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pt4u2nv
01-02-2010, 09:46 AM
OK, been working to get my boolits just where I think I need them with alot of help from you guys and finally got to load some and shoot em. Problem is it appears I am getting signs of high pressure that worries me quite a bit. Here are the details.

Winchester Brass ( probably fired 2 -3 times
Fed 100 Primer
AA#7 Powder ( Started at 7.6 grs, went to 8.3 at .1 gr increments)
177 gr cast boolit ( actual weight ) from RCBS mold # 82067
BHN is approx 10.4
COL 1.130
Bore slugged at .403
Cast boolit sized at .405
Chrony did not work well so I do not have FPS ( too frigin cold )

Anyway , the primers appear to be flattening even at the starting load of 7.6 and continues the whole way thru the 8.3 load. Not any worse from begininning to end. When I went to reload the next batch with the load that appeared to shoot the most accurate ( 7.7 grs ) 2 of the ( 50 ) cases split wide open on the sides, from top to bottom, which I luckly caught after the bullets were seated and complete. (I use a progressive press so don't see them till they are done.) What am I doing wrong and how do I fix it ? I have been loading for over 25 years ( although new to casting ) and have never seen this before , I was seating a bit deeper on prior loads and thought maybe that was the problem so I seated them out a bit from 1.120( recommended) to 1.130 thinking that would help but to no avail. I am reading some accounts that the .40 is a caliber to be careful with on pressure issues but I never dreamed it would be this fussy. Any insite on this would be appreciated.

Echo
01-02-2010, 11:50 AM
I believe Fed primers are known for being soft (I believe Lee advises against their use in their priming system), so that may be the cause of your flattened primers.

And for a case (or TWO!) to split that way after only 2-3 reloadings indicates excessive re-sizing, to me. Were the cases new, or once-fired, when you obtained them, or were they factory rounds you fired yourself? If your chamber is at the high end of tolerance, and your sizing die is at the low end, the brass gets worked too much, work-hardens, and splits.

Meine zwei pfennig...

pt4u2nv
01-02-2010, 12:31 PM
The brass was new when I started. I loaded them about 3 times max. As for the sizing die it is an RCBS Carbide 40/10MM that I have been using for years on my 10MM. with no issues at all. Of course it was with a different pistol, the 40 I am shooting now is a S & W Sigma. This just does not make sense to me at all !!!! The head stamping on the brass is also starting to fade out...again in my mind a hint of too much pressure. I am going to stop loading cast for now until I figure this out. I am going to try some Hornady XTP's to maybe eliminate any issues with the cast boolits and see if they show the same pressure issues. I just assumed it was the cast since I never had this before in any other handgun. I just started using my own cast boolits with the 40...so it is new to me, along with the 40.

sst04
01-02-2010, 12:39 PM
Too much Crimp???

Jayhem
01-02-2010, 01:33 PM
Yea I was going to ask about how much crimping you were doing. On my 40 I have to crimp the mouth of the case to .421-.422 in order for my cast reloads to cycle. I'm using 5.5 gr. of WSF and so far so good. I'm using 175 gr Lee TC boolits and my OAL is 1.120

Rico1950
01-02-2010, 02:39 PM
Pt4u2nv,
Assuming you have no leading issues, you can do a number of things.
Try another primer.
Back down on powder charge. All guns are different. If it is in fact a pressure issue your chrono will tell you.
Shooting the j word should show no signs of pressure with that load. the j bullets are .005" smaller than your .405" boolits.
I hope you double checked your powder weight. They can vary.

mpmarty
01-02-2010, 02:54 PM
Have you used the same load for j boolits? When you started loading cast did you find you had to suddenly increase the amount of belling on the case mouth? Excess belling and subsequent crimping can start a small crack in the mouth that would "creep" deeper into the case as it progressed.

pt4u2nv
01-02-2010, 05:15 PM
Have you used the same load for j boolits? When you started loading cast did you find you had to suddenly increase the amount of belling on the case mouth? Excess belling and subsequent crimping can start a small crack in the mouth that would "creep" deeper into the case as it progressed.

Yes, I did have to bell the mouth more with the cast. I was also wondering if that was causing the split in the case.

pt4u2nv
01-02-2010, 05:16 PM
Too much Crimp???

That is possible....I will load a few up backing off on the crimp and see if that helps too.

pt4u2nv
01-02-2010, 05:22 PM
Pt4u2nv,
Assuming you have no leading issues, you can do a number of things.
Try another primer.
Back down on powder charge. All guns are different. If it is in fact a pressure issue your chrono will tell you.
Shooting the j word should show no signs of pressure with that load. the j bullets are .005" smaller than your .405" boolits.
I hope you double checked your powder weight. They can vary.

That is on my list of things to try also since you mentioned it.I actually have been really careful with the powder weights so I am sure that is not the issue. Backing off a little sounds like a good idea also. I will have to try one thing at a time to try to isolate what the issue is.

I did go back on some records I kept and forgot that I did load a few j bullets a month or so ago and looks like I had the same primer issue with the j bullets 8.7 grs to 9.5 grs of AA#7 under 180 GDHP's.

MtGun44
01-02-2010, 05:32 PM
Make sure your boolits are not getting seated deeper in the cases as they
run up the feed ramp. This will raise pressures, and in a high pressure round
like the 40, likely to dangerous levels.

What gun? Glocks are known to have some issues with handloaded lead boolit ammo,
LOTS of them have been blown up. Some say that they know exactly why this
happens, I certainly claim no expertise in the area other than to note that I
have one friend, a very experienced rifle reloader that blew up his Glock,
then replaced the barrel with a Bar-Sto and has had no trouble since.

Any time the gun is telling you that the pressures are high - back off the powder
as the first thing. If you find out there was some other issue, you can slowly go
back to the load you want. A chrono is one of the best ways to control pressure.

If X amount of Such-and-So Powder is supposed to make 1100 fps with a certain
boolit weight and is making 1250 in your gun you can be absolutely certain that
your load is producing a bunch more pressure than the test gun, for whatever
reason isn't particularly important. Back off the powder until you get 1100 fps
over the chrono and you will be OK (assuming similar barrel lengths). If the
test barrel is 8 inches and your 3.5" minigun is getting the same as published
velocity - you are at a higher pressure for sure.

Bill

243winxb
01-02-2010, 05:40 PM
I would slug the bore again, if you get .403", i would size to .403"

The Double D
01-02-2010, 06:04 PM
Shot 2-3 timez or shot probably 2 or 3 times.... full lengthe resized? were the case ever annealed?

Doesn't sound like hot loads to me, sounds like work harden cases.

sagamore-one
01-02-2010, 06:18 PM
Let me throw a couple more possibilities in your direction.
First , you could have an over size chamber thus allowing the brass to expand more upon firing. Would be more apparent using cast as cast seals the bore better.
Second, you may have a weakened recoil spring allowing the barrel to move to the unlock position quicker, thus rupturing cases. I had a 40 Star that ruptured cases , even factory ammo, till a fresh recoil spring was installed.
I size my 40 boolits .401. .405 may be a bit large for that particular bore.
Just food for thought.

johnlaw484
01-02-2010, 09:02 PM
Glocks don't like reloads because a bottom portion of the case is unsupported and we all know that with each reload the case becomes weaker.

CWME
01-02-2010, 10:00 PM
First question, WHERE DID YOU GET A .405 sizer??? Only sizes I can find commercially for a .40 cal are .401.
Are you sure your barrel needs a .405 bullet?? That is .004 larger than normal. I would size them to .401 and see if you still get pressure and then worry about leading. This too me sounds like an issue of too large a bullet spiking the chamber pressures before the bullet is sized in the throat and starts down the barrel.

I have been shooting my Glock 22 with reloads for 7 years now with no issues. Both stock barrel and Wolf aftermarkets for lead. Would suspect hot rodding to be the culprit 99% of the time with Glock issues.

Echo
01-03-2010, 03:18 AM
Let me throw a couple more possibilities in your direction.
First , you could have an over size chamber thus allowing the brass to expand more upon firing. Would be more apparent using cast as cast seals the bore better.



My thought too. What is the diameter of the newly-fired case? Do you notice resizing taking more muscle than usual?

afrance
01-03-2010, 10:02 AM
I did go back on some records I kept and forgot that I did load a few j bullets a month or so ago and looks like I had the same primer issue with the j bullets 8.7 grs to 9.5 grs of AA#7 under 180 GDHP's.

If your notes are accurate with this information you overcharged these loads by 1.0 full grain according to Accurate Powders website. Gold Dots and XTPs are typically similar (large hollowpoint, deeply seated compared to traditional designs).

On page 5 of the free PDF the 180 gr XTP start charge for AA#7 is 7.7 gr and max charge is 8.5 gr ~34,600 PSI. Not sure what pressure was reached but it probably was closer to rifle pressures (50K+) and explains the faded headstamp and primer flattening.

Alan

truckmsl
01-03-2010, 04:23 PM
I've shot many 10's of thousands of cast boolits through my glock 23 (.40 cal) with Lone Wolf barrel. My experience is that harder boolits work better in a .40 auto loader, and target loads work better than full power. With target loads, there seems to be almost no limit to how many reloads the brass will take. My sense is that you're pushing too fast with too soft of a boolit. All of mine get sized to .401, and leading of the barrel is never an issue. .40 S&W is a very high pressure round, and you're asking a lot of your soft lead.

TAWILDCATT
01-03-2010, 08:24 PM
thats why I like the 1911 in 45 acp.I dont want any pistol running 35/40 lb pressure.and to many new shooters are getting 40s.you others are replacing the barrels to shoot lead.you know the glock is not good with reloads.I have seen the pictures of blown glocks.:coffee:

pt4u2nv
01-04-2010, 07:25 AM
If your notes are accurate with this information you overcharged these loads by 1.0 full grain according to Accurate Powders website. Gold Dots and XTPs are typically similar (large hollowpoint, deeply seated compared to traditional designs).

On page 5 of the free PDF the 180 gr XTP start charge for AA#7 is 7.7 gr and max charge is 8.5 gr ~34,600 PSI. Not sure what pressure was reached but it probably was closer to rifle pressures (50K+) and explains the faded headstamp and primer flattening.

Alan

Interesting...... Page 536 of Speers Number 12 Manual says 8.7 min, 9.7 max on AA#7 for the Speer 180gr GDHP. I looked up Accurates data after you said this and I agree the Accurate Manual that you stated is 7.7 to 8.5...What goes here ???!!!!Kinda dangerous if you ask me, wonder who is right. Chrony records from back then do show 1200 FPS avg. which is high after looking at it a little closer compared to approx 972 in Speers book. I had been having trouble with my old Chrony not working right and just assumed I was getting high readings unfounded.....should have trusted what I was getting by the looks of it. I never got the chance to check the cast boolits, I am betting they will be high also.

randyrat
01-04-2010, 08:25 AM
In the Speer load data book these loads are for Speer bullets ONLY. You'll find this throughout the speer manual and you'll find some of the hotest loads here. The data can be used ONLY if you work the loads up.
When they state the bullet they mean that specific bullet.

Work your loads up because each gun is different. You've heard it before.

afrance
01-04-2010, 09:35 AM
I thought possibly it was numbers being transposed during final editing of the manual. I just checked an older 2002 version of Accurate's load data and that has the same as the current PDF online.

Does anyone have Speer's #13 or #14 and can check if they are still quoting the higher powder charge or now closer to the Accurate numbers?

mpmarty
01-04-2010, 12:26 PM
Speer #13 page 545:
180gr tmj or gdhp
aa7 powder
8.7 start 895fps
9.7 max 972fps

mpmarty
01-04-2010, 12:27 PM
Same reference max velocity w/ 180gr bullet is with HS-7 9.3gr 1027fps

pt4u2nv
01-04-2010, 01:16 PM
In the Speer load data book these loads are for Speer bullets ONLY. You'll find this throughout the speer manual and you'll find some of the hotest loads here. The data can be used ONLY if you work the loads up.
When they state the bullet they mean that specific bullet.

Work your loads up because each gun is different. You've heard it before.

Agree,..But I have to apoligize in that the 180 I was loading was the GDHP not the XTP. I did work it up slowly at .1 gr at a time so that should not be an issue. Not sure yet where my high pressue is coming from especially since the later versions of the Speer state the same load !!!! I am definetly going to drop in down a bit under Speers min and se what happens. I will deal with the cast boolit issue once I get the j bullets under control. I have a friend with a 40 Smith that he is going to let me borrow to check throat dia and such to compare with mine to see if anything is way out of sinc.

afrance
01-04-2010, 04:25 PM
Thanks Marty for the confirmation of #13.

I just sent Speer this question through their Ask Speer online form. Once I get clarification I will post it here.

Alan

hydraulic
01-04-2010, 11:13 PM
PT: I shoot a .40 Sigma also. I use the old Lyman 40143 .38-40 mould, bullet sized .401, air cooled wheel weights, 5 grs. of Unique. This load shoots accurately, operates the action smartly, no signs of pressure, no problems. Brass is range pickups from Forest Service LEO's, mostly Winchester. Have no idea what the chrono says, don't care, doesn't matter.

pt4u2nv
01-05-2010, 06:38 PM
PT: I shoot a .40 Sigma also. I use the old Lyman 40143 .38-40 mould, bullet sized .401, air cooled wheel weights, 5 grs. of Unique. This load shoots accurately, operates the action smartly, no signs of pressure, no problems. Brass is range pickups from Forest Service LEO's, mostly Winchester. Have no idea what the chrono says, don't care, doesn't matter.

What weight is this bullet ? I am looking for loads for Cast using Unique and they seem really difficult to come by. Also what COL are you setting them at . Thanks

randyrat
01-05-2010, 07:00 PM
I'll have to look up loads in the forty for you. I used a ton of Unique, clays, Red dot, IMR4756 (great accuracy), #5..... I wrote everything down. I'll see what i can come up with in my notes. All pistols are different so they may or may not help you.
You have to use "comigulationizm" to come up with loads in the forty/cast and a chronograph helps also.

One load i do remember was 3.2 grs of Clays and a 200 gr bullet(not cast), the most accurate load i ever shot with the forty.

David2011
01-05-2010, 07:08 PM
.405 does sound awfully big and could be raising the pressure. I size to .400 (Star sizer and custom die) and can really tell a difference if I shoot commercial cast at .401. I went with .400 because .401 failed the Dillon case gage but it still shoots well enough for IPSC.

Pressure, recoil and velocity are all higher with .401 cast boolits (compared to .400 at the same powder charge) but even at 1045 fps the Winchester primers were only starting to flatten very slightly. At 940 fps or so they don't noticably change shape. I shoot a lot of .40 S&W and see cracked cases from time to time but I assume it's from fatigue. They don't usually split all the way to the mouth, though. Most split from above the web to 1/8" or so below the mouth- the area of max pressure and work hardening. Splitting after 2 or 3 loadings sounds pretty early, though. Most of my .40 attrition is due to loss in the grass at matches and competitors who don't care that the brass is clearly marked and not theirs.

Split cases are usually pretty easy to detect. They have a distinctive ring when dropped on a wooden table that comes through even when many are dropped at once. I can even pick up the different sound sometimes in a Dillon media separator.

hydraulic
01-05-2010, 11:48 PM
PT:

180 gr. bullet. I don't pay much attention to over all length. If it fits in magazine and feeds OK it's fine. I went down and measured one of the rounds and it's 1.1 in long. Of course, I don't shoot competition. I have a gong out at the ranch that I shoot at. Grandson's like to shoot. Sometimes we'll put up a target and try to shoot a better score than the rest of the family. Probably don't shoot more than 200 or 300 rds. a year. You may have loftier goals in mind than me, but this load shoots reliably and safely.

pt4u2nv
01-06-2010, 07:25 AM
After really looking close at everything I found out my calibers were off zero by about .005 so my info on the bullet dia being .405 was definitely not correct , I rechecked and it is .401. I just borrowed a friends data book and his .40 so I will try a couple of his loads in my gun and mine in his w/ chrony to see what is going on.

I did notice though in checking some of his loaded rounds that the base of his are around .415 and mine are anywhere from .425 to .430. A definite little bulge in mine. I took some unloaded ( by me) once fired brass and started loading some more with my cast vs commercial cast , same powder charge, variations of primers etc. to see if I can find anything out there. Just alittle too cold to shoot right now but hoping it will change a little by the weekend.

243winxb
01-06-2010, 11:56 AM
Check you powder scale while your at it.
After really looking close at everything I found out my calibers were off zero by about .005 so my info on the bullet dia being .405 was definitely not correct

JRR
01-06-2010, 06:40 PM
Buy a box of factory high performance ammo with the same weight bullet. Fire about 10-20 rounds and measure the pressure ring with a MICROMETER (not a dial caliper). Work up your load until your pressure rings are the same or slightly less than the factory.

Determine the maximum OAL that feeds and functions. This will reduce pressure a great deal and enhance accuracy.

Range brass that has been sitting out for awhile will be weakened from corrosion.

Good luck,
Jeff

pt4u2nv
01-07-2010, 01:57 PM
Check you powder scale while your at it.

Powder scale is fine .....I check that a couple of times during weighing. I cannot believe the calibers were off when I ran them back to zero though. I usually, especially when I am doing alot of checking, don't run the caliber back to zero in between cases.I assumed ( which is not good) that the set screw would have held it on zero. Just happened to think about the possibilites of what could be going on and saw it was not zeroed.

mpmarty
01-07-2010, 02:16 PM
Calipers are not a reliable source of measurment for our hobby. Get a good micrometer and you will be better served.

afrance
01-13-2010, 09:01 AM
Got this response from Speer:

"I suspect the difference is the tested bullet. Check with Accurate to see what bullet they used in their testing. Our tests would have been with the Speer GDHP. Current Speer data show that 8.7 grs-9.7grs of AA # 7 is a tested load with our 180 gr GDHP bullet."

Still seems that a Gold Dot would take up more case volume than a traditional hollowpoint of the same weight and raise pressures, not lower them. I will check with Accurate to see what they say.

Alan

lwknight
01-13-2010, 09:33 AM
It makes me to wonder, how much boolit is in the brass compared to the "J" bullets?
You really need to figure out your case capacity with each different load. If for example you are using 85% with one bullet and 95% with another, there could be radical differences.

One easy way I found to test capacity is to drop a bullet into a fired case with powder in it and see where the bullet falls to. Then add more powder till it stops at your desired seating depth. Weigh the charge and you have the 100% capacity. Divide your desired charge by the 100% charge and get the percent fill.

pt4u2nv
01-13-2010, 09:56 AM
OK I did of little more "testing" of some different powders, loads etc to try to figure out this issue. Loaded up some Dardas 155 gr Cast "store bought " boolits, 155gr J Bullets, from Hornandy, and 2 different alloys of my cast boolits. BHN of 15 on one and 9 on another just to eliminate the sizing or hardness issues. Rechecked the bore dia at .401 , bullets checked at .403 . All loaded at min loads with AA#5, AA#7 and Unique. Chrony was reading from 1100 to approx 1235 FPS on all of the loads lowest being the 170 gr cast of mine. I also shot these same loads thru a friends 40 ( S&W also) His gun registered the same FPS as mine so that eliminated the issue being the gun. I also shot a few of his J bullets he loaded and got 1232 FPS on a load he chrongraphed at 1150 avg. That being said he could have also got a reading of 1232 that just showed up as a high for him and not the avg. I now have borrowed his chrony to try this weekend to see if my new chrony is just not reading correctly. If his is consistant with mine I do not know where I will go next. Note: Plans are to check a box of factory ammo at this time also.

Comment on working up the load and look for pressure signs is great but I can't get off the min load at this point with any boolits cast or J without crazy chrony readings and high pressure signs. OAL has also been played with and still no changes in readings.


This is beginning to wear on me as I have tried everthing suggested by you all and all I know and nothing seems to change the high readings. I am also going to get another gun or so of mine that I had chrongraphed with an older chrony to compare notes against the new one but I am afraid I will find the chrony is fine.

243winxb
01-13-2010, 11:10 AM
Make sure the screens/timers maintain correct spacing. Long time since i had a chrony. Any one remember the card board with the wire used as a sky screen.

pt4u2nv
01-13-2010, 12:39 PM
Make sure the screens/timers maintain correct spacing. Long time since i had a chrony. Any one remember the card board with the wire used as a sky screen.

My unit is all one pc...no spacing to worry about.

9.3X62AL
01-13-2010, 01:17 PM
Something ain't right.

"Standard" velocities in 40 S&W/175-180 grain bullets with 4" barrels run about 950-975 FPS. I carry that bullet weight, and don't mess with any others. Most fixed-sight service-grade pistols in 40 S&W "assume" this load is being used (sighting, spring rates).

I've slugged A LOT of 40 S&W barrels, including several Sigmas. They are UNFAILINGLY .400" or .401", unlike the variance seen in 9mm throats and grooves. I'm glad that got cleared up.

I just mic'd the expander stem in my RCBS 40 S&W/10mm die set--.3965". The expander spud in the Lyman Multi-Charge expander die set is .3980". MUCH better for loading cast boolits of .400"-.401". I'm still not certain what your actual boolit diameters are, but you DO NOT need .403". Just the brass-working from the under-sized RCBS sizing die to the over-sized boolit will set up early brass failure, and likely deform your bullet as well. From .3965" to .403" is a HUGE jump. Most modern die sets--especially for autopistol calibers--"assume" jacketed bullet usage. Do a "tale of the tape" on your pistol's fired brass vs. its dimensions on sized brass--you'll likely get an eye-opener there, too.

Assuming your velocities are correct from the Chrony, you are overloading your ammunition. The early retirement of your brass and the "wiping" of headstamps is further evidence of same.

afrance
01-14-2010, 07:48 PM
I just received a response from Ramshot/Accurate's ballistician after showing them Speer's response that "8.7 - 9.7 grains of AA #7 was a tested load with our 180 gr GDHP bullet".

"Alan,

We can only confirm our own data.

We test in SAAMI certified test barrels and 8.5 grains is definitely the maximum for a 180gr JHP whatever the make.

Regards

Johan Loubser

Ballistician

Ramshot/Accurate Powders"


Definitely a prime example of needing more than one reliable source of loading data to cross reference and ask questions if those sources differ from one another. I wonder how often this particular load contributed to kabooms in 40 S&W.

Jayhem
01-18-2010, 02:56 PM
Wow. Lesson learned! Use only the load data published by the POWDER manufacturer, not a J-bullet manufacturer!

pt4u2nv
01-18-2010, 04:29 PM
I just received a response from Ramshot/Accurate's ballistician after showing them Speer's response that "8.7 - 9.7 grains of AA #7 was a tested load with our 180 gr GDHP bullet".

"Alan,

We can only confirm our own data.

We test in SAAMI certified test barrels and 8.5 grains is definitely the maximum for a 180gr JHP whatever the make.

Regards

Johan Loubser

Ballistician


Thanks for help in this matter Alan. I appreciate all the leg work. Now back to the original issue.....finally got some closure on the high pressure issues I thought I had with the cast and obviously "J" bullets , which was certainly justified No Thanks to Speer.

My "new " chrony was sending bad info, all FPS were approx 300 - 400 FPS faster than they were actually being sent down range. Double checked all my loads with a friends chrony right behind mine and all readings on mine were way high. His chrony was reading right at levels the bullets were supposed to be doing. Thanks all for the great help, learned alot about cast boolits thru this isssue and hopefully this will help others in the future. What a relief to finally find out it was not me , my boolits, or loading techniques.

Thorns though to Speer for sending me on a wild goose chase on overloading their bullets, compounding my problems when using their bullets to find out what was going on pressure wise when I thought it was my cast boolits.

sheepdog
02-19-2010, 02:15 PM
Thorns though to Speer for sending me on a wild goose chase on overloading their bullets, compounding my problems when using their bullets to find out what was going on pressure wise when I thought it was my cast boolits.

This is the same Speer that public denounced Lee factory crimp dies as "dangerous", warning people not to use them for fear of high pressures. But keep in mind Speer is owned by Blount the parent company of RCBS

jimkim
02-19-2010, 11:10 PM
I just received a response from Ramshot/Accurate's ballistician after showing them Speer's response that "8.7 - 9.7 grains of AA #7 was a tested load with our 180 gr GDHP bullet".

"Alan,

We can only confirm our own data.

We test in SAAMI certified test barrels and 8.5 grains is definitely the maximum for a 180gr JHP whatever the make.

Regards

Johan Loubser

Ballistician

Ramshot/Accurate Powders"


Definitely a prime example of needing more than one reliable source of loading data to cross reference and ask questions if those sources differ from one another. I wonder how often this particular load contributed to kabooms in 40 S&W.

This is strange. Hornady 7 shows 9.4gr AA#7 as a maximum load for their 180gr bullets, and Sierra V shows 9.2gr of AA#7. Could they all be wrong? I wonder if the newer AA#7 might be hotter.

dardascastbullets
04-30-2010, 08:36 PM
OK I did of little more "testing" of some different powders, loads etc to try to figure out this issue. Loaded up some Dardas 155 gr Cast "store bought " boolits, 155gr J Bullets, from Hornandy, and 2 different alloys of my cast boolits. BHN of 15 on one and 9 on another just to eliminate the sizing or hardness issues. Rechecked the bore dia at .401 , bullets checked at .403 . All loaded at min loads with AA#5, AA#7 and Unique. Chrony was reading from 1100 to approx 1235 FPS on all of the loads lowest being the 170 gr cast of mine. I also shot these same loads thru a friends 40 ( S&W also) His gun registered the same FPS as mine so that eliminated the issue being the gun. I also shot a few of his J bullets he loaded and got 1232 FPS on a load he chrongraphed at 1150 avg. That being said he could have also got a reading of 1232 that just showed up as a high for him and not the avg. I now have borrowed his chrony to try this weekend to see if my new chrony is just not reading correctly. If his is consistant with mine I do not know where I will go next. Note: Plans are to check a box of factory ammo at this time also.

Comment on working up the load and look for pressure signs is great but I can't get off the min load at this point with any boolits cast or J without crazy chrony readings and high pressure signs. OAL has also been played with and still no changes in readings.


This is beginning to wear on me as I have tried everthing suggested by you all and all I know and nothing seems to change the high readings. I am also going to get another gun or so of mine that I had chrongraphed with an older chrony to compare notes against the new one but I am afraid I will find the chrony is fine.

Sir,

I must interject - your mention that the bullets 'checked at 0.403"' I assume were the bullets that you casted? I ask this because I size all of my 10mm's to 0.401".

Matt