i wanted you guys to take a look at my firing pin and tell me if this was a known problem w/ piston ar15s? Mine is the LMT piston if you didn’t know and I’ve fired roughly around 800rnds? Here are some pictures of my firing pin, it looks really gashed, everything else on my bcg looks normal (from what I can tell) I’m still new to this rifle platform.
Should I just switch my LMT to DI once I get money? What will I need in order to do that for the mrp system? can I just buy a normal DI barrel and install that and will it work with the BCG I already have in my gun? Or do I have to buy a new BCG along w/ that barrel? Thanks for your help
Wear in that area is normal. If the wear is beyond surface wear, and there is actually material missing, or a burr forming, then there may be an issue. If so, I would suspect your BCG cycle speed is too high, meaning the BCG is getting hammered more than it needs to be. Is there a way too adjust your gas piston system ( like: suppressed - unsuppressed)? Are you running a suppressor?
no suppressor, everything is stock LMT. I don’t know of any adjustment thing. There’s the piston rod and top piece, but there doesn’t seem to be anything to adjust.
What receiver extension, spring, and buffer are you using?
Maybe you have a soft cam pin?
It is hard to tell exactly, to what extent the cam pin is worn/damaged, to determine if it is normal wear or not. If there is actually excessive gouging, I would contact LMT, if it were me.
I was reading fast, and missed the MRP part before making my first post, so I guess you wouldn’t have any adjustment options. I never saw where you mentioned it was a complete factory rifle, as opposed to a piston upper, placed on your lower.
So, are the marks I see finish wear, or actual divots in the metal?
I just installed an LMT enhanced bolt carrier in my 6920 along with a new cam pin, bolt, and firing pin. I shot about 300 rounds through it and my cam pin has the same wear marks as yours.
I compared to my original cam pin and the wear is definitely more profound on the new parts. I compared the cam pin tunnels on the two bolt carriers and I think the cause is due to a combination of LMT’s tunnel configuration and the freshly machined edges. I think that as I put more rounds through it the machined edges will smooth out and then I will throw in a new cam pin.
so you’re saying just keep wearing the gun out more? like I haven’t had any malfunctions out of any of my shots all of them that i’ve shot, but the wear worried me, they look pretty deep, but i dunno. you can barely tell by moving your thumb over them, but def some difference in surface. I contacted LMT and they told me it was normal wear and all the piston rifles did that, which didn’t really make sense. does this mean that I’m going to have to replace parts on it all the time just because it’s a piston rifle? I bought the rifle on impulse not knowing much about the ar15 platform, mostly just shooting 10/22s and my glock 19, but the local gun dealer that I went to which is Clyde armory (https://policeguns.com/catalog/) he sold me into the piston mentioning how it had the same function as the ak47, so basically the same reliability, plus my BCG would be a lot cleaner and cooler & all of this sounded wonderful to me being a noob, not realizing it seems like a gimmick and is only eating away at my rifle, which I spent a little more on because I wanted a solid AR rifle that would last and had a reputation.
I don’t have one of those on mine, where did you get that bolt spring and can I use that on an LMT? I read somewhere on their site that they only use LMT barrels and stuff because of the way their MRP is set up which is kind of a bummer because it limits the customization options and I can only use LMT barrels/bolts and stuff, but I guess on the other side everything they make should be quality.
As you are clearly not familiar with the parts or function of your carbine, I suggest a recalibration before asking about a “known problem”… inferring issues with LMT’s products.
Cam pin is a bearing surface, when metal on metal force is transmitted, it will show surface wear.
Surfaces wear spots are where one should grease/lube
Is there a functional problem?
Piston MRP’s should have a H2 buffer and a reputable recoil spring. How is your lower configured?
If a DI MRP barrel is purchased, a regular bolt group is used.
While I can’t be of much help to the OP, I figured I’d play with fire a little bit and say this.
It seems like the OP is being scrutinized a bit much, for this site. If this sort of trial-by-fire for a new guy was on ARFCom, I could understand since it’s ARFCom afterall, but here? Come on, guys. I come to this site because the posters are by and large more mature and less likely to chew someone and spit them out. Maybe I’m just reading into some of the responses in a different light than they were meant to be, but they seemed to come across a little harsh to me.
if you expect spoon-fed, non-justified, ignorant, back-slappery… probably the wrong forum to
I expect discerning interaction in places I frequent… or I don’t.
The reality of the www is that there is frequent “viral” advertising & unfortunately detraction campaigns from less than ethical parties. If one purports a “problem” with an established and well recognized product… stand by clearly articulate & justify your words
Its normal my LMT’s cam pin looks like that. I will say It took about 1500 rounds through my DI with enhanced LMT BCG to get to that point. The cam pins need to replaced for good PM any ways.
To the OP I would use it but I would keep an eye on it if it keeps getting worse replace it. Other than that just replace it at normal intervals every 3-5k for good PM.
Spend money for new parts ever 3-5 rnds? I don’t think that sounds very good. I bought the LMT in the first place hoping I wouldn’t have to replace anything and that it would be a rifle to lasts, guess not. If I’m going to have to keep putting money into this thing for it to work then it’s not something I want. I’ll probably trade it in and get a nice WASR ak47 and a glock 19 and be done with it. I’m not a plinker anyway, I just want a rifle/handgun for survival/defense purposes.
K stand for thousand every 3000-5000 rounds. The buffer spring life is normally 3000 rounds give or take. If you want a rifle with the least PM requirements designed for any retard to run then the AK would be it.
Yes, I know it was every 3000-5000 rnds, I know what “k” stands for. I also know that you shouldn’t have to replace weapon parts every “xx-xx” rnds. A weapon should last a life time with what’s in it. You have AKs/1911s/garands, why should this gun be any different?
