Well i made my purchase earlier this week.  Bushmaster XM15 model.  16".  Is there a break in period?  I brougt some Remington UMC ammo and it failed to extract properly almost every other round.  Could it be the ammo or is there something seriously wrong with my extractor?  other than that, i got it zeroed in pretty well and having fun with it.

Not being a smart-a$$ but did you take it apart, clean it, and then lube it up per the instruction booklet?  It's been my limited experience that of three Bushies I've owned, they've seemed to have a gritty residue on them when new and the actions seemed dry and gritty.  A good cleaning usually did away with these issues.

Good luck,
Scott

 I have never had a single FTF from my 14.5" Izzy.  It has been perfect right out of the box, as have my two Colts.  I shoot mostly 5.56, but have shot about 200 rounds of Remington .223 without incident.  I would try CLP in the bolt area, and perhaps a good overall lubing inside.  It really should not jam nearly as much as yours has, but there is still hope that you can get it straightened out yourself.  If you can't, don't settle for a gun that is overly finickey with different ammo types.  Send it back for another.

Quoted: Not being a smart-a$$ but did you take it apart, clean it, and then lube it up per the instruction booklet?  It's been my limited experience that of three Bushies I've owned, they've seemed to have a gritty residue on them when new and the actions seemed dry and gritty.  A good cleaning usually did away with these issues. Good luck, Scott

If it's brand new, it very well might need a GOOD cleaning/lubing before going to the range.  

Strip the bolt down, lube it, then proceed to the range.  Everything should work perfectly.  If it doesn't send it back.  Bushmaster is good about making things right.  I had an over-torqued barrel on my first Bushmaster, but I was so impressed with Bushmaster's customer service, I bought three more from them!

Quoted: If it's brand new, it very well might need a GOOD cleaning/lubing before going to the range.   Strip the bolt down, lube it, then proceed to the range.  Everything should work perfectly.  If it doesn't send it back.  Bushmaster is good about making things right.  I had an over-torqued barrel on my first Bushmaster, but I was so impressed with Bushmaster's customer service, I bought three more from them!

Agree 100%.  Clean it and lube it (and make sure you're using good USGI magazines).  But there really shouldn't be a "break-in" period, and the rifles are test-fired at the factory.  

If you STILL have any problems, call Bushmaster customer service and they will make it right.

I just purchased my first ar15 a Bushmaster 16" I took it to the range with 300rds of 45gr UMC and yes I had the same problem.  I also took apart my gun and cleaned/lubed it.  Out of 300rds I got 2 full 30rd magazines to fire without any problems.  I also shot 100rds of Wolf  with no problems at all.   If you look around these forums no one seems to have any problems with the UMC ammo.   I guess it could be a bad batch of ammo or maybe our guns do need to be broken in alittle.  Try some different ammo and see if it still does it.

Some/many/most AR type firearms (and indeed many kinds of mechanical devices) need a bit of a "break in" period when new.  In the AR's IMHO I would recommend first, cleaning the rifle well (particularly the BCG), field strip and clean off the typical "storage" oil.  Lube a bit more than normal with a lighter weight oil (break free works well), particularly around the contact areas of the bolt, gas rings, extractor and ejector, and especially the cam pin.  Also make sure you have some lube on the sliding surfaces of the bolt carrier and mating area inside the upper receiver, as well as the bottom surface of the bolt carrier and matching area of the hammer face.  Next you just need to shoot it... most AR's should be broken in and running smoothly after 200, maybe 300 rounds.