Realistic .357 Mag velocity

[fatelk]

I've reloaded .357 Magnum for a long time, but have always wondered about velocities. A long time ago when I started, I remember reading that "the standard" for the .357 Magnum was a 158gr bullet at 1500 fps. That seemed excessive and I never was able to find a safe load that even came close, except back when I had my Dan Wesson with the 15" barrel (sure wish I had kept that one).

Over time I realized the effect of barrel length, and the fact that advertised ballistics are often not realistic. I came to the conclusion that 1300 fps in a 6" barrel wasn't that bad.

So, I'm getting ready to load up a bunch of .357mag. I have a bunch of brass prepped, and hundreds of Lee 358-158-RF bullets cast and powder coated, a batch that should last several years. I'm now revisiting an ideal load before loading them up. I have some AA #9, some H108, some 2400, and some H110. Of course accuracy is most important, but for velocity I'd like a load that is near the upper end while safe for S&W revolvers. Yes, I know that velocity isn't everything; I just want a realistic expectation for a good load.

Any thoughts or experiences along these lines?

[tazman]

I gave up worrying about velocity in revolvers. There are just too many things about an individual gun that can have an effect on velocity.
A few years back, I ran some tests with three different revolvers with identical loads shot on the same day using the chronograph.
To my surprise, the longest barrel shot slower than the other guns. It also tended to be more accurate.
Bore roughness, cylinder gap, and throat size make so much difference in what velocities will be achieved in any particular gun.
An accurately placed boolit will do the job. It won't matter if the boolit is going 1200 fps or 1350 fps.
Load a safe and accurate load and don't worry about the velocity.

[fatelk]

Yes, I get that. What I want to be able to do though, is to make reasonably full use of the energy potential of the .357 Magnum. Otherwise I'd just shoot .38s in it and be happy.

I don't have any way to measure chamber pressure, so I work up a load watching for pressure signs, and velocity comparison is a helpful tool too.

Added- sorry, didn't mean to disparage your reply. I agree with what you said, and I'm not really trying to chase velocity, just trying to get a realistic idea of where others are at, to help in load development. Thanks for the reply.

[454PB]

I have never bought factory loads for .357 magnum, and I've been shooting them for 45 years. However, I have acquired some factory loads in trades and when buying components from others.

I've owned a chronograph starting way back when they still used fragible screens that were good for one shot, and it's always been interesting to me to experiment with what can be safely done with handloaded ammunition. You would think I would not be surprised by much after all those years and literally thousands of rounds over a chronograph, but a few years ago it happened.

I was experimenting with Hodgdon Lil'Gun, mostly because of all the talk of barrel heating and forcing cone erosion. I started working up a load using Lil'Gun and some of my Lyman 357156 gas checked boolits. These were fired in my Ruger Security Six with a 6" barrel. The results were the first time I've ever had a 158 gr. boolit exceed 1500 fps., and I was still below Hodgdon's recommended maximum.

I normally prefer milder loads of Bluedot at around 1250 fps., but I was impressed to see that reading.

[dverna]

L’ll Gun will get you the highest velocity...if that is your goal.

[Win94ae]

Precise loads developed for my 8 inch 686; 1500fps for 125gr, 1250fps for 158gr, and 1050 for 180gr.
Precise loads developed for my 2.5 inch 66, 1350 for the 125gr, 1200 for the 158gr, and 900 for the 180gr.

But I don't use most of those, I use the 180gr load in the 686 at 1050fps. In the 66 I use a 1050fps 158gr load, and a 1050fps 125gr 38 special load. That is all I need.

[fatelk]

No, top velocity isn't necessarily the goal. It's just one factor; I'd just like to be ballpark with the best potential of the cartridge. I have some Lil'gun, but saving it for .410, cautious because of the bad rep it got in revolvers.

Looking at some charts for factory ammo, it looks like most standard 158gr factory rounds have a stated velocity of around 1250 fps. I do also have a couple pounds of Blue Dot. Maybe I should give it a try too. Now that I have some spare time, maybe I'll load up some rounds using several different powders and loads, and see what does best. I can compare H110, H108, AA#9, 2400, and Blue Dot.

[dtknowles]

I have not tried Lil Gun in my 357 and I have not shot any 150-160 gr. rounds that clocked over 1500 fps but I have shot the Lyman gas checked 158156 bullet over 15 gr. of H110 in my 8 inch barreled Dan Wesson Mdl 15 and it clocked at 1335 fps with groups less than 2 inches at 25 yards. That load is as hot as any recent production factory ammo I ever saw test results for.

This picture is of part of a spreadsheet I put together from various manuals and magazine articles. It lists only the max loads.

260657

The Hodgdon 2020 manual lists a few loads that push a 158 gr. jhp at over 1500 fps from a 10 inch barrel. That manual list my 15 gr. of H110 as the starting load pushing 1410 fps from that 10" barrel. Lil Gun in that manual give similar top velocities at over 1500 fps.

Tim

[dtknowles]

……...I normally prefer milder loads of Bluedot at around 1250 fps., but I was impressed to see that reading.

My data says that enough Blue Dot to get 1250 fps is pretty close to max.

Tim

[megasupermagnum]

H110 with 158 grain jackets bullets were doing 1450 fps from a 4 5/8" blackhawk with listed max load. I pushed them all the way to 1550 fps before finding pressure signs. They were very accurate too.

[Larry Gibson]

The max loads listed in Lyman's CBH #4 for the 158 RF cast bullet should net you velocities in the 1300+ fps range (that's what I've gotten out of several different 6" barreled revolvers) with 2400 and H110 at pressures (measured by me in a Contender barrel via Oehler M43 PBL) close to the SAAMI MAP for the 357 magnum. Blue Dot will net about 100 fps less at MAP psi.

If Your S&W revolvers are L or N frames then those loads are fine. If K frames then a steady diet will loosen thinks up....not "dangerous" per se but such full power loads aren't recommended for the lighter framed "K"s.

BTW; the original "1500 fps" loads were with the 8 3/8" barrel N frame S&Ws. Also the original 357 mag loads that did 1500 fps out of the 8 3/8" barreled N frames was a bit warmer than todays SAAMI max MAP loads. However, a 358477 (150 gr SWC) loaded over a SAMMI MAP psi load of 2400 will run 1500 fps out of an 8 3/8" N frame 357 magnum and close to 1400 fps out of my 6" Ruger SS.

[shooting on a shoestring]

My take is the word standard. If interpreted as normal, no. If interpreted as standard by which others are judged, yes.

I’ve chronographed multiple loads using a range of 150-160 grain boolits in 4&5/8” Blackhawk and 4” GP100 at 1500 - 1550 fps. BUT, these were all worked up to maximum effort loadings. AND the muzzle blast was HEAVY! These are not typical of what I load in 357.

I typically load the 150-160 grain class of boolits to 1300-1400 fps and consider these to be my heavy hitters In 357. These can go in my other guns like Model 19, Security Six and Uberti.

My standard, shoot a lot, have fun loads are mostly Herco loads running 1100-1200 fps.

[mnewcomb59]

Lead 158s will get 1400 pretty easy in a 6" with 2400. Depending onseating depth of the bullet it will happen somewhere between 14.5 and 15.3 gr.

Lil' Gun will get 1550fps in the 6" but I save those for the rifle because they are hard on forcing cones, not because they are over pressure.

[smkummer]

So glad I gave up trying to achieve a number in a book. My unique charged reduced 158 LSWC cast bullet at 1100 FPS plus does everything I want to 200 yards. I’ll admit through I do load a 125 JHP fast for specifically blowing up 2 liter plastic soda bottles.

[fatelk]

Thanks guys. That gives me a lot to work with.

I see it a little like seeing how fast my car will go. No, I'm not going to drive 120mph very often, but it is nice to know where the limits are and what it will safely take.

I have a S&W model 66 and a 686. I shoot .38 Special in them more often than not. The few hundred rounds of .357 mag I'll be loading should last me for several years. Like I said, I just want to find a good, safe load that lives up to the potential of the round in those guns. I'm not going to push it because I don't want to wear out my old Model 66. :)

[megasupermagnum]

While I've gotten impressive speed from 158 grain, I personally prefer bullets in the 170-200 grain range. 158 grain at 1500 fps is cool. The keith, about 175 grains, at 1400 fps is even better. You have to use some sense about this, but I feel a lot better about hot loading the 357 magnum than I do ones like 45 colt. I wouldn't be surprised if some of my loads are running up around 40-45k psi. I will not share them, but the older reloading manuals can get you in the ballpark.

[USSR]

I've got a lot of .357's, but I shoot .38 Specials and .38 Special +P's out of them. If I want more power, I don't look for more velocity, I simply get out a .45.

Don

[454PB]

I forgot to mention that all the factory loaded 158 gr. loads I have chronographed in a 6" barrel were in the 1300 fps. range. My Bluedot load is 9.5 gr. behind a 158 gr. boolit for 1250 fps., excellent accuracy, and the fired cases fall from the cylinder. Seems like a good replacement for everyday shooting.

Another favorite is 13 gr. WC820 for 1250 to 1300 fps.

[fatelk]

I forgot to mention that all the factory loaded 158 gr. loads I have chronographed in a 6" barrel were in the 1300 fps. range. My Bluedot load is 9.5 gr. behind a 158 gr. boolit for 1250 fps., excellent accuracy, and the fired cases fall from the cylinder. Seems like a good replacement for everyday shooting.

Another favorite is 13 gr. WC820 for 1250 to 1300 fps.

This is the kind of load I want to end up with. With more than one .357 to test loads with, I should be able to come up with something that works well.

No need to hot load them for me. I have a couple Model 29s if I need something bigger.

I see that the Lyman 4th edition Cast Bullet Handbook list a universal receiver with a 4" barrel as the test gun. Given the lack of a cylinder gap, I wonder how comparable that would be with a 6" barrel revolver? The Hodgdon data lists some impressively high velocities, but they used a 10" barrel.

[Patrick L]

Yeah, 1300 or so is fairly easy to attain, and you are generally well within the realm of published, tested loads. I too prefer to keep my .357s on the softer side

I also never cease to be amazed at how many different factors will affect velocity readings in individual guns. I seem to have a "fast" Model 66 six inch. Over the years, it has consistently run 80 to 100 fps faster than the same ammo, both factory and reloads, in other .357s I have owned. And I'm going back all the way to the 90s. As I recall, I've owned two Model 28s (a four and a six) and a 27-2 six inch. The two 28s were pretty close, even with the difference in barrels, and the 27-2 is pretty close to what they used to generate. But that blasted 66 always ran faster. I realize I'm not giving specific numbers, I'd have to consult the records, and I'm not at my bench. But the premise remains. I recently acquired a 27-2 long tom, but I've not had the chance to chronograph anything through it yet. That's one of my summer projects. I'm really curious to see what kind of velocities it churns out.

[oso]

To make reasonably full use of the energy potential of the .357 Magnum I use my lever rifle. I wonder if I've put more rounds through that than my S&W 28 and Ruger Sec Six together. I do shoot more 38 Special but not in 357 mag chambers.

[Paul105]

Took my new Labradar out for a spin a while back. The 2 3/4" M66-8 seems to be one of those "fast" guns.


Labradar Muzzle Velocity (familiarization run)
60 Deg F
S&W M66-8 2.75" .357 Mag

130gr Fed Hydra-Shok JHP "Personal Defense" PD357HS2 H …….. 1,416 fps avg (84 fps ES) -- two rounds
140gr Underwood Xtreme Penetrator (Philips head mono metal).. 1,422 fps avg ( 5 fps ES) -- two rounds
158gr Horn Xtp - 15.0gr A2400 Std small pistol, new Starline...… 1,316 fps avg (49 fps ES) -- six rounds
165gr CSWCGC (358156) - 13.0gr A2400 New Starline ...… 1,180 fps avg (84 fps ES) -- six rounds
180gr Buff Bore …………………………………………………………………………….. 1,312 fps avg ( 6 fps ES) -- two rounds
185gr LFNGC (Beartooth), 15.0gr Lil'Gun, CCI 400 New Starline.. 1,228 fps avg (14 fps ES) – two rounds
200gr WLNGC (leadheads), 13.4gr H110, Fed 205, New Starline.. 1,102 fps avg ( 4 fps ES) – two rounds
200gr WLNGC (leadheads), 14.4gr H110, Fed 205, New Starline.. 1,155 fps avg ( 2 fps ES) – two rounds
(purported to be the “Doubletap” load info)
200gr WLNGC (leadheads) handload with Lil Gun ………………………. 1,266 fps avg ( 2 fps ES) -- two rounds
Load data not given -- maybe too much of a good thing. Spent cases fell from chambers, and no obvious signs of over pressure. Recoil was heavy. Don't even know if this stabilizes.

The 13.0gr A2400 is my 99 % use load. If even needed, I would limit useage of the 180, 185, and 200gr loads in J & K Frame guns

Also ran two Buff Bore 180s thru 16" Rossi M92 carbine ……………. 1,894 fps avg ( 6 fps ES) -- two rounds

Just some more data points.

FWIW,

Paul

[megasupermagnum]

Absolutely, small differences in barrel length are no guarantee that the longer one will be faster. I would think a 6" should be faster than a 2 3/4". My 4 5/8" blackhawk seems to be very similar to most 6" guns.

[fatelk]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

[dtknowles]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

When was the last time you checked your scale. Your velocities do seem low.

Tim

[fatelk]

When was the last time you checked your scale. Your velocities do seem low.

Tim

It may be time to retire the old Ohaus scale. I've been using it for 30 years. I just checked it against a couple extra scales that I have, and it's nearly 2/10gr heavy compared to the others, at 10gr, 25gr, and 50gr. Not sure why that could be, but I'm pretty sure that 2/10 of a grain wouldn't make anywhere near the kind of difference we're seeing.

[Forrest r]

Not all bullets are created equal, bullet design can make a load very as much as 70fps. A couple years back I did some head to head testing using these bullets along with 2 others not pictured and 5 different powders in a snubnosed 38spl.
https://i.imgur.com/0A0Ga7O.jpg

I wanted to develop a 357 load for a 586 l-comp. The l-comp has a 3" bbl shroud (full length ejector rod) and a 2 1/2" bbl with a comp in the last 1/2" of bbl shroud.
https://i.imgur.com/5vi2mrE.jpg

I chose the mihec 158gr fn hp for a test bullet (top picture top row 2nd from left/green). Decided to do a little head to head testing with 2400 vs h110 vs mp-300. Figured while I was at it might as well make up a bunch of hot/full house loads of each powder and do testing in different bbl length's while I was at it. So I loaded up a pile of reloads using the 3 different powders and that mihec bullet. For test firearms I used.

2 1/2" bbl (1 revolver)
4" bbl (2 revolvers)
6" bbl (2 revolvers)
8" bbl (1 revolver0
10" contender

At the end of the day I got:
2 1/2" bbl ='s 1200fps with 2400 and 1150+fps with h110 & mp-300
4" bbl ='s 1300+fps for all powders with the h110 & mp-300 starting to edge ahead/faster
6" bbl ='s 1450+fps with the h110 & mp-300 1400+fps with 2400
8" bbl ='s 1500fps+ with h110 & mp-300 1450+fps with 2400
10" bbl ='s 1600+fps with h110 & mp-300 1500+fps with 2400

That 8" bbl never did have good velocities, never bothered to replace it because I just don't use it that often.

Ended up using the fn/170gr version of that mihec bullet in the l-comp. Same load of 2400/same 1200fps out of that 2 1/2" bbl.
https://i.imgur.com/3f3FUJ4.jpg?1

[dvnv]

In working up loads for the "magnums" (K frames excluded), H110 has ended up the best performer when both velocity and accuracy is considered.
You probably already know this, but H110 accuracy is generally best when the loaded to the base of the bullet, maybe with just a smidge (technical term) of compression.

I save LilGun for the 218 Bee, where it also shines.

[Silver Jack Hammer]

I only cast 358421 when the government tells me to stay at home, but wouldn’t cast boolits at 1500 fps lead your bore? I’ve got a brace of seldom used Ruger 3 screw Blackhawk’s in .357 with 4 5/8” barrels.

[megasupermagnum]

I did some load testing today. I tried loads with H108, AA#9, H110, and 2400. It seems that both of my revolvers are on the "slow" side for velocity. Nearly all velocities were slower than book velocities for the same load. I realize that's not unusual.

From searching around, I found that 15.5gr H110 is a popular charge with a 158gr cast bullet. This clocked at about 1150fps in the 4" model 66, and 1250+ in the 6" 586. I can live with that. I wasn't really trying to wring out accuracy today, but did shoot a cylinder full at a bullseye 20 yards away, and got a nice 1.5" group. 1150 seems slow for a full-charge .357 load, seems more like a mid-range Unique load, but it is what it is. Unfortunately I don't have any factory ammo to test in that gun. I even wondered about my chronograph, so I broke out my spare. It was right on par with the other one.

The H108 was more consistent with velocity; 14.0gr was about 50fps faster in both guns than the H110. I didn't test it for accuracy. After getting home I was searching around online and found a warning to not use Winchester SPM primers with H108 as they could cause pressure spikes, and those were the exact primers I was using. I'll try some more with non-magnum primers.

That is not too surprising, 15.5 gr H110 is listed as a starting load. Most manuals I'm seeing show a max with a 158 grain at 17 grains. I have used Lil'Gun, before the internet told me how hot it burned. It works great. The reason I no longer use it, is that it is a twin to H110. Since most of my strong loads used H110, there is no reason to switch. I don't understand why Lil'gun exists at all. I'm sure there is somewhere it has an ever so slight advantage to h110, but in handguns, Lil'gun is a redundant powder. Another good one is Vhitavouri N110, and may even have a leg up on H110 in terms of speed. I always got better accuracy with H110. AA #9 has always been a rather mundane performer for me.

[MT Gianni]

If you want velocity you are shorting yourself by not trying MP300.

[fatelk]

Thanks everyone. You’ve given me lots to consider, and a few options to try.

My Lyman manual listed 15.9gr H110 as max for the most similar bullet I could see, but I wondered how much of the difference could be from the powder-coated Lee bullet I’m using. Maybe I’m just being too conservative with my load work up. I don’t want to push it too much, considering the K frame model 66, but in reality it doesn’t get shot much with .357 Magnums, mostly just .38s. Most of the magnums I load will be used in the 586, and even then I don’t shoot a lot of them.

One thing I saw than made me wonder about either a chronograph issue, or that the H110 was still a bit light, was the occasional low velocity with the H110 loads. With the 6” gun, I’d have some that would clock high 1200s/low 1300s, then one would clock 1090. That seemed odd.

[357Mag]

Fatelk -

Howdy !

My go to .357Mag load is: 14.5gr WW296 ( H 110 same stuff ) and SP Mag under a ( Lyman ) SWC of
158-172br. This was the minimum charge Winchester ( Olin ) recommended using this powder in
.357Mag.

It has always shot superbly in 4,5, and 6” “N”- frames, and in a Marlin 1894SC.


With regards,
357Mag

[megasupermagnum]

Thanks everyone. You’ve given me lots to consider, and a few options to try.

My Lyman manual listed 15.9gr H110 as max for the most similar bullet I could see, but I wondered how much of the difference could be from the powder-coated Lee bullet I’m using. Maybe I’m just being too conservative with my load work up. I don’t want to push it too much, considering the K frame model 66, but in reality it doesn’t get shot much with .357 Magnums, mostly just .38s. Most of the magnums I load will be used in the 586, and even then I don’t shoot a lot of them.

One thing I saw than made me wonder about either a chronograph issue, or that the H110 was still a bit light, was the occasional low velocity with the H110 loads. With the 6” gun, I’d have some that would clock high 1200s/low 1300s, then one would clock 1090. That seemed odd.

Are you using magnum primers? 15.5 is a good safe load, and should certainly not be seeing 200 fps velocity swings. I'm looking at the Lyman 50th manual, and for a 158 grain jacketed bullet they list 17 grains H110 as max. This is safe in any 357 magnum ever made. I wouldn't shoot 20,000 of them in a lighter gun for fear of wearing it out, but they are not dangerous. Whether or not this is the most accurate or not is not certain. I've found great accuracy over that maximum. I wish there was a SAMMI +p spec of say 45,000 psi.

[Silvercreek Farmer]

If you want velocity you are shorting yourself by not trying MP300.

+1 "Original" 357 mag specs are attainable with published data. Very accurate as well.

[Larry Gibson]

Keep in mind when making comparisons of your chronographed data with published data that the published data may be muzzle velocity. I most often test using the Oehler M43 with the start screen at 15' from the muzzle. It gives both screen velocity and muzzle velocity (based on screened velocity/ feet from muzzle/B.C. of the bullet). I have compared the corrected velocity using a MagnetoSpeed attached to the muzzle during the same test.

If you comparing your chronographed velocities with published data which may be and probably are muzzle velocities there can be a discrepancy simple because of the two different measurments on top of other variations. With the 357 magnum I found, with the same bullet [358156], chronographed velocities at 15' give 7 - 10 fps lower velocities at sub- sonic levels. When the bullet is pushed trans-sonic at about 1200 fps there is usually a 20+ fps difference between chronographed and muzzle velocity. When pushed to 1400 - 1500 + fps the difference can be as much as 40+ fps difference. .

[megasupermagnum]

Keep in mind when making comparisons of your chronographed data with published data that the published data may be muzzle velocity. I most often test using the Oehler M43 with the start screen at 15' from the muzzle. It gives both screen velocity and muzzle velocity (based on screened velocity/ feet from muzzle/B.C. of the bullet). I have compared the corrected velocity using a MagnetoSpeed attached to the muzzle during the same test.

If you comparing your chronographed velocities with published data which may be and probably are muzzle velocities there can be a discrepancy simple because of the two different measurments on top of other variations. With the 357 magnum I found, with the same bullet [358156], chronographed velocities at 15' give 7 - 10 fps lower velocities at sub- sonic levels. When the bullet is pushed trans-sonic at about 1200 fps there is usually a 20+ fps difference between chronographed and muzzle velocity. When pushed to 1400 - 1500 + fps the difference can be as much as 40+ fps difference. .

I knew it makes a huge difference with shotguns, I had no idea the effect was that great with bullets too. Most of my testing is done around 6'-8'.

[fatelk]

OK, I had a chance to get out again today. Here's what I came up with:
.357 Magnum- Lee 358-158-RF powder coated- RP brass- WSPM primers
S&W 586 6" barrel
16.0gr H110: 1287, 1353, 1373
16.5gr H110: 1305, 1412, 1401, 1388
17.0gr H110: 1395, 1332, 1370, 1303, 1366

S&W 66 4" barrel
16.5gr H110: 1225, 1203, 1223, 1279, 1205

I also loaded up some rounds with 14.0 and 14.5gr of H108, with standard primers (CCI500) instead of magnum. I only shot a couple across the chronograph when it started raining, so chronograph time was over. Velocities with these were low, around 1200fps. Anyone tinkered much with H108?

There were no sticky cases in any of these loads. I know that primer flattening is a generally unreliable indicator of pressure, but the WSPM primers always look flatter than the CCI 500s, no matter the load. Two of the 17.0gr H110 cases (fired in the 66) had primers that did look a little flatter than the others.
I also realized one issue that might be a factor in the inconsistent velocities; the brass I've been using is RP, but it's of unknown vintage, definitely not all 1x. Would that account for much?

One thing I did today that I'd never done before: I set up both chronographs in line with each other. They are both inexpensive so I've never known how much to rely on them for accuracy. The Caldwell unit read consistently 10-15 fps faster than the Chrony F1 a few feet behind it.

[derek45]

5" 686

17gr win296/H110

158xtp

1242fps.
---------------------------
17.3gr w296/h110

158xtp

1269fps.

17.2 w296/H110
LEE 158grSWC-GC ( closer to 168gr with lube & gas-check)
1489fps


22gr w296/H110
125gr rem SJHP
1639 fps

140grXTP
19.6gr w296/H110
1442fps ave.

---------------------------

14.7gr 2400
158 SWC
1275fps

15.8gr 2400
158 SWC
1364fps

https://i.imgur.com/sxpoT1D.jpg

https://i.imgur.com/NUvMR4H.jpg

https://i.imgur.com/HbqNBcf.jpg

[tazman]

OK, I had a chance to get out again today. Here's what I came up with:
.357 Magnum- Lee 358-158-RF powder coated- RP brass- WSPM primers
S&W 586 6" barrel
16.0gr H110: 1287, 1353, 1373
16.5gr H110: 1305, 1412, 1401, 1388
17.0gr H110: 1395, 1332, 1370, 1303, 1366

S&W 66 4" barrel
16.5gr H110: 1225, 1203, 1223, 1279, 1205

I also loaded up some rounds with 14.0 and 14.5gr of H108, with standard primers (CCI500) instead of magnum. I only shot a couple across the chronograph when it started raining, so chronograph time was over. Velocities with these were low, around 1200fps. Anyone tinkered much with H108?

There were no sticky cases in any of these loads. I know that primer flattening is a generally unreliable indicator of pressure, but the WSPM primers always look flatter than the CCI 500s, no matter the load. Two of the 17.0gr H110 cases (fired in the 66) had primers that did look a little flatter than the others.
I also realized one issue that might be a factor in the inconsistent velocities; the brass I've been using is RP, but it's of unknown vintage, definitely not all 1x. Would that account for much?

One thing I did today that I'd never done before: I set up both chronographs in line with each other. They are both inexpensive so I've never known how much to rely on them for accuracy. The Caldwell unit read consistently 10-15 fps faster than the Chrony F1 a few feet behind it.

I have read that when you start getting the same or slightly less velocity with H110/296 that you need to drop back to the last charge before the increase stopped. Supposedly, if you continue to increase charge weight, you run the risk of bad things happening.
It has been a long time since I saw that article. I can't remember where I read it.

[megasupermagnum]

Those velocity spreads are not great, but I've seen worse. Something as simple as changing primers could cut that down. You could try a CCI 550, Federal 200 etc. I've never tried H108. I know chronographs can disagree. I wouldn't sweat such a small difference. If you don't feel comfortable going any higher with the powder, I would try a different primer first. I know the brass can do it too, but when I had it happen, I could feel the differences when seating bullets. One would slip right in, and the next felt like I was resizing the case.

[megasupermagnum]

5" 686

17gr win296/H110

158xtp

1242fps.
---------------------------
17.3gr w296/h110

158xtp

1269fps.

17.2 w296/H110
LEE 158grSWC-GC ( closer to 168gr with lube & gas-check)
1489fps


22gr w296/H110
125gr rem SJHP
1639 fps

140grXTP
19.6gr w296/H110
1442fps ave.

---------------------------

14.7gr 2400
158 SWC
1275fps

15.8gr 2400
158 SWC
1364fps




Wow, you gained 220 FPS over a 158 grain XTP by going to an even heavier SWC! Something strange is going on. I know each gun is unique, but I was getting 1450 fps with a 158 grain jacketed bullet and 17gr H110, similar to your 1489 fps with 17.2gr H110. I believe the bullets I was using were Remington, but I've used XTP's as well. Something doesn't seem to add up to me, and I'm not sure what it is.

[fatelk]

I have read that when you start getting the same or slightly less velocity with H110/296 that you need to drop back to the last charge before the increase stopped. Supposedly, if you continue to increase charge weight, you run the risk of bad things happening.
It has been a long time since I saw that article. I can't remember where I read it.

Yes, I was thinking that 16.5gr looked like it might be a good place to settle. I'll do some more fiddling around, try some other primers maybe, try some loads in some new brass I've been saving. I'm about half tempted to buy a box of 158gr factory ammo to clock through my guns, just for curiosity.

Like I mentioned, my goal here isn't necessarily to maximize velocity. I just want to work up a good "magnum load", one that's a good, safe, full charge for this round and this bullet (in my guns). After this, I think I'll also work up a Blue Dot load that's a little lighter. I have several pounds of Blue Dot that I've been saving for just that purpose. Lighter than that, and I'll just shoot .38 specials, which is 90+% of what I shoot out of my .357s anyhow.

I was actually impressed by the consistency of my chronographs. I even wonder if part of the difference might have been due to the one being a few feet behind the other?
The Chrony is close to 20 years old, and the Calwell is one that I found in a trash can at the range! Someone had shot it, blew it apart with a huge hole in the side, battery compartment blown out, vaporized lead on circuit boards, wires blown apart inside, etc.
I took it home just for kicks, and realized that they had just barely missed all critical components. I cleaned circuit boards, soldered wires, put it back together as best I could. It looks like hell, but it works great!

[tazman]

Sounds like you've got a plan figured out.
Given how much velocity drops off right away, I think you may be right about one chrono being behind the other. Next time you test, switch the order of the chronos and see if that changes things the other way.

[derek45]

Wow, you gained 220 FPS over a 158 grain XTP by going to an even heavier SWC! Something strange is going on. I know each gun is unique, but I was getting 1450 fps with a 158 grain jacketed bullet and 17gr H110, similar to your 1489 fps with 17.2gr H110. I believe the bullets I was using were Remington, but I've used XTP's as well. Something doesn't seem to add up to me, and I'm not sure what it is.

Lead bullets are typically faster than jacketed.

.

[yeahbub]

My go-to powder for .357 has long been 2400, since I once bought a large lot. A cast 147gr 9mm swaged to .358 and GC'd over 15.5gr of 2400 does everything I need it to from a 20" carbine or a 6" wheelgun. The Chrony showed high1700's - low 1800's out of the carbine and high 1300's out of the 6". Still comfortable to shoot in the pistol, though. For hunting, I once worked up a Lilgun load of 16gr under a 180gr RNFP group buy mold which I paper patched for carbine use. It had a lot of thump which I intended for feral hog hunting, but there aren't any around here and the opportunity hasn't presented. I have them, though, and someday. . . .

[megasupermagnum]

Lead bullets are typically faster than jacketed.

.

Sure, but I have never seen a 220 FPS discrepancy. That is a HUGE difference, well beyond what can be attributed to friction.

[Silvercreek Farmer]

Sure, but I have never seen a 220 FPS discrepancy. That is a HUGE difference, well beyond what can be attributed to friction.

Seating depth differences can result in large pressure/velocity swings between different bullet profiles, even if the weight is the same.

[megasupermagnum]

Seating depth differences can result in large pressure/velocity swings between different bullet profiles, even if the weight is the same.

I've shot quite a bit of H110 in 357 magnum. 17 grains is near filled, if not a 100% filled case. I do not believe seating depth can account for over a 200 FPS difference, not with a full case of slow powder. I honestly do not know what is causing it, but I did not see this in my own testing. I've never seen such a difference in any caliber. Mabe a typo? 1422 fps seems more realistic.

[derek45]

I've shot quite a bit of H110 in 357 magnum. 17 grains is near filled, if not a 100% filled case. I do not believe seating depth can account for over a 200 FPS difference, not with a full case of slow powder. I honestly do not know what is causing it, but I did not see this in my own testing. I've never seen such a difference in any caliber. Mabe a typo? 1422 fps seems more realistic.

home from work, and looking over my paper logbook, it says - 6" 586 1489fps, so if it's a typo, I goofed it up while logging it. ( also a 6" vs 5" )

looked further, other pages

5" 686 1354

6" 686 1405

I think I still have some of this old batch, gas-checked with red's carnauba, loaded in bulk on my Dillon 650, I can chrony them again if you like.

Sadly,...I traded that 586 for a 629 and have regretted it, but I still have the Horvath Custom 5" 686, and a 4" GP100
.
.


https://i.imgur.com/fNn1MjK.jpg

https://i.imgur.com/E4a1CN8.jpg

[megasupermagnum]

I don't doubt your cast bullet load at all. 1489 fps is right in line with what I've seen myself. It is the following load I am questioning.

17.3gr w296/h110
158xtp
1269fps.

Nearly the same load. 0.1 grains more powder than your cast load (that you admit is slightly heavier at about 168 grain), but replaced with a jacketed 158 grain XTP bullet. I don't see how you lost 220 FPS by going to a lighter bullet, even if it is jacketed. I'm not saying your wrong, just that something doesn't add up.

[Forrest r]

I don't doubt your cast bullet load at all. 1489 fps is right in line with what I've seen myself. It is the following load I am questioning.

17.3gr w296/h110
158xtp
1269fps.

Nearly the same load. 0.1 grains more powder than your cast load (that you admit is slightly heavier at about 168 grain), but replaced with a jacketed 158 grain XTP bullet. I don't see how you lost 220 FPS by going to a lighter bullet, even if it is jacketed. I'm not saying your wrong, just that something doesn't add up.


I've run into this^^^^ before.

It was a combo of brass with a lot of reloads under their belt and using a lyman m-die expander. Anymore I use factory expanders for jacketed and either m-dies or custom expanders for lead. Switched to a factory expander and the velocities went up with the jacketed bullets.

Don't know if this is what's going on with derek 45, not defending him but I've read his posts on different websites for years. His practices are sound, he always give good reports & his posts have always had real world results.

FWIW:
I'm at +/- 1450fps with my 158gr cast bullets also in 3 different 357's with 6" bbl.'s.

[megasupermagnum]

I trust him. I'm trying to understand the "why".

[ACC]

I've reloaded .357 Magnum for a long time, but have always wondered about velocities. A long time ago when I started, I remember reading that "the standard" for the .357 Magnum was a 158gr bullet at 1500 fps. That seemed excessive and I never was able to find a safe load that even came close, except back when I had my Dan Wesson with the 15" barrel (sure wish I had kept that one).

Over time I realized the effect of barrel length, and the fact that advertised ballistics are often not realistic. I came to the conclusion that 1300 fps in a 6" barrel wasn't that bad.

So, I'm getting ready to load up a bunch of .357mag. I have a bunch of brass prepped, and hundreds of Lee 358-158-RF bullets cast and powder coated, a batch that should last several years. I'm now revisiting an ideal load before loading them up. I have some AA #9, some H108, some 2400, and some H110. Of course accuracy is most important, but for velocity I'd like a load that is near the upper end while safe for S&W revolvers. Yes, I know that velocity isn't everything; I just want a realistic expectation for a good load.

Any thoughts or experiences along these lines?

With 22 grains of H-110 behind the Lee 158 gr RNFP out of my NM Blackhawk I can get just over 1300 FPS with it's 4 3/8 inch barrel with no pressure signs. Easy extraction, no flattened primers. One thing I have noticed though is that I have short case life. I only get about 5 reloads out of starline brass before it cracks at the neck. I have killed 5 feral hogs in the 150 pound range, at at least 6 feral dogs. All with this load.

ACC

[megasupermagnum]

With 22 grains of H-110 behind the Lee 158 gr RNFP out of my NM Blackhawk I can get just over 1300 FPS with it's 4 3/8 inch barrel with no pressure signs. Easy extraction, no flattened primers. One thing I have noticed though is that I have short case life. I only get about 5 reloads out of starline brass before it cracks at the neck. I have killed 5 feral hogs in the 150 pound range, at at least 6 feral dogs. All with this load.

ACC

22 grains H110 fit? And only did 1300 fps?

Well you guys convinced me to buy a 357 magnum, although it doesn't take much of a push. As sad as it is, I have not owned one since I feel in love with the 327 federal. I'll be picking up the 5" GP100 tomorrow. I have some 158 grain XTP's stashed somewhere, and cast some Keith bullets today.

[AnthonyB]

I am a big fan of the 357 Magnum. It is completely different cartridge from a M92 rifle. But I but will go to a 44 Special if I need more than a 173 gr Keith at 1200 fps from a handgun. If the 44 Special won't do it, I need a 30-06.
Tony

[megasupermagnum]

I am a big fan of the 357 Magnum. It is completely different cartridge from a M92 rifle. But I but will go to a 44 Special if I need more than a 173 gr Keith at 1200 fps from a handgun. If the 44 Special won't do it, I need a 30-06.
Tony

10 years ago you didn't even hear about 44 special. Now it is suddenly more powerful than 357 magnum? I don't mean that in any disrespectful way, it just seems strange to me that so many different people on this board are so into the 44 special all of a sudden. It is a great cartridge, it doesn't need to be a magnum.

[derek45]

10 years ago you didn't even hear about 44 special. Now it is suddenly more powerful than 357 magnum? I don't mean that in any disrespectful way, it just seems strange to me that so many different people on this board are so into the 44 special all of a sudden. It is a great cartridge, it doesn't need to be a magnum.

because amazon is selling this again ....

https://www.amazon.com/dp/B00GDR4MVW/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1

https://m.media-amazon.com/images/I/51X4rQ8sTsL._SY346_.jpg

[megasupermagnum]

because amazon is selling this again ....

https://www.amazon.com/dp/B00GDR4MVW/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1

https://m.media-amazon.com/images/I/51X4rQ8sTsL._SY346_.jpg

Well, I guess that's not a bad thing.

[DHDeal]

Not that I'm suggesting you should spend the extra money, but if you want to see what is possible with a 357, get a FA83. The only weak link will be the brass. I've not quite gone as far as Taffin did in his article on the Freedom Arms 353 (same as the current FA83 357 Magnum), but I've been close. Until I got my MP GCHP Hammer mold, the lightest bullets I shot were 175 grains. The MP's are 158 grains and I haven't chronographed them, but above book max with H110 the fired cases tend to fall out when you tilt the revolver up.

They are big, heavy, expensive, and hold only 5 rounds but few things in life are worth what you have to pay for them. These revolvers are worth it. Consider it a bigger hammer driving the same nail.

[megasupermagnum]

There is so much meat on the cylinder of the 6 shot blackhawk, I can't imagine improving on that. As it is, I feel 100% confident the still plenty thick GP100 is as strong as they need to be. I don't like to load to the point brass sticks, but a little over max does not scare me.

[Silvercreek Farmer]

Not that I'm suggesting you should spend the extra money, but if you want to see what is possible with a 357, get a FA83. The only weak link will be the brass. I've not quite gone as far as Taffin did in his article on the Freedom Arms 353 (same as the current FA83 357 Magnum), but I've been close. Until I got my MP GCHP Hammer mold, the lightest bullets I shot were 175 grains. The MP's are 158 grains and I haven't chronographed them, but above book max with H110 the fired cases tend to fall out when you tilt the revolver up.

They are big, heavy, expensive, and hold only 5 rounds but few things in life are worth what you have to pay for them. These revolvers are worth it. Consider it a bigger hammer driving the same nail.

I've got no interest in one, but I do find it interesting to see what can be done...

http://www.sixguns.com/tests/tt353.htm

[AnthonyB]

I don't think the 44 Special is more "powerful" than a 357 Magnum. It just goes about the task a little differently. Bigger bullet with more weight at close to the same speed, without the earsplitting noise. The 45 Colt is a little more of the same thing. I just haven't seen the need for more velocity from a handgun. A 38 173 gr. SWC at 1200 fps has completely penetrated everything I have shot with it, and a 44 250ish SWC has done the same from the Special at 1000 fps or so.
Tony

[megasupermagnum]

I don't think the 44 Special is more "powerful" than a 357 Magnum. It just goes about the task a little differently. Bigger bullet with more weight at close to the same speed, without the earsplitting noise. The 45 Colt is a little more of the same thing. I just haven't seen the need for more velocity from a handgun. A 38 173 gr. SWC at 1200 fps has completely penetrated everything I have shot with it, and a 44 250ish SWC has done the same from the Special at 1000 fps or so.
Tony

For the record, my all time favorite semi auto handgun cartridge is the 45 acp. I was into the 10mm auto, but found that what little extra power it had, was offset by the heavy guns for it. I never even got into the 45 super. This has now changed, and light guns in 10mm are out there, but I still like my 45.

The key difference is that a semi auto is limited by what will fit and feed in the gun. A revolver is not. Diameter is a big advantage in a semi auto. It is not as much in a revolver. Different strokes for different folks, I always found a lighter bullet at higher velocity was more enjoyable to shoot than a heavier bullet at lower velocity, even if both equal out to about the same effectiveness. The cost of speed is muzzle blast, but I have never found 357 magnum to be bad at all. Decibels don't tell the whole story. I would say a 22 lr to a 44 special is a huge step in noise, 44 sp to 357 mag is a small step, and 357 mag to something like 7-08 (in a handgun) is a big step.

[AnthonyB]

We have found common ground! The 45 ACP is my all time favorite pistol cartridge. Enough power without objectionable recoil, and you can get them from tiny to 1911 size. My personal favorite now is the M&P Shield with an Apex trigger installed, but the Sig 220 and Dan Wesson 1911 are high on the list. I have almost 40 45 caliber moulds but could live happily with the RCBS 45-230 CM and 6.0 gr. Unique.
Tony

[megasupermagnum]

The new Lipsey's special is home. Another great Ruger, they never fail. 6 perfect .358" throats, a consistent .348" bore with zero constriction at all. The barrel to cylinder gap is a little wide at .007", but that is no concern to me. Trigger is fantastic, and another beautiful set of wood grips with wood grain. They are lighter in color than the 327 federal, but just as pretty.

357 magnum on right
261029

357 magnum on left
261030

[Wheelguns 1961]

Congratulations! It seems like we have the same taste. I got one of the 327 gp100’s, and was impressed enough to pick up a 357 model a couple of months later. They are both good shooters. I think your grips look better than mine.

[megasupermagnum]

Congratulations! It seems like we have the same taste. I got one of the 327 gp100’s, and was impressed enough to pick up a 357 model a couple of months later. They are both good shooters. I think your grips look better than mine.

The flash kind of throws it off. The 357 shows up decent, but the 327 wood is not that rich in real life. I honestly think this is the best handgun Ruger has ever made. I've been begging for a 41 magnum version since they came out.

[Outpost75]

Adding to what Larry Gibson said, for years published velocities for .357 have been those obtained from solid industrial test barrels and not revolvers. After about 1980 .357 police service loads were tested using a 4-inch "vented" test barrel which was a two-piece affair having separate chamber and barrel sections mechanically assembled to produce a standard 0.008" gap between the two sections which simulated revolver performance.

While the 4-inch vented test barrel is still used occasionally, so is also the solid test barrel, which gives higher velocities. Some of the powder manufacturers use barrels of 7 inches or longer which produce velocities which are entirely unrealistic to compare with revolvers we would normally carry for field use.

Apples and oranges. Read the fine print.

Velocities of older .357 ammo fired from 4-inch and 5-inch revolvers:

Factory .38 Special +P and .357 Mag. Velocities and .38 Special (.38-44) Handloads
Ammunition____________________S&W Model 28 4”____Colt New Service .357 Mag. 5”

1950s Vintage Factory Loads for Reference:

.357 Mag. Super-X 158-gr.Lubaloy__1236, 8 Sd _______________1307 fps, 36 Sd
.357 Mag. Rem-UMC 158-gr. SWC___1221 fps, 23 Sd___________1287 fps, 27 Sd

261197261198

[fatelk]

I got out again today with the chronograph. I tested a bunch more, with virgin Winchester brass and a couple different primers.

One of the things I've always had trouble with, when working up a good load, is pressure signs. All of the empties of all the loads dropped out of the chambers freely and easily. A couple of the Winchester primers looked flatter than they should be, but all of the CCI primers looked fine.

Lee 358-158-RF powder coated
H110 16.5gr WSPM primers
6" barrel velocity- 1348, 1321, 1349
4" barrel velocity- 1188, 1233, 1226

H110 16.5 CCI550 primers
6" velocity- 1378, 1374
4" velocity- 1276, 1247, 1240

H108 15.0gr CCI500 primers
6"- 1380, 1368
4"- 1274

H108 15.5gr CCI500
6"- 1405, 1396
4"- 1293

2400 15.0gr CCI500
6"- 1365, 1381
4"- 1267

I shot a few more, but those are representative. Velocities are good, but I think I'll back off some and test for accuracy now. I don't need to ride the top edge for horsepower. Factory velocity is good enough. I kind of like the looks of the H108 loads.

I also shot a few rounds out of my old Model 29 .44 Mag, some "mid-range" Unique loads with powder coated 429421s. They clocked 1100fps from a 3" barrel. I guess I really don't need maximum horsepower from .357 loads.

[DHDeal]

Probably not. I find the best accuracy just shy of "a grain to far". I suppose what I'm trying to say is accuracy is found for me at a pressure level not necessarily a velocity level. I can sling a bullet faster with H110 than HS6, but both powders can turn in similar accuracy at a given pressure level. Now I don't have a scientific lab here, but the chronograph, manuals, and the target give me clues I'm probably not wrong on this at least.

[megasupermagnum]

I got to try the new 5" barrel GP100 today. I only had one load, my gold standard of a keith bullet with 10 grains bluedot. It went 1220 fps as measured from 8'. The bullet was 175 grains.

If all you are looking for is 1200-1250 fps with a 158 grain, there are a whole pile of powders that will work great. H110 can, but doesn't always work the best at the lower levels. Bluedot would be the one to try for sure, although 2400, 800x, HS6 would be great choices as well. Even Unique would likely be a good choice. I've never tried H108, but I have heard good things.

You guys convinced me to buy a pound of 300-MP. I never realized it had the potential for more velocity than H110, but it sure looks good on paper. You know how that goes.

[fatelk]

Here's a question for you all, but especially Larry, since he's the go-to guy with the pressure testing means:

When working up a non-book load, how to really know when you're within proper pressure limits, other than extrapolating from similar book loads and velocity measurements?

For example, I can't find any book loads for this particular Lee bullet and H110/296 powder. I can't find any relevant data for H108 powder, other than that it's basically WC820/AA#9, and generally slightly slower than #9. My test loads and measured velocities tend to support this, at least for the 8lb jug that I have.

I've loaded up H108 loads definitely on the hot side, that clocked 1450fps out of my 6" 586. The primers were not flattened, and the brass dropped easily from the chambers. I assume they are over pressure but I have no way of knowing for sure, as they don't show it. Any thoughts?

My plan at this point is to back off the H108 until they're around 1300fps, and shoot accurately (if they shoot accurately, that's what's important). My feeling is that that should be a good, safe "standard magnum" load, for these components. My only hesitation is in not knowing what the pressure levels are. I would just be going off the assumption that since there were no real danger signs at 1450fps, 1300fps should be safe enough.

[megasupermagnum]

There is no guaranteed way to know without pressure testing equipment. Primers are a poor indicator, but they are an indicator. Federal primers will be one of the first to flatten, CCI one of the last. It could be 30k, 40k, 50k psi, maybe higher. One of the reasons I like to play with the magnum handguns, is that even if the pressure is over spec, it is not the end of the world. Load a 44 special 5,000 PSI over some of the hot loads out there, and who knows what might happen. I'm not saying to be reckless at all, but if you are comparing as much load data as you can, not seeing any pressure signs in the gun (sticking brass, flat primers, primer pockets loose, extruded brass, etc.) then I would not worry one bit. Accuracy is king, and I find it is many times on the strong side.

[USSR]

Reading primers for pressure signs in a bottleneck rifle cartridge is all well and good, but for the most part it don't work that way with handgun rounds.

Don

[fatelk]

I'm not saying to be reckless at all, but if you are comparing as much load data as you can, not seeing any pressure signs in the gun (sticking brass, flat primers, primer pockets loose, extruded brass, etc.) then I would not worry one bit.

Thanks, that's what I was thinking, especially since I'll be backing off from what I worked up to. For the record, I've been using surplus powder off and on for literally decades. I've always done just this when working up loads; extrapolating from book loads and watching velocity, kind of seat of the pants sort of thing. I've always wanted to be as scientific about it as possible.

Now I've got all this time at home, and this is just a project to tinker with. I'll sure be glad when this crazy time is over and I'm back to work full time. I love spending time with my family, and I love taking time off of work, but this is getting ridiculous.

[megasupermagnum]

Reading primers for pressure signs in a bottleneck rifle cartridge is all well and good, but for the most part it don't work that way with handgun rounds.

Don

It does seem to be more valid in many bottleneck cartridges, as most of them have pressure specs just below where brass cases start to stick, extrude, etc. That doesn't mean there are no pressure signs in a magnum handgun. Certainly if your primer pockets are loose, you are WAY over the limit. Sticky cases often times is a rough chamber, but could be a sign. I wouldn't be surprised if Federal small pistol primers are flattening before 40,000 PSI. It certainly seems that way with cartridges like 327 federal (45k MAP). Federal primers seem to flatten out near max loads in 357 magnum, even following data to a T, using the exact bullet. I think the key is to compare to factory ammo, look at the signs as a whole, a chronograph can help, and with data to compare to, you can certainly be safe.

Pressure testing equipment is out there that isn't stupid expensive. The Pressure Trace II system is $600. Even though I have it, I'm not rushing out to pressure test all my handgun ammo. I use it for shotguns, where no reliable pressure signs exist, and a primer change can move a load from mild to out of control. These problems do not exist in 357 magnum. If H&R were still selling barrels, I would be pressure testing more.

[fatelk]

Reading primers for pressure signs in a bottleneck rifle cartridge is all well and good, but for the most part it don't work that way with handgun rounds.

Don

I understand, especially with lower pressure handgun rounds.

Here are some CCI 500 primers from a couple different loads. The two on the right were with 9.0gr of Blue Dot, velocity was pretty low. The four on the left were with a hot load of H108 (too hot, I suspect), that clocked 1450 fps in a 6" barrel. You can see a difference if you look, but it's not terribly obvious.

261211

[fatelk]

Thanks again everyone, for a very informative thread.

I've got my load now. I've settled on a charge of H108 that produces a consistent 1300fps in the 6" 586, and 1200fps in the 4" 66. The empties drop from the cylinders like light 38s, with no sign at all of excessive pressure. I'm very comfortable with this. I don't want to beat up my S&W revolvers.

As to accuracy, I shot several 6-shot groups through each revolver, at 25 yards. The worst group was 2.5". The best was 1.5". The model 66 seems just a touch more accurate. When I shot very carefully off sandbags, the worst group for either was right at 2", which is really about the best I can shoot, on a good day.

Yep, I think I've found just what I was looking for.

[megasupermagnum]

I understand, especially with lower pressure handgun rounds.

Here are some CCI 500 primers from a couple different loads. The two on the right were with 9.0gr of Blue Dot, velocity was pretty low. The four on the left were with a hot load of H108 (too hot, I suspect), that clocked 1450 fps in a 6" barrel. You can see a difference if you look, but it's not terribly obvious.

261211

These primers show a large difference. Not in flattening, but the left ones are clearly cratered. Cratering can be a pressure sign. Some guns show cratering with nearly all loads, it just depends on the firing pin hole. The best way is to compare to a factory load. If the factory load also shows cratering, then you may be ok.

It looks like you are happy with H108. That should be a decent midrange load that you can shoot day to day. I don't like shooting the full power stuff all the time myself.

[fatelk]

I did notice that, and I figured those loads were too hot. I felt that was pushing too hard. The load I shot today doesn't show that. Under a magnifying glass, 2 or 3 out of a box of 50 empties have a tiny amount, but the rest look fine, no cratering at all.

I realize I could get a little more horsepower with H110, or especially Lilgun or 300-MP, especially if I had Rugers, but my goal was an accurate load, safe for S&Ws, and comparable in velocity with most full-power 158gr .357 Magnum factory ammo. I think I have that now. It's been a fun project. Under normal conditions I wouldn't have had time for this, but right now I'm "working from home" about half the time, and it's been good to have something to keep my mind off worries of the future.

[dtknowles]

I understand, especially with lower pressure handgun rounds.

Here are some CCI 500 primers from a couple different loads. The two on the right were with 9.0gr of Blue Dot, velocity was pretty low. The four on the left were with a hot load of H108 (too hot, I suspect), that clocked 1450 fps in a 6" barrel. You can see a difference if you look, but it's not terribly obvious.

261211

It looks like some of the firing pin strikes are off center. That could be a timing issue.

Tim

[fatelk]

It looks like some of the firing pin strikes are off center. That could be a timing issue.

Tim

Just looking at other empties I have laying around, from other guns, they're not really worse than average. I think it just looks that way because the photo is magnified up close, and they're out of the brass. Would an out-of-time revolver shoot 1.5" groups @25 yards? :)

[megasupermagnum]

No, you can't tell timing problems by looking at spent primers. More than likely the firing pin is either high or low just a tiny bit. I think it is more rare to find one that is perfectly centered, than off a hair.

[fatelk]

It looks like you are happy with H108. That should be a decent midrange load that you can shoot day to day. I don't like shooting the full power stuff all the time myself.

I have one last question, in regards to this statement. What I've wanted was a full-power load that's safe for S&W revolvers, that won't beat up a K-frame with occasional use. In that context, I felt that I had a full power load, yet you call it "mid-range". Is that just in comparison to "megasupermagnum" loads for Rugers only, or would you push this load hotter, in these guns? It's a sincere question; I really appreciate all your input in this thread.

[megasupermagnum]

I have one last question, in regards to this statement. What I've wanted was a full-power load that's safe for S&W revolvers, that won't beat up a K-frame with occasional use. In that context, I felt that I had a full power load, yet you call it "mid-range". Is that just in comparison to "megasupermagnum" loads for Rugers only, or would you push this load hotter, in these guns? It's a sincere question; I really appreciate all your input in this thread.

I saw 1200 fps, I didn't realize that was the 4" gun. What you have could certainly be considered full power. It's just a word anyway with no real definition.

I don't know that I would sacrifice accuracy for power. If your gun shoots best at whatever charge of H108, that's the load to use.

[fatelk]

Cool, thank you. I know I reached this load in a somewhat backwards manner- working up a desired velocity first and then accuracy- but it did seem to work. All in all, I think it will work well. I wish I had been able to find better load data for H108, but everything I could find was that it was essentially the same powder as AA#9, but a tad slower. My velocities seem to bear that out, as this load is over maximum for AA#9 as far as charge weight, but right on for velocity.

[dtknowles]

No, you can't tell timing problems by looking at spent primers. More than likely the firing pin is either high or low just a tiny bit. I think it is more rare to find one that is perfectly centered, than off a hair.

Yes, and yes to the previous post. It is hard to tell with just the primers but with the shells still in the cylinder you can tell high/low primer strikes vs. random. I was saying it might be out of time because some are centered and some are not. If the timing was perfect they would all be offset the same amount. High, low, left or right. Good timing they would all be the same not some centered and some offset.

Tim

[fatelk]

I was saying it might be out of time because some are centered and some are not.

Now I understand! Would it help if I told you that those primers in that photo were fired in two different guns? :)

[dtknowles]

Now I understand! Would it help if I told you that those primers in that photo were fired in two different guns? :)

I almost asked that question. That could explain it.

Tim

[fatelk]

I've been shooting the old 586 for a while now, with this load. I'm pretty happy with the accuracy. It's been pretty consistent with around 3" 6-shot groups at 50 yards. That's really pushing the limits of my eyes and abilities, so I'm not going to complain about that.