Firearms going kaboom is a scary experience, and it can happen with any firearm. From M16’s to AK’s, to the new kid on the block the ACR. A member at ACRForum.com had his Bushmaster ACR go kaboom at the range recently, he was lucky to walk away unscatched.
Bad ammo is thought to be the culprit, it cracked a bolt carrier, blowing out the ACR’s magazine and bending the extracter. There didn’t seem to be any damage to the barrel or receiver of the ACR however.