Just put together an M-4 stlye AR.  I'm running a 14.5 barrel.  Shot it for the first time and put 100 rounds through it without problem.   When I went to clean it,  I noticed that the buffer is getting beaten-up around the edges by the retaining pin .  Do I need a heavier buffer like an H?  If so, where can I get one?  Thanks.

What brand lower?

A heavier buffer will not fix the problem. It is commonly due to the buffer retaining hole being slightly too far back from where it should be.

The buffer is supposed to contact the carrier, which holds it back from the retaining pin.  If the hole is too far back, the buffer is striking the retaining pin rather than the carrier.

An easy fix is to cut a piece of material (doesn't matter much what it is made of as long as it doesn't break/shatter/crack and it can be securely glued to the face of the buffer).

I've used a small piece of lead sheeting, commonly available as roof flashing. This is about 1/16" thick, which is fine unless the hole is really buggered. Cut a small circle about 1/2-5/8" in diameter. This will be smaller than the face of the buffer. You want to build up the center  area where the carrier contacts the buffer, not the edges. You have to make sure that the edges where the retaining pin contacts the buffer are not covered by this piece, otherwise you'll just end up with the same problem.

Securely attach the piece to the center of the buffer. A good contact cement or super glue should work nicely. You don't want it to come off and jam up your firecontrol parts. Put the buffer back in the lower and turn it to make sure that the retaining pin doesn't touch this material. When you close the upper, you should see the carrier contact the buffer and push it slightly back into the tube and hold it back so that it doesn't strike the retaining pin. Pull the charging handle and release it to let the bolt fly foward. Open it up again to make sure there are no new indents around the edge of the buffer. If there are, cut another piece and glue it over the 1st piece and try again.  Any more than this and you've got a hole that is so far off that if it is a commercial product, return it. If its something you made yourself, you can keep adding layers until the problem disappears (within reason). It won't bother or hurt anything.

Besides lead, you can use a piece of aluminum, or even a small piece of rubber. I like the lead as it adds a little more weight to the buffer than other materials. Don't use plastic, glass, ceramic or anything that will break or crack. Cardboard (not corrogated) can be used, but it tends to get eaten up and shreads requiring frequent replacement, not to mention the paper fibers fouling up your fire control parts.

Does it look llike this?  


Mine was caused buy the sharp edges on the rear of the carrier. At first I thought it was from the buffer retainer. You should feel the sharp edges on the back of the carrier with your finger. I used a dremel with a polishing bit to get rid of the sharp edges and it fixed the problem.  I fixed the buffer marks by a sheet of sandpaper on a flat table. Sanded the marks till it was gone.  Looks new again.

Hope this helps,
556man

I don't think so. I'm sure he would have mentioned if it had a Big Red X!  

Quoted: I don't think so. I'm sure he would have mentioned if it had a Big Red X!

Yep.  Hunt101 is down.  It was working this morning.

Sorry,
556man

If its just getting scratched up that is normal.  If its getting chewed up the receiver is out of spec.  I had an early Essential Arms cast receiver that was like this and was replaced under warranty.  That was in 1987.

neilfj,
I think that's exactly the problem.  I'll try your solution.   Wouldn't reducing the edges of the buffer also work?

Yes, that would work too, as along as you don't remove big hunks of the buffer and reduce its weight significantly. Reduce the edge as high and slightly deeper than the dent made in the buffer, all the way around the buffer.

Quoted: Quoted: I don't think so. I'm sure he would have mentioned if it had a Big Red X!   Yep.  Hunt101 is down.  It was working this morning. Sorry, 556man

Use Imageshack.us to host your pics... they are awesome.

You might look at one of these.
www.brownells.com/aspx/NS/Store/ProductDetail.aspx?p=19699&title=AR-15%2fM16%2fAR-10+AR+BUFFER+PAD

Most time it is just the raised edge on the carrier notch scratching the buffer face like the picture showed and that can be fixed pretty easy.

lotsa good advice.  As has been mentioned the rear of the BC should bear on the face of the buffer when everything is correctly dimensioned.   It should leave a "fuzzy ring" on the buffer where the circular end of the BC is bearing on it.  If you have the upper "shotgunned" open and are closing it, you should see the rear of the bolt carrier bump into, and push slightly back, on the buffer.

Rather then installing an aftermarket widget to fix things, maybe consider just removing the buffer retaining pin.   It's only purpose is to hold the buffer assy in place when you open up the upper and lower receivers.   You just have to remember to catch the buffer assy. (because it will spring out) when you shotgun the upper receiver from the lower.

just my humble .02.

Quoted: Quoted: Quoted: I don't think so. I'm sure he would have mentioned if it had a Big Red X!   Yep.  Hunt101 is down.  It was working this morning. Sorry, 556man Use Imageshack.us to host your pics... they are awesome.

Thanks glockguy40.  I'll try Imageshack next time.  Is it also free like hunt101?  The problem is the only picture I got of the marks on the buffer is at hunt101.

Thanks,
556man