Hey Guys, I have an early model MVP Predator in 5.56mm. I have never had an issue with it, Id say the closest thing to having a problem was finding ammo that the gun fired accurately. AE red box, 55gr. 223 and Winchester Varmint-X rounds are most accurate and I can fire them all day and the rifle is a tack driver. I live in the NE US and have only tested it out to 200 yards. Being that mine is an early model, the barrel is 20"question, unthreaded "sporter" style. My question is, has anyone ever tested the 20" sporter to compare against the 18.5" med bull barrel? What are the differences? Ive noticed that the medium bull barrel is a 1/8" thicker diameter at the muzzle. Is that little bit really enough to make a difference?