Split a couple of cases today. [Archive] - Glock Talk

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OregonG20
11-20-2011, 13:22
Went shooting this morning. Fired of 50 rounds of my new load, which is:

New Starline Brass
CCI 300 primer
14.0 gr's of Accurate Arms #9
180 gr Hornady XTP
COL = 1.26 inches
Stock Glock barrel

All 50 rounds fired just fine, nice and accurate and I never noticed a hiccup. After I collected all my brass, I found these two guys:

http://i243.photobucket.com/albums/ff260/roryhunt/DSC02415.jpg

Splits are in the middle, and don't go all the way to the top. I worked up to this load, and everything seemed fine. No flat primers, no excessive bulges.

As you can see in this photo, the split is happening on the side of the case as it is chambered, not top or bottom. I don't have any experience reading primer strikes on Glocks, but I think it is occurring on the right side of the case, if you were looking down the gun just as if you were aiming.

http://i243.photobucket.com/albums/ff260/roryhunt/DSC02413.jpg

I don't see these as flattened primers. I know flattened primers aren't the best way to judge over pressure, but I am not seeing any crazy bulges either. Everything seems fine, other than these two splits. Are these rounds over pressure? Is it weak brass? While using my Lee factory crimp die, am I crimping too hard or not enough?

Any thoughts or answers will be appreciated.

Taterhead
11-20-2011, 13:46
While that is a pretty warm charge for an XTP (Accurate has a max of 13.5), I would lean toward that being a defect of the brass. Splits like that are typically a brass problem rather than a pressure problem. Swampfox had an used withsome Top Brass a while back that were splitting like that.

I agree that the primers look good, but I also agree that primers condition is not the best indicator of good-to-go pressures.

cigarman454
11-20-2011, 13:57
Have to agree with Taterhead brass issue. I had one split today also it was a Federal cartridge 2nd fired case working up a load for some of my cast bullets well below book max.

nickE10mm
11-20-2011, 14:29
Those primer strikes look a bit cratered.... however, I saw this once before as being a brass issue. Still, tread with caution. That is quite the warm load, especially for a stock barrel. I would change the brass out and do another work-up with different brass to see.

_The_Shadow
11-20-2011, 17:40
I see it a s a combination of brass and a potent load! Brass shows expansion very low at the web area, therefore the chamber added to the affect as well.

This is exactly why we say that everthing is relevent and no two guns, barrels are alike when it comes to performance!

Federal brass is know for splitting like that due to its brittleness. I don't accept this as being the brass by itself!

99blkta
11-20-2011, 20:34
Just out of curiosity, what is the expansion on the case. I'm aware this probably has nothing to do with the cracks, and all barrels are different; however, that area in picture 2 has an weird reflection to it, to me at least.

oceanbob
11-20-2011, 20:51
I see the bulge..I see molten firing pin slots...I see split cases....I think you should back off .5 grain and call it good..:shocked:

Take care, Bob

rcd567
11-20-2011, 21:22
I see the bulge..I see molten firing pin slots...I see split cases....I think you should back off .5 grain and call it good..:shocked:

Take care, Bob

I've never met the man, although I hope to be in his will someday (he's building an airplane), I've read most of what he's written here and would heed his advice.:thumbsup:

MinervaDoe
11-20-2011, 22:00
I see the bulge..I see molten firing pin slots...I see split cases....I think you should back off .5 grain and call it good..:shocked:

Take care, Bob
:agree:

The Complete Reloading manual for the 10mm and .40S&W has a copy of the Accurate arms load data. It's interesting to note that they have data for Speer 180 grain JHP and Hornady 180 XTP. It's the same weight bullet, but the Speer 180 grain JHP has a maximum of 14.5 grains :wow: with a PSI of 32,600
While, the Hornady 180 grain XTP has a maximum of 13.5 grains with a PSI of 34,100.
i.e. Accurate Arms recommended load for the 180 grain XTP is one full grain lower while its PSI reading is 1,500 PSI higher.
Less powder, more PSI for the XTP.

21Carrier
11-21-2011, 06:08
Cracks like that are usually caused by brass that was not properly annealed at the factory. When brass is too hard it does not expand like it should, and just cracks. I had an old Federal case crack like that yesterday. It's no big deal when you're talking about old brass, but with NEW brass, it's somewhat bothersome. You need to measure your case expansion, and verify that it's still in spec. That load is pretty hot. However, I bet they would have cracked with a lighter load, as well. I would chalk it up to bad brass. The primers and strikes look typical of what I get from my Glocks.

leadslinger13
11-21-2011, 06:16
i have a tendency to agree with oceanbob

Jitterbug
11-21-2011, 11:15
From the Accurate Arms 3.5 Edition.

180 gr. XTP
12.2 gr. AA9 Min
13.5 gr. AA9 Max
WLP
1.250"
5" Barrel
34,100 PSI

The Hornady 7th lists 14.9 grains as max.

If I were splitting brand new Starline cases, I'd back way off to start loads then proceed with caution. Check and double check again with dummies for setback issues.

Recently I saw a thread listing all the "errors" in a well know reloading manual, quite a few. So always use two/three sources of published data and work up.

I have some old AA9 I've been using in .44 Mag. Based on my velocity readings it's way hotter then the newer powder, despite Accurate Arms telling me otherwise and I've experienced the same results with other powders. Each and every lot has the potential to deviate.

Moral, get a general consensus of published start loads and carefully work up.

The brass might be bad, may not, then again it only takes one bad piece.

Taterhead
11-21-2011, 11:35
Every so often I will see splits like that with new brass - even at lower pressures.

While I do suggest that the OP back down the charge (I bet those 180s are probably moving at a pretty good clip), I tend to agree with 21Carrier that a brass defect is at play. Vertical splits are not as worrisome as lateral case head fractures.

gator378
11-21-2011, 22:54
Went shooting this morning. Fired of 50 rounds of my new load, which is:

New Starline Brass
CCI 300 primer
14.0 gr's of Accurate Arms #9
180 gr Hornady XTP
COL = 1.26 inches
Stock Glock barrel

All 50 rounds fired just fine, nice and accurate and I never noticed a hiccup. After I collected all my brass, I found these two guys:

http://i243.photobucket.com/albums/ff260/roryhunt/DSC02415.jpg

Splits are in the middle, and don't go all the way to the top. I worked up to this load, and everything seemed fine. No flat primers, no excessive bulges.

As you can see in this photo, the split is happening on the side of the case as it is chambered, not top or bottom. I don't have any experience reading primer strikes on Glocks, but I think it is occurring on the right side of the case, if you were looking down the gun just as if you were aiming.

http://i243.photobucket.com/albums/ff260/roryhunt/DSC02413.jpg

I don't see these as flattened primers. I know flattened primers aren't the best way to judge over pressure, but I am not seeing any crazy bulges either. Everything seems fine, other than these two splits. Are these rounds over pressure? Is it weak brass? While using my Lee factory crimp die, am I crimping too hard or not enough?

Any thoughts or answers will be appreciated.

Had a few over the years in 10mm, 44 Mag, 300 Weatherby,and some in 308. Usually brass that has been used several times. Usually load close to max. I never recall any splits in new brass, just reloaded many times brass.