruger so I will be depending on the chronographed results to give indications of a good load, a bad load or “pressure spiking’.

I’ve graphed out comparing the FPS gain per charge weight and the psi gain per charge weight.

Looking at both graphs it is apparent that with this test both the Hercules and Alliant Blue Dots are within normal lot to lot variation of each other. Basically, based on this test with a normal weight range cast bullet, there is no apparent difference between them either in burning rate or burning characteristics. Further testing with light weight jacketed bullets is in order but with the current situation I’ve not been able to find either 180 or 200 gr .44 jacketed bullets. Further testing in other cartridges such as the .357 and .41 magnums is in order also.

The photo of the fired cases is as they were fired in order. The green box contained the Hercules loads and the red box the Alliant loads. There was no indication of cartridges stick as all were easily extracted from the chamber of the Contender barrel with fingers. There is no appreciable indication of pressure by the look of the primers.

I shall continue to use Alliant Blue Dot as I find it to be a very fine powder for certain applications as id found the old Hercules Blue Dot to be. When using Alliant Blue Dot in a cartridge for which I only have older Hercules Blue Dot loads I will carefully work up loads again. I suggest anyone taking this data to do so with caution and work up your own loads as per instructions in all loading manuals.

Larry Gibson

**No_1** · 12-31-2022, 08:01 AM

Done.

Members, please abide by the OP’s below condition: This is not a discussion thread. All discussion will be removed without notice.

Rob

Originally Posted by Silvercreek Farmer

Not a discussion thread! Please follow the provided links if you would like to discuss the topic!

With Larry’s permission, I’m starting a thread to compile his posts containing load testing information. Larry has posted a lot of great data over the years, and hopefully the mods will find it sticky worthy. Feel free to help with this project. Please copy and paste the post as well as a link to the original thread. Thank you.

**Silvercreek Farmer** · 12-31-2022, 04:26 PM

https://castboolits.gunloads.com/sho...-06-M2-bullets

There were 3 different levels (velocities) of M2 Ball with the 152 gr FMJ flat based bullet produced. The black tipped armor piercing ammunition also had the M2 nomenclature but I'll disregard it here. In the last 10 years or so I have chronographed and pressure tested various lots of M2 Ball and a couple lots of M1906 Ball ammunition. I have chronographed them in my M1903 and in my pressure test rifle all which have 24" barrels. The 3 different levels of M2 ammunition are readily apparent.

I measure the pressure in psi" not CUPs sometimes still referred to as "psi", particularly in older literature and manuals. The SAAMI MAP for CUP measurement was 50,000 CUP and the MAP for PSI measurement (transducer/gauge) is 60,000 psi. Thus the 50,000 of the CUP measurement is equivalent to the 60,000 psi of the transducer/gauge measurement. As Scharfschuetze mentions the MAP for M2 Ball was 47,000 CUP or about 56,500 psi as measured by transducer/gauge. TM 9-1305-200 Small Arms Ammunition, US Army, dtd June 1961 specifies 45,000 to 50,000 psi (CUPs) for M2 Ball.

The M1906 ammunition tested produced right at 2700 fps as specified out of a M1903. It produced about 50 fps more out of the minimal chamber spec test barrel and ran right at 56,100 psi.......exactly what it was supposed to do.

Again, as Scharfschuetze mentions, in the mid '30s the supply of M1906 ammunition was running out and it was found the M1 Ball ammunition exceeded the safety fan of many training ranges, particularly National Guard training ranges. A request was made for ammunition specification comparable to M1906 ammunition be made for training use. This was the 1st level of M2 Ball ammunition performance. That specification called for 2700 fps with the 150 - 152 gr FMJ FB'd bullet. Just day before yesterday I tested a lot (DM 42) of that level of M2 Ball. It ran right at 2701 fps with 55,600 psi.

The 2nd level of performance of M2 Ball ammunition result in 1939 - 1940 when the National Guard Bureau requested a further reduction of velocity of M2 Ball resulting from the establishment of many newer training ranges (the National Guard had been mobilized pretty much completely by 1939) which did not have the safety fans to safely contain the original M2 Ball or M1906 ammunition. The request was for the M2's velocity to be reduced to 2550 - 2600 fps. This was done and I've found most of the M2 Ball tested made after the mid '50s falls into this level of performance. The velocities of numerous such lots runs from 2490 fps to 2600 fps. It appears from my testing all 3 levels of M2 Ball were produced by various arsenals up through the mid '50s with only the 3rd level produced after the adoption of the 7.62 NATO cartridge to replace the 30-06.

With the development of better powders (notably 4895 and ball powders) for use in the 30-06 cartridge in the early '40s we see the velocity specification for M2 Ball ammunition was upgraded to 2810 fps and sometimes reported as 2820 fps. This created the 3rd level of performance. I have tested numerous lots of this level also. Day before yesterday I also tested a lot of SL 52 which was loaded with 48.2 gr of extruded powder (probably 4895). It produce 2801 fps at 54,900 psi.

For practical shooting with either M1903/M1903A1s or M1903A3s I like to match the level of M2 ball performance to what the sights are regulated for. Of course if one is just shooting at one range then the regulation of the sights range doesn't matter. I shoot multiple ranges with my M1903A1 which is why I load to match the sight regulation.

The M1903/M1903A1 sights are regulated for the M1906 Ball or M2 Ball that gives 2700 fps with the 150 - 152 FMJFB bullet.

The M1903As sight are regulated for the 3rd level of performance; a 150-152 gr FMJFB bullet at 2810 fps. This is why many were frustrated with level 1 and particularly level 2 M2 Ball performance in M1903A3s.....the sights just didn't work right.

Quality M2 Bullets are almost impossible to get. In all my testing I found a great degradation of accuracy in US made M2 Ball after the late 50s, particularly that produced in the '60s and early '70s. The bullets are just of poor quality. Thus I use 7.62 M80 bullets which hold 2 moa +/- out of my M1903A1. The commercial made Hornady's have always given me the best accuracy, usually 1 1/2 moa +/-. I got a bunch of pull down M80s from Widner's about 10 years ago that hold 2 - 2 1/2 moa +/-.

I use 4895 for my loads with M80 bullets and in my M1903A1 load them to 2640 - 2650 fps which regulates the trajectory to the sight quite close out to 1000 yards. For use in my M1903A3 I load the M80 bullets to 2730 fps which then regulates the trajectory to the sight ranges to 800 yards. The use of M80 bullets may be what you'll also find to be the best option.

Larry Gibson

As a side note; I have also tested a few lots of M1 Ball. Day before yesterday I also tested a lot of M1 Ball (FA 28) . The velocity ran 2638 fps at 57,000 psi.....again, just as it was supposed to do. A lot of M72 Match was also tested. It ran 2624 fps at 57,100 psi......just as it should have.

**Silvercreek Farmer** · 12-31-2022, 04:31 PM

https://castboolits.gunloads.com/sho...7-Magnum/page2

Having pressure tested both Hercules and Alliant 2400 under 150 - 162 gr cast bullets I've found 14.5 gr 2400 (doesn't matter which flavor as they are the same excepting lot to lot variation) under a 162 gr 358156 (fully dressed) and seat to and crimped in the forward crimp groove runs very close to the SAAMI MAP of 36,000 psi. The original loads were indeed heavier because at the time there was only the large N frame S&W revolver and the Colt Python revolvers made for the cartridge. Those level of loads were fine for those two revolvers as they were for the Colt and Ruger SAs chambered in 357 magnum. The problem arose with the introduction of the M19 K frame S&W revolver in 357 magnum. It was the darling of law enforcement for many years but it was quickly learned that a diet of those original loads would soon rattle the M19 apart. Thus the factories "dumbed down" 357 Magnum ammunition to the levels we have today. I have pressure tested quite a few various 357 magnum factory loads produced from the mid '60s through the late 2010 time frame. The tested psi's run from 23,000 upwards of 34,000 psi with most in the 28 - 32,000 psi range.

**Silvercreek Farmer** · 12-31-2022, 04:34 PM

https://castboolits.gunloads.com/sho...r-45-Auto-Load

Jeff Cooper 45 Auto Load

I believe, and had for many years, it is/was a typo printed in that column and in G&A's "Jeff Cooper on Handguns". I've many times read Cooper to say, and heard him say it once, the H&G #68 over 7.5 gr Unique was his suggested "social load" using a hard cast bullet. He also suggested any 200 gr hard cast bullet of 40 - 45 caliber at 1000 fps was about as good as it would get. I have never read what mould the "215" bullet actually was from. Perhaps someone knows?

For many years I've shot a lot of commercial hard cast (Greer and then Laser Cast) 200/205 gr cast SWC of facsimile to the H&G #68 over 7.5 gr of Unique in M1911/Combat Commanders with steel frames w/o any sign/hint of a cracked frame. I also use 18 lb recoil springs though. Velocities run 990 to 1050 fps.

Having pressure tested that load with Laser cast 200 gr SWCs and cast of Lee's 452-200-SWC I've found the pressures to run from 17,500 psi to 18,500 psi depending on the bullet weight and seating depth used. That is well under the SAAMI MAP of 21,000 psi for the 45 ACP.

My own 'social load" is the 200 gr Hornady XTP or Speer Gold Dot over 7.5 gr Unique. Velocity runs 1025 +/- fps out of my 5" M1911. The pressure of that jacketed bullet load runs 18,700 psi. Again, well under the SAAMI MAP.

Note; Testing Hornady 220 gr Critical Duty and CorBon 230 gr +p loads gave psi's out of the same test barrel right under the top end or 45 ACP+P MAP of 23,000. I was told they were loaded to SAAMI +P pressure. Thus the pressures are basically correct [there will always be a test to test variation] for the 7.5 gr Unique loads.

While I have shot a lot of those (they really tumble jack rabbits....) it is not my normal practice load not the load I used for IPSC. That load is the 200 gr SWC or 230 TC over 5 gr of Bullseye.

BP	Bronze Point	IMR	Improved Military Rifle	PTD	Pointed
BR	Bench Rest	M	Magnum	RN	Round Nose
BT	Boat Tail	PL	Power-Lokt	SP	Soft Point
C	Compressed Charge	PR	Primer	SPCL	Soft Point "Core-Lokt"
HP	Hollow Point	PSPCL	Pointed Soft Point "Core Lokt"	C.O.L.	Cartridge Overall Length
PSP	Pointed Soft Point	Spz	Spitzer Point	SBT	Spitzer Boat Tail
LRN	Lead Round Nose	LWC	Lead Wad Cutter	LSWC	Lead Semi Wad Cutter
GC	Gas Check

Thread: Compilation of Larry Gibson’s load tests

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Compilation of Larry Gibson’s load tests

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