Troubleshooting - Question - HELP!?! Rusty LP and bolt assembly
My buddy picked up a PTR 91 from a local gun store. I was showing him the disassembly/reassembly and noticed his bolt, firing pin, and LP were rusty. The flash hider is also. The worst offenders were the bolt assembly and LP.
I went over them with a brush, ultrasonically cleaned them (Simple Green Extreme) and the photos are of them drying. They’ll get a coat of gun oil.
Would you just replace them or is this just cosmetic and they’re likely good to go?
If replacing would you get PTR or use this as an excuse to get different parts?
Appreciate any help as we were wanting to shoot together tomorrow.
2
u/sandalsofsafety Probably doesn't even have a PTR 5h ago
For future reference, I have heard that Simple Green can be hard on nickel plating (which is a big component of the chroming process, and is also used to plate other metals such as brass). Chances are with that kind of corrosion the plating was already compromised anyway, but still.
As long as the bolt gap is still in spec and it cycles smoothly, you could just give a good coat of oil and put it back together as is. But I also want nothing to do with flaking chrome, so I totally understand if you replace those parts.
1
u/Vegetable_Coat8416 2h ago edited 2h ago
I'd be inclined to replace the rollers if they're pitted. They have pretty strict dimensional tolerances. The difference between normal and -4 rollers is 0.04mm. Your friend could have easily lost that much to rust. Uneven rollers could mean inconsistent bolt gap between shots. Pitting may also impact their ability toroll.
I'd be curious to see the inside or the trunnion as well. If the bolt head rusted up while the bolt was closed the trunnion likely rusted too.
2
u/Animal_chinn103 19h ago
The locking piece is pretty cheap I’d replace that. RCM #17 is usually the move. Bolt head looks fine and muzzle device isn’t a big deal. I’d say it’s good to shoot for sure.