A friend of mine is going to give me his AR to look at.  He says that when he goes to chamber a round the bolt slides forward, catches a round but gets caught up and fails to feed.  The strange part is that he says the bullet itself gets forced inside of it's own brass case.  I know he has only tried WWB so far.  I told him I would look at the gun for him but I've never heard of this problem.  Does this sound familiar to anyone?

+1 on starting with the mags, or maybe he's possibly 'riding' the charging handle instead of releasing it and letting the buffer spring close the bolt.

I did think of mag problems, he probably only tried one.  This guy is an experienced shooter but admittedly knows very little about diagnosing/ fixing problems.  I'm going to start with a thorough cleaning, visual inspection, basic function test, check his mags, and try different ammo. I will soon have the gun for inspection but am trying to do some recon before starting my project.

Good luck!

Quoted: A friend of mine is going to give me his AR to look at.  He says that when he goes to chamber a round the bolt slides forward, catches a round but gets caught up and fails to feed.  The strange part is that he says the bullet itself gets forced inside of it's own brass case.  I know he has only tried WWB so far.  I told him I would look at the gun for him but I've never heard of this problem.  Does this sound familiar to anyone?

FYI - This condition you have described above (highlited in red) is known as "SET-BACK" and it can occur at anytime with any type of 223/5.56 bullet. On rifles with but normally without M4 feed-ramps.

As noted above mostly likely cause of the problem here is the magazine.

Mike

ETA - please NOTE: set-back is a dangerous thing, in that should that bullet get "set-back" without the shooters knowledge and either thru the use of the foward assist or other means be chambered and then fired......., someone is more than likely gonna find themselves pickin AR15 pieces outta their teeth.

NOT a good thing and one should NEVER intentionally drop the hammer on a round that has had the bullet set-back, as this can very easily create an "over-pressure" issue.