So I am out at the range the other day and there is a guy with a new rifle there. He is having a really tough time of it. He just put together an AR15 and he can't get it to fire more than two shots in a row without it choking. He claims he fired it before this and it worked just fine (isn't that always the case) and that he has been putting together ARs for awhile.

At first I am thinking it is a magazine issue because the bolt keeps riding over the top round in the magazine without picking up a new round (or even budging it from position). So I throw him one of my mags that I know performs well - no luck at all. Still getting the same malfunction and the mag that doesn't work in his gun, works fine in mine.

So now I'm thinking maybe an out of spec magwell that keeps the mags from being at the proper height? However, we still get the occasional round to feed and have managed to fire about 10-15rds when we get a new malfunction - failure to extract with a stuck case. The case is sticking in the chamber and we have to slam the gun on the deck while yanking on the charging handle to clear it.  This ejects the spent case and examining it we see no pressure signs though the extractor has nearly torn the rim off pulling the case out.

At this point, I am thinking the rifle is seriously and permanently hosed and is probably a bad combination of budget parts and inexperienced assembly when the guy says he is going back to his car to get the regular buffer. I express skepticism that the wide range of problems we have been seeing can be explained by the type of buffer used; but figure that it can't hurt to try.

So we replace the super-heavy buffer that was put in there to reduce recoil and the rifle runs with no problems at all 100% and starts eating from the same mags it wouldn't feed from earlier as well.

Just thought I would mention this here; because if you told me that the type of the buffer could cause bolt-over-magazine failures and failures to extract due to stuck cases, I'd have said you didn't know what the hell you were talking about. In any case, it was an interesting day.

Could be tight tolerences from an gun that hasnt been broke in.  HB just adds to too much resistance.  Once the gun is broke in, I'll bet the Hbuffer will funtion fine.

Tex78

""So we replace the super-heavy buffer that was put in there to reduce recoil..."

what caliber is this thing ??