Chewed up brass

[thunderbolt]

I've been processing my old brass and found quite a few cases with chunks taken out of the head. I took out some unfired Federal XM193 (Lake City head stamp) and verified that it was my rifle doing it. So please look at the picture below.



What's causing this? (Ejector or extractor)

How do I fix it?

And is this brass still good to reload?

Thanks for the help.

[FLIGHT762]

The brass looks like it's hitting something as it's being ejected out of the gun. Do you have a scope or dot sight mount near the ejection port? It does not look like an extractor or ejector mark left by an AR-15 type rifle. You didn't state what type of rifle your shooting. Look at your receiver near the rear end of the ejection port area. Look to see if there's some brass smudges on something there. You should be able to see it.

[thunderbolt]

Sorry about that. Most of these were shot out of my AR. I'll look at my mounts for impact scars. I did notice that the case deflection part of my upper just forward of the forward assist gets dinged a lot and has lots of brass colored marks but they wipe off easily and havent mared the upper so I didn't think that was it. But I couldn't figure out what on my bolt was causing this so maybe I'm looking in the wrong place. Thanks.

[gunboat]

"good to reload" yes --remove burr with a smooth file if it interferes with shellholder --

[Brd_Hntr]

Do you have a dummy round? If so, chamber a dummy round and carefully eject it to see if the marks are present from chambering a round.

[Sky_DiveR]

You must have an AR with a carbine gas system. Your AR is firing just a touch out of time. Upon firing, the brass expands to seal the in the expanding gas. If you will look directly opposite from the burr, you will see a bright spot on your brass. Both the burr and the bright spot match up exactly to the extractor gap and the ejector hole on your bolt face. That bright spot and the burr is where the brass flowed into the ejector hole and extractor gap on your bolt during firing. The bolt is literally unlocking (turning) when the brass hasn't fully shrunk back to size and is still clinging to the walls of the chamber resulting in the burr and the bright spot.

Installing a heavier buffer and/or heavier buffer spring, should retard the timing enough where that doesn't happen. If you don't reload or don't care about the burrs then don't change your buffer/spring. I'm sure your carbine fires just fine, otherwise.

[thunderbolt]

Wow. Thanks. I didn't notice the other spot until you pointed it out. I'll look into a heavier buffer/spring to fix this. Thanks again.

BTW can you run the longer rifle length buffer in a carbine tube?

[Sky_DiveR]

...BTW can you run the longer rifle length buffer in a carbine tube?

Nope.

Look for an H2 or H3 carbine recoil buffer.

http://www.midwayusa.com/viewProduct/default.aspx?productNumber=651570

You can also do the cheap way if you have #9 lead shot. Pop the plastic cap off, dump out the weights, fill with shot, and replace cap. Adjust weight more or less to fix the timing.

Might want to look at Tubbs SSS springs too.

http://www.midwayusa.com/viewproduct/?productnumber=693755

[SixPointEight]

You must have an AR with a carbine gas system. Your AR is firing just a touch out of time. Upon firing, the brass expands to seal the in the expanding gas. If you will look directly opposite from the burr, you will see a bright spot on your brass. Both the burr and the bright spot match up exactly to the extractor gap and the ejector hole on your bolt face. That bright spot and the burr is where the brass flowed into the ejector hole and extractor gap on your bolt during firing. The bolt is literally unlocking (turning) when the brass hasn't fully shrunk back to size and is still clinging to the walls of the chamber resulting in the burr and the bright spot.

Installing a heavier buffer and/or heavier buffer spring, should retard the timing enough where that doesn't happen. If you don't reload or don't care about the burrs then don't change your buffer/spring. I'm sure your carbine fires just fine, otherwise.

Innnnnnnnteresting. That explains why my AR is doing that.