I have a Savage 99 takedown in 250-3000 that the owner complains will not group well as the barrel is loose in the frame. I've never messed with one of these before and upon unscrewing the barrel I noticed two things. One, the threads were bone dry and two, there is a fair amount of slop in the threads that is not noticed when the barrel is fully screwed in. Putting it back together I see that the barrel will turn past the proper position that would let the key in the forend iron lock it in place. To fix that, I thought about small center punch marks on the barrel shoulder to raise just enough metal so that the barrel stops turning in the correct location and that may be sufficient to tighten it all up so that it shoots well. I also wonder about peening the the tops of the square or acme threads to tighten up that engagement. I will also apply grease and inform the owner that lubrication is important. The rifle is about 100 years old so I'm sure there is some wear in the threads. Do my plans sound reasonable? It seems I do not have many options with this.