damaged brass in AR

[Tradesalot]

Hey everyone,
brand new to the forum and brand new to reloading. My question to everyone: is it the nature of the AR platform (mainly LMT's) to dent and ding brass more so than bolt action rifles?
I just made my first hundred cartridges, fired about 30 of them, and every case has the same ding in the neck and I'm not sure if they're safe to reload. Its just a very slight dent, almost scratch like but i'm a little apprehensive about reloading them.

Im shooting a LMT .308, 16in chrome lined, 1/10.
.308 Lapua brass, 175 gr SMK HPBT, 42.7 gr hodgdon powder (H4895), winchester primers

Im also using PMAG's but loading one round at a time.

Does anyone have any insight as to what's causing the damage?
Thanks Everyone

 

[284driver]

Brass gets abused in an ar. This is normal. Load em up.

 

[Steve Blair]

They are dinged on ejection. You should find some brass marks on the upper receiver where they hit. As per the previous advice, load em up.

 

[Tradesalot]

They are dinged on ejection. You should find some brass marks on the upper receiver where they hit. As per the previous advice, load em up.

I did find some marks on the upper and actually put some rubber on it to prevent the brass from getting dented. what im seeing is actually on the case neck and its more of a scratched dent (for lack of a better term) very small but still present. More like a very tiny gouge mark. But thanks for the reply, ill take everyones advice and load em up. Im probably making a bigger deal out of it than it is. Thanks again guys.

 

[broncman]

Feedramps on AR style rifles can be leave almost like a gouge type scratch if fed from a magazine. Little work with a dremmel can take the sharp edge of the feedramps.

 

[Lapua40X]

... I'm probably making a bigger deal out of it than it is. Thanks again guys.

IMO, you can't ever make a too big a deal out of a reloading circumstance that raises questions in your mind. It's always better to be safe than sorry; and you can be VERY sorry for having overlooked issues related to reloading. Congrats for having the presence of mind to ask the question.

 

[37Lincoln1]

If you are shooting them one at a time, try hand feeding the round instead of putting it in the magazine. Then check and see if you get the same marks or not. At least that way you can eliminate whether its occurring from the mag to the feed ramps.

 

[bigedp51]

1. The spring tension on the extractor "controls" to a degree how the cases are ejected.

2. The gas port pressure also has effect on ejection.

3. Dent in the neck are related to above.

4. Scratches on the neck are the feed ramps and the ramps can be reshaped and polished.

Feed Ramps.
http://www.ar15.com/archive/topic.html?b=3&f=118&t=511200

 

[bglenn]

Another place to look is the locking lugs on the barrel extension. When the case clears the chamber the neck hits (slams) this area and leaves a scratch. A little less pressure from the ejector helps but you will still have some scratches. A gunsmith can take the barrel extension off and polish the area and help. But in my opinion other than looking bad, it won't affect anything. Just shoot it and go on. Hope this helps.

 

[infantrytrophy]

Do the marks on the necks look anything like those shown in the picture below? If so, this is caused by the feed ramps. There is no effect on accuracy or on brass life expectancy. Just shoot and don't worry about it.

There are some similar longitudinally-oriented scratches that are caused by the locking lugs in the barrel extension. Typically these marks do not extend all the way to the case mouth. Similar to the marks described above, these are insignificant. Just shoot and don't worry about it.

Dents in the case mouth are caused by the case striking the case deflector of the upper, just behind the ejection port. These dents straighten out when you size the brass. If you want, you can stick a piece of self-adhesive velcro (the "soft" side) on the case deflector, but it's not necessary.

Randy

Scratches on case neck and bullet caused by feed ramp. These are insignificant.

 

[Tradesalot]

Do the marks on the necks look anything like those shown in the picture below? If so, this is caused by the feed ramps. There is no effect on accuracy or on brass life expectancy. Just shoot and don't worry about it.

There are some similar longitudinally-oriented scratches that are caused by the locking lugs in the barrel extension. Typically these marks do not extend all the way to the case mouth. Similar to the marks described above, these are insignificant. Just shoot and don't worry about it.

Dents in the case mouth are caused by the case striking the case deflector of the upper, just behind the ejection port. These dents straighten out when you size the brass. If you want, you can stick a piece of self-adhesive velcro (the "soft" side) on the case deflector, but it's not necessary.

Randy

Thanks for the information gents, much appreciated.
Randy the picture you posted is similar to what I have happening. the scratches in my brass are a little deeper and do not extend to the case mouth so I'm inclined to believe that it is the locking lugs from what you said about it. Thanks for clearing things up. Also, i was getting some dents from the brass deflector and i just wrapped some rubber around it and it took care of that issue.

Scratches on case neck and bullet caused by feed ramp. These are insignificant.

 

[tome]

I dent every piece around the shoulder..this is a new Bushmaster , so i called Bushmaster . their customer service guy said it was from hitting the brass deflector.the rifle runs perfect and supprised me how accurate it was with just about everything i ran thru it. i'll full length re size and i'm go to go.

 

[Old Navy]

If you are just shooting rocks and pop cans in your local gravel pit those scratches won't hurt a thing. If you are loading 80 grain Bergers for 600 yards eliminate the cause. Later! Frank

 

[infantrytrophy]

If you are just shooting rocks and pop cans in your local gravel pit those scratches won't hurt a thing. If you are loading 80 grain Bergers for 600 yards eliminate the cause. Later! Frank

I respectfully disagree. The picture above is a 6HAGAR practice load, and this upper was good for a 198-9X at 600 yds shooting 105 gr Bergers. The two 9's were missed wind calls at 3:00 and 9:00. A .223 upper that produces similar scratches was good for several 200/high X cleans (including two 200/17X scores) on the MR31 target at 100 yards. These scratches tend to go away as you shoot more rounds through the upper, and they have no effect on accuracy.

You can try to "fix" the non-problem with a dremel tool. but there is no real reason to do so.

 

[mac86951]

I dent every piece around the shoulder..this is a new Bushmaster , so i called Bushmaster . their customer service guy said it was from hitting the brass deflector.the rifle runs perfect and supprised me how accurate it was with just about everything i ran thru it. i'll full length re size and i'm go to go.

Glue/Tape on a small piece of felt on the brass deflector. Dented cases gone! A Brass catcher will also help this issue.

-Mac