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Posted: 10/19/2025 8:33:02 AM EDT
[Last Edit: MK19][Edited]
So I picked up a couple of the LMT piston-specific bolts from d.wilson last summer and tossed one into my LMT 14.5 piston rig. I have about 3k rounds through it and I last ran it about 3 weeks ago. I didn't break it down and wipe the BCG down like I normally do. Well, FFWD to yesterday when I was headed out to run a range exercise, I couldn't get the BCG to operate, it was stuck closed. I mortared the rifle and broke it down to find the following:    The cam pin is FCD and it also appears to have suffered some damage as well. The room I keep the rifle in is relatively well climate controlled, so I can't figure out how the rust got so bad. I generally oil down the BCG lightly, but admit I hadn't in a while. I am pretty shocked TBH. Has anyone seen anything like this before? |
f that noise...
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Originally Posted By MK19: So I picked up a couple of the LMT piston-specific bolts from d.wilson last summer and tossed one into my LMT 14.5 piston rig. I have about 3k rounds through it and I last ran it about 3 weeks ago. I didn't break it down and wipe the BCG down like I normally do. Well, FFWD to yesterday when I was headed out to run a range exercise, I couldn't get the BCG to operate, it was stuck closed. I mortared the rifle and broke it down to find the following: https://i.imgur.com/yTPlJtC.jpeg https://i.imgur.com/Nld51h2.jpeg https://i.imgur.com/ZG2MZi5.jpeg https://i.imgur.com/rIJJavb.jpeg The cam pin is FCD and it also appears to have suffered some damage as well. The room I keep the rifle in is relatively well climate controlled, so I can't figure out how the rust got so bad. I generally oil down the BCG lightly, but admit I hadn't in a while. I am pretty shocked TBH. Has anyone seen anything like this before? In addition to what ammo was shot, what do you use for lube? |
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Originally Posted By RD20: @MK19 Any updates? Ah, sorry about that. YES! In doing some thinking, I realized that I probably helped cause this myself due to some swiss cheese modeling. Well, I shoot suppressed exclusively, which as we all know keeps more carbon in the chamber area. Well, add that to the moisture already present (gun room humidity is roughly 40-50% at any given time) and the carbon and gun powder residue act like sawdust, retaining the moisture and allowing for corrosion and rust to grow. Anyway, that's what I came up with. So, I cleaned everything and now none of my rigs are stored with a round in the chamber and I haven't had any issues since. |
f that noise...
|
Originally Posted By MK19: Ah, sorry about that. YES! In doing some thinking, I realized that I probably helped cause this myself due to some swiss cheese modeling. Well, I shoot suppressed exclusively, which as we all know keeps more carbon in the chamber area. Well, add that to the moisture already present (gun room humidity is roughly 40-50% at any given time) and the carbon and gun powder residue act like sawdust, retaining the moisture and allowing for corrosion and rust to grow. Anyway, that's what I came up with. So, I cleaned everything and now none of my rigs are stored with a round in the chamber and I haven't had any issues since. I have a few LMT rifles I shoot suppressed I usually clean a few days after trips I have NEVER seen this with LMT I did see this with some corrosive Norinco ammo about ten years ago Completely my fault, knew the ammo was corrosive, forgot to clean immediately Suspect the ammo you used is to blame, certainly not LMT |
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