Cracked/split brass?photos up

B

bowhunter_0311

Sergeant
Full Member
Minuteman
Dec 24, 2010
109
1
38
South Texas
#1
I was trying out some new loads the other day, 168amax, 175smk, both had 44gr RE15. The 168's were running 2580fps, 175's 2540fps. The firearm is r700, 1/10, 20in. On one of the 168gr cases about half a inch up from the base of the brass all the way around there is a non perfect circle that you can catch with your fingernail. This is the first time that this has happened was wanting to know if yall thought that it might have been the LC brass or if the load was too hot. My normal load is 43gr. The max load per nosler is 45gr. There were no other signs of over pressure that I saw. Having trouble figuring out how to post pictures otherwise there would be some.

[img:center]
utf-8BSU1HMDAwNDUtMjAxMTAxMTEtMDcwNi5qcGc.jpg
[/img] [img:center]
utf-8BSU1HMDAwNDMtMjAxMTAxMTEtMDcwNS5qcGc.jpg
[/img] [img:center]
utf-8BSU1HMDAwNDYtMjAxMTAxMTEtMDcwNy5qcGc.jpg
[/img]
 
#9
Re: Cracked/split brass?

how do you figure once it is resized what is the diff? i know that the MG chambers are quite loose and that it is working the brass when resized. enough to start cracking cases? i have shot a good bit of it and work good.
 
#12
Re: Cracked/split brass?


Here's a pic of case head separation. The guy that shot this out of his M1A got a cut on his face from it not sure what actually caused the cut but he wasn't to happy. This was the 4th or 5th reload on that brass. Can't imagine it would happen on the third. Get a cut off wheel & cut the brass in half & inspect it might b where the die ended creating a shiney spot on your brass only one way to know for sure visually inspect.

IMAG0023-1.jpg
 
#17
Re: Cracked/split brass?

You are not addressing the root issue by dropping your load.

Section some of your 1x cases before you do anything to them. You can also drag a paperclip formed in the shape of a hook down at the head of the case and feel for a groove. Insert the paper clip from the neck.

Also section some of the cases from your 1x fired brass that did not separate.

One of these is on my bench at all times BTW.

Some 50 BMG cases are so bad that they'll tear right off on the first reloading after being shot in M2s with its user adjustable headspace turned way out.

case.jpg
 
#18
Re: Cracked/split brass?

IMHO 44grs of RL15 is deffinately to high. Don't forget your suppose to reduce the loads for L/C (military) brass for reasons Shootforfun just posted.

Sierra says 41.3 RL-15 with their 175

Hornady says 44.3 RL-15 with a 168 AMax

Your most likely to high with both loads as the reloading data Sierra and Hornady publishes is with commercial brass not Military brass.

A Hornady head space guage might help you here. I know when I resize L/C brass the first time it's blown way out from loose auto chambers. After you resize the brass and shoot it out of your remington 700. Measure that fired brass with the Hornady Head space guage, when you resize it the second time set up your resizing die to bump the shoulder back .002 any more and your over working your brass. Let's say for example when you resize the brass now you bump the shoulder back .010 after a few reloadings it will cause the brass to be stretched out where that case head seperation happened (in the picture)the brass gets hard over time from resizing and firing in the neck shoulder area and it quits flowing once it gets hard the case head is where all the stretching gets done because the neck, shoulder area no longer flows. It pulls the brass apart from the pressure.

That's the whole idea behind anealing, it keeps the brass soft on the neck shoulder area so it flows and repeat resizing and firing doesn't work the brass so hard in the case head area.

Don't forget it just might be where the die stopped on the brass when resizing. It creates a shiny spot in the same general area where the case head separation occurs it's Kind of deceiving.

Also A USMC Vet Semper Fi
 
#19
Re: Cracked/split brass?

Thanks for the info.
1st I wouldnt mind buying some lapua brass but I have thousands of 7.62 rds I see no need to buy any if I can make them work and be safe effective/accurate rounds.

2nd I agree that the load may be a little high and I worked up to where it was at. IMHO sierra is very conserative nothing wrong with that. In the end safety is the biggest concern and sierra is way.......on the safe side.

3rd I will be cutting into some of the rounds here soon and checking others with the paperclip great piece of advice.

4th And this is the reason I am a member here on the hide. I am not familiar with head space and how to measure it. And I also am having a hard time on understanding how you only bump the shoulder back .002 When I resize brass from my chamber I use a neck sizer only, can bumping it back .002 be done with this die?

Semper Fidelis
 
#20
Re: Cracked/split brass?

Neck sizing it only sizes the neck and as far as I know doesn't even touch the shoulder area. I full length resize since I shoot AR's, an M1A, and Garands along with A couple Remington 700's and 1903A3's. The auto's need the extra room for reliable feeding.

We need another Duty expert on neck sizing only. Sorry Brother, That shoulder bumping is for the full length sizing process. I can never tell with a paper clip cutting a piece of brass is easiest for me 1 piece won't break me. And like you said safey is paramount. Yeah Sierra might be on the slow side but most often the best accuracy isn't at the top of the cartridges velocity range. probably around 100fps less than max velocity.

Thinking about that once fired brass if you only neck sized it I wonder how it's fitting in your chamber. I measured the once fired L/C I bought from a vendor it measured 3.184-3.194. it's about .020 longer than my Winchester once fired brass it measures 3.178 and after I resize it it's 3.176.

Lapua Brass it would be nice, maybe one day if I build a 6mm BR...

Post some pics when ya get a chance its fairly easy using Photobucket. Just create an account download your photo's to Photobucket then copy the image address next to your picture and right click when you get to the Hide and paste
 
#21
Re: Cracked/split brass?

Ok I didnt give up all the info, I full length resize for the first reload all reloads after that are done with the neck sizer.
If I didnt full length resize them the first time there is no way that they would fit into the chamber.


 
#22
Re: Cracked/split brass?

Forster makes an excellent die for bumping the shoulder and neck sizing. I know Sinclair sells them. It uses bushings for neck tension adjustment and wll allow you to set the right amount of bump.
I hate to bring this into the post, but Remington has been not so hot with the reamer lately IMHO. I have seen several that were just plain S#@*ty.
The other thing I would consider is annealing the brass before I went any farther. Being once fired in something full auto and then being sized back to min spec when processed seems to be quite a workout for the brass.
Also, you might want to fire some FGMM or Hornady TAP factory ammo and inspect that brass as a "control" load.
 
#24
Re: Cracked/split brass?

_9H has been giving you some excellent advice.

Either your chamber is out-of-spec (not near as likely), or your resizing die is OVER-BUMPING the shoulder (very likely).
This is the single most common error in reloading bottle-necked rifle ammunition.

The used machine-gun brass isn't helping things either and I would remove it from the equation for now.

Over-bumping can even give you flattened primers without having the pressures normally required to do so.

I'd buy a .308 case gauge and invest some time in setting my resizing die.
You'll know what I'm talking about the first time you drop one of your loaded rounds into the gauge.
The pisser is that in order to set the die properly, you will need a small supply of brass that really needs to be resized.
(your newly purchased gauge will let you know, and will teach you a lot about what is going on in there.)
Buy some new 308 cases (50 winchester for ex.), check the new cases in your die (they should be fine) and load then up and shoot them.

Set your die using these cases, and things will become clear what has been happening.

Oh, and you may not want to re-size any more of that fired brass or you'll end up with a case head stuck in your re-sizing die.
Toss it, it's trash now.
 
#25
Re: Cracked/split brass?

If the cases in question headstamps aren't either marked "match", M-118 LR or FIREd by the user as surplus then you need not delve any further into this issue until you buy some different brass.

Because as Jerkface alludes to 99.5% of the time a case not marked as above was<span style="font-weight: bold"> fired in a machine gun. Pretty much rendering it worthless for reloading purposes.
</span>

Annealing will do absolutely NOTHING to "fix" a case with excessive thinning above the web from previous firings in a generous chamber or excessive shoulder pushback. The case head thinning occurs when the firing pin pushes the case all the way to the front of the chamber BEFORE primer ignition where afterward high pressure stretches the casehead back against the bolt face. Annealing the neck shoulder will have absolutely NO effect on this.
 
#26
Re: Cracked/split brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">_9H has been giving you some excellent advice.

I'd buy a .308 case gauge and invest some time in setting my resizing die.
.</div></div>


What kind of case guage do you recomend to pick up?
 
#27
Re: Cracked/split brass?

There shouldn't be anything wrong with using ex-military brass, but you have to remember that it has a smaller case volume than .308 brass. Most say you should reduce powder loads by a couple grains from the published .308 loads to get a proper load for military 7.62, so 43.5 grains in .308 brass becomes 41.5 grains in Lake City brass.

I'd back the load off a couple grains, compare damage done to the brass between the two loads, and go from there.
 
#28
Re: Cracked/split brass?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Hamilton</div><div class="ubbcode-body">

Over-bumping can even give you flattened primers without having the pressures normally required to do so.

</div></div>

Been there, done that, and the sectioned case below was done when trying to diagnose the problem. Flat and side flowed primers, mild load, separating heads.

OP, as much as it pains me to admit it, I came to these conclusions the hard way. Plus, I have advice from Jerry Hazlett, who has an ammo mfging company called Amer-I-Can. He buys from .gov. Buying brass for more than scrap value is a risk because a high percentage of the brass can be unusable when it shows up. 50 can be really bad.

Good luck getting it diagnosed.
 
#29
Re: Cracked/split brass?

RCBS Case Mic or like I said b4 Hornady headspace guage. With Hornady's setup you get all the case inserts for most every cal. With rcbs you have to buy one for each bullet and they're pricey. They both measure the fired brass so you can bump .002 off your chambers fired brass.
 
#30
Re: Cracked/split brass?photos up

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">There shouldn't be anything wrong with using ex-military brass </div></div>

Except that the chamber dimensions in the machineguns trash the brass.
 
#31
Re: Cracked/split brass?photos up

Oh Man, it looks like its about to come apart yikes!!!! I wonder how much those nasty old auto chambers have stretched out your brass. Can you post a sectioned piece that hasn't been fired in your rifle? That's Bogus if you've been sold once fired brass that can't be reloaded at least 3-4 times. Agreed that annealing a severely damaged piece of brass will do it no good.

Here's an official explanation of annealing and it's benefits

http://www.6mmbr.com/annealing.html
 
#32
Re: Cracked/split brass?photos up

Here is an example of a case gauge:

http://www.sinclairintl.com/.aspx/sid=67675/pid=33287/Product/WILSON_CASE_GAUGE_308_WINCHESTER

In the picture, do you see the groove milled in the top of the gauge?

That is the allowable headspace range.
Use a straight edge, like a razor blade, to check cases, and set your re-sizing die accordingly.
Take your time, and remember that brass has springback, so a long shoulder might not always get pushed back into spec.
When your dies are set properly, everything that goes in spec or greater, comes out spec.
 
#34
Re: Cracked/split brass?photos up

I cut into a handfull of cases today some were once fired ffrom my 700, others havent been reloaded yet. And in one of the not reloaded cases I found this...

[img:center]
utf-8BSU1HMDAwNDgtMjAxMTAxMTItMTgwNi5qcGc.jpg
[/img]

might just end up scraping the shit, or bumping the charge WAY down.
 
#35
Re: Cracked/split brass?photos up

Make you a feeler pick like _9H shows earlier in the thread. You can check/sort the cases. If they have a thinned groove on the inside (you will feel it), set those aside as scrap.

On the ones that don't have a groove that you can feel with the pick, get a headspace gauge of some sort and properly set up your dies to bump shoulders .002" from your chamber headspace. Without headspace gauge, back off the sizing die, size the case and try in your chamber. Keep incremently (1/20 to 1/10 of a turn) screwing in the die, sizing and checking in your chamber until the bolt will just close on the sized case. Lock it in and you are good to go.

I think the most important thing is to sort the cases fired in a "loose" chamber from the good cases. If you can't feel a groove near the case head, then they will last you for several reloads with properly adjusted dies.

BLK7
 
#36
Re: Cracked/split brass?photos up

I ran into the same problem witth 7.62X51 LC brass fired from an M60. Some of the brass was so oversized I couldn't fully resize the brass. A few spilt after 1 reload. After that sold over 1000 of them for scrap. Not worth the trouble or the danger and/or cost of a catastrophic failure.
 
#37
Re: Cracked/split brass?photos up

Scharch.com will make a discount/exchange for your old brass and then you can buy some better brass...if you get it from them, Just a thought and you wouldn't totally loose out. About 24.50 off a thousand 223. so it should be more for .308. Good luck.
 
You must log in or register to reply here.

Similar threads

Devo10ate
Where am I going wrong? .308 hunting load and general powder questions
Replies
12
Views
700
Snuby642
Snuby642
Kamerad
SOLD *added more 2/19* WTS 308 ammo; 30 cal ELD-X 200 gr projectiles
Replies
7
Views
747
Kamerad
Kamerad
T
M14 with Lothar-Walther heavy profile 6.5 Creedmoor barrel testing (ongoing)
Replies
4
Views
462
Red_Foreman
R
N
LC brass and loading for shorter 308 gas guns
Replies
3
Views
441
Mike_Honcho
M
S
SOLD 300wm, Stiller, Bartlein, McMillan - Roberts Precision built
Replies
9
Views
2K
Chernobyl
C
Top Bottom
Back
Home
Forums
Merch
Alerts