I am new to AR's so bear with me. I recently got a new Bushmaster M4 carbine...and have put about 200-300 rounds thru it. So far it has functioned flawlessly...except when I used some garbage ammo. My question is this...I have noticed that the gun feels "loose". When I grip the VFG, I can feel some play between the upper and lower receiver...when the bolt is forward. When I lock the bolt back...it tightens up. This is not a big deal...I just want to know if this is a normal occurance in an AR15, or is there something wrong with my rifle. Thanks for your help.

Perfectly normal movement. What kind of junk ammo you useing to cause malfunctions?

I was using Ultramax reloads...had I known what I know now about that ammo...never again. Luckily I had no explosions...but I had some bizaare malfunctions with that stuff.

bump

Yeah, that's normal.  If you want to tighten up the wiggle, get an "accuwedge."  It does nothing for accuracy, but it will take out the wiggle room between the receivers.  It's a small piece of rubber, and fits in the rear of the lower receiver.  

Normal.

Thanks for all the replies...I'm glad to here it is normal. I will look into that Accuwedge thing...