Quick question about brass

[09cs]

At the range today, a guy next to me was shooting an AR10, and let me have all of his 308 brass. It seems that all the brass I've looked at so far seem to have a small dent on the body of the brass, underneath the neck that looks to be in the same place on the ones i've looked at all ready. Is this something to be worried about or am I safe to go ahead and load these?

Thank you!

 

[leadbullet]

Don't worry about it, it will fire form back to the chamber of your rifle, simply full length resize and you know what to do next.
Cheers.

 

[givey]

I would size a few first and see how they chamber. Even after I size some of my AR-10 brass they are very snug in my R700 .308. I have not tried a small base die to see if it makes a difference, just sort brass to each rifle. The AR's seem are hard on the brass.

 

[918v]

SB dies do make a difference.

 

[High Binder]

The dent is from the ejected case hitting the little defector on the body of the AR as it exits. It's no big deal and will be gone when you fire form the brass in your chamber but you will need to FL that brass before you use it or at the very least check its head-space.

 

[09cs]

My thoughts were it was from the deflector as well. Thanks for calming this newbies fear!

 

[SpeedyR]

+1 on the deflector. I picked up a bunch of factory headstamped 300AACBO a while ago and notice that a lot was like that. turned out fine once fired, but hadn't noticed that much on 556 or 6.8 brass so I was a bit concerned but it's all good.

 

[JoshcBoucher]

My brother had an older HK that mangled brass. 1/4 in. dent. I didn't buy it for that reason. The military "1 fired LC", I just got have small dents that will fire form out, but it really screws with case capacity/accurate loads.

 

[High Binder]

My brother had an older HK that mangled brass. 1/4 in. dent. I didn't buy it for that reason. The military "1 fired LC", I just got have small dents that will fire form out, but it really screws with case capacity/accurate loads.

No, it really doesn't. Your most accurate loads aren't found until you fire-form (make consistent) the brass to your chamber anyway so a little dent that might displace 1/50ml in internal capacity isn't going to make a discernible pressure difference for it's first firing and won't even exist after it's fire-formed.

 

[samnev]

No, it really doesn't. Your most accurate loads aren't found until you fire-form (make consistent) the brass to your chamber anyway so a little dent that might displace 1/50ml in internal capacity isn't going to make a discernible pressure difference for it's first firing and won't even exist after it's fire-formed.

I agree, the small amount of indentation after resizing and fire forming won't change the internal volume much. You can always verify this if it bothers you.

 

[bigedp51]

60,000 psi will iron out any dents in the case and many AR reloaders pad the deflector to keep it from denting the cases. A 7.62x51 military type chamber will be .002 larger in diameter than a standard .308 chamber and also longer in headspace. With a standard die if you pause for three seconds at the top of the ram stroke you will minimize brass springback. Doing this lets the brass know who is the boss and to stay put after sizing. If this doesn't work then a small base die may be needed to bring the brass back to minimum dimensions.

No, it really doesn't. Your most accurate loads aren't found until you fire-form (make consistent) the brass to your chamber anyway so a little dent that might displace 1/50ml in internal capacity isn't going to make a discernible pressure difference for it's first firing and won't even exist after it's fire-formed.

When you full length resize a cartridge case it will conform to the internal dimensions of your die and not the chamber. The Late Jim Hull of the Sierra test lab and competitive shooter had the follow humorous saying about full length resizing and accuracy.

"I get my best accuracy when the case fits the chamber like a rat turd in a violin case"

A full length resized case with minimum shoulder bump is supported by the bolt face and the bullet in the throat of the chamber. The body of the case and the neck are not touching the chamber and as long as the case is concentric it has no influence on case alignment with minimal case neck runout .

 

[JoshcBoucher]

Well then, I feel better. Thanks for that. Been reading a "bunch" of the reloading advice and trying to reload "better". Guess I'll just make some "pretty damn good ammo", and not perfect ammo. I read some comments about weighing cases, separating by "volume", etc. It's starting to drive me a little nuts (OCD). I don't really want to get into neck turning, either.

No, it really doesn't. Your most accurate loads aren't found until you fire-form (make consistent) the brass to your chamber anyway so a little dent that might displace 1/50ml in internal capacity isn't going to make a discernible pressure difference for it's first firing and won't even exist after it's fire-formed.