its suggested around here not to use UMC.  Ive used more than 1k roudns of wolf and brown bear(mostly brown bear) withought issue.  I bought 3 boxes of UMC and had my first malfunction 2 days ago.  Because of the reputation i checked all the rounds(twisted the bullet with my fingers) and all seemed firm, but when shooting, i had a FTF.  pulled the actionp back and saw an "empty" sitting on top of the mag.  after pulling it out, i saw that the bullet had pushed nealy all the way into the casing.  The bullet is sticking out 3/16ths of an inch.  the edge of the casing caught the feed ramps and stuck.  When playing with it it fed.  Had it fed whilst shooting i could have had a blown up gun.  Needless to say i will not be using umc anymore(unless i get a bolt gun).  Just thought id share another tally...  I highly recomend not using this stuff in your ar, better off with steel.

edit - oops, sorry for wrong forum, mods

I won't use UMC .223 for two reasons:

1) it's overpriced

2) too many QC issues (especially bullet setback you mentioned)

Same here, it costs more than top quality mil-spec ammo, and for an AR with a 5.56 NATO chamber which can use military ammo, the Rem.UMC stuff is inferior in every way. they don't even use boat-tailed bullets, but flat-base ones. hell, even the cheap Russian ammo has BT bullets, WTF is wrong with Remington?

Sounds like a typical issue with UMC.