I bought two such rifles recently: Predator in 6.5 CM and Ranch in 5.56 NATO. Both have this thing that screws on the end of the barrel. Both were loose on both rifles when I got them new. The guy at Academy sold me the Predator. I asked him about the loose muzzle cap. He said use a crescent wrench. I though he was full of solid horse waste. I talked to Ruger customer service. The woman there on the telephone said the MUZZLE CAP or BARREL CAP screws on hand tight. I was told by Ruger not to use oil on the treads of these caps. I guess I'm not supposed to put shotgun choke tube lube on them also. The Ruger Predator has to go back to Ruger for some gunsmith work under warranty. The matte black finish is wearing off the receiver, small spots, from nomad gun cleaning with rubbing alcohol, armorer's toothbrush, clean white patched and some 30-year-old RemOil I still have in a spray can. I use gun oil ever so sparingly. The gun is also hard to get into battery chambering a round from the magazine. The bolt has to be shut hard in order to rotate into battery position. If the bolt is not rotated into battery and opened again, a round in the chamber might fail to extract as this is the el-cheepo push-feed type. Oh, by the way, speaking of new rifles, this notion of "breaking in rifles" by the way is pure solid horse waste. My Ruger manuals say nothing of the sort.