AR-308 brass life

A

arlaunch

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How many firings are you guys/gals getting out of your AR-308 brass?

What type of brass etc.

After the new Krieger barrel break in, I took 12 pieces of brass out to make 4, 3 shot groups. My plan was to keep loading those 12 cases until failure.

I ran the 168's between 2550-2650fps for 2 firings, Then the 175's between 2500 - 2575 for 2 more firings.

Brass will no longer hold a primer real firmly. Maybe it would have been fine....

I tossed all twelve into the garbage last night.

4 firings seems to be the limit at those pressures. I mostly used IMR 4064.

I am still investigating if the brass gave out early due to chamber pressure or early extraction due to port pressure.

I am using regular Starline .308 brass
 
ADG brass is made using the double-struck head for extra hardness in that area. Not cheap, but worth a try. Lake City brass is famous for hard heads, too.

What brass were you using?
 
I'm cheap, so my standard may be too low.

As long as the primer doesn't move in the brass pocket by its own weight, even with non-crazy tapping on wooden bench, the brass is good enough for me. Believe me some brass I have used would have primer dropping out of the pocket by its own weight with only one firing.

With all my other lousy, stingy standards, I get to shoot more than 20 firings on regular basis.

-TL

P.S. I have heard of swaging tool that rolls the brass head to tighten primer pocket. Maybe that would help. After a few iterations the metal will be work hardened.

Sent from my SM-N960U using Tapatalk
 
I am using regular Starline .308 brass
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Take that same brass and using the same loads fire them from a different rifle, such as a bolt action. Then see what your case life is.

If there is any difference you now know that it's not the load, it's the load and the AR combination.
 
Usually only using brass for 3 (4 most) full power loads from semi, with the Ar being the easiest on them.

If your primer pockets are expanding, might want to give details of your load. Have never used Starline 308 brass, but 308 brass seems to vary widely in case capacity. Case head swipe has been associated with port pressure in 308 ar's?
 
Brother's very accurate Kreiger barreled Armalite AR-10 T goes about 4 loads before loose pockets.
I know his favored powder is Varget. Bullets,168.maybe 175. He backed down at least one gr from book max. Maybe more.He does not load book max.

He buys virgin WW brass. He sizes to carefully controlled head clearance.

I'd say with common brass, about 4 is typical. Lapua brass has a rep for holding up to many loadings, I've heard of 14 or so. I have never bought or used any Lapua brass
 
Several years back I was shooting Rem 150gr CLs as my only hunting loads from a short 16.5" barreled little Ruger. It just worked and worked well.

I had picked up a bunch of the bulk bullets and a good supply of LC cases. When I decided to work up a load I used H4895 and worked to duplicate the velocity of the factory ammo. Once I finally got my first AR I went straight to these loads and they have shot great. So far I have 6 plus loads on some of those original hundred cases. The load is very mild and plenty accurate for hogs or deer out past 200yds.

I did try out some 168 and 175's just to see what the rifle would do and like you found that pressures jumped rather quickly. I just decided that the original loads work plenty good and can be used in all rifles with no worries.
 
Sierra's bullet accuracy tester told me if you don't get at least 25 reloads per case, you're doing something wrong.

I've got over 40 reloads on Winchester 308 cases in bolt action rifles.
 
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I'd mic unfired brass and then compare it to fired brass to see how much stretch you're getting. AR 10 cycling is pretty rough on brass and bashes it around pretty hard. You might possibly have a pressure issue if your case heads are "letting go" that fast, I would suspect you would also see distinct "ring around the head" on the case if your pockets were letting go that fast.
 
Unclenick said:
In an M14 or other self-loader? He's running an AR-10.
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Never reloaded cases from semiautomatic rifles because their bolt faces were never squared up.

For best accuracy with semiautomatic rifles, some have found a bolt that won't close on a GO headspace gauge then had its face squared up to barely close on a chamber GO gauge.
 
Depends on where you are measuring. Growth on firing will only be by as much as the headspace is longer than the head-to-shoulder measurement of the case (head clearance). Much of the growth in overall case length appears when you resize because it extrudes that extra shoulder up into the neck.
 
Gas guns can be hard on brass. Extraction and ejection happen with considerable force. Some, if not all, FAL pattern rifles have an adjustable gas port, which can be tuned if you are throwing brass into the next county. Yes, you will see marks on the brass, and the rims can get banged up with repeated loading and firing.
Personally, I use military surplus LC brass for ammo I plan to run through it. Not about extreme accuracy, but I save my Starline and other new brass for the bolt guns only.
 
Growth on firing will only be by as much as the headspace is longer than the head-to-shoulder measurement of the case
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This is what I use.
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