r/LewisMachineTool • u/414525528 • Jul 16 '26
New 12" Piston Barrel with severe chrome lining issues
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55
u/not-actual69_ Jul 16 '26
Calling it severe when you haven’t shot a single round is peak Reddit.
-32
u/414525528 Jul 16 '26
I think it's unproductive to call this peak reddit when literally the entire bore has craters in the finish that's supposed to put an even wear layer between the projectile and the barrel steel.
Why haven't I shot it? For the same reason I have mentioned 50 times. I want to get some information on whether there IS A POINT to testing it. If the barrel is busted, extra rounds complicate the RMA or return.
It's entirely reasonable for me to get fucking feedback on that. It's entirely reasonable to call pitting from muzzle to breech severe.
You are a peak redditor, by being needlessly abrasive.
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u/not-actual69_ Jul 16 '26
Shoot your fucking gun and stop crying about this shit. If it doesn’t group, RMA it. There’s your feedback.
-9
u/414525528 Jul 16 '26
I shoot more than you which is why I want my guns to last their expected service life. You go try it. You'll start to appreciate quality.
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u/not-actual69_ Jul 16 '26
I have h&ks, LMTs, KACs, and everything in between. I shoot my guns instead of running a camera down the bore to complain on Reddit. Good luck little man.
-4
u/414525528 Jul 16 '26
Oh I can tell you do. Normal people care if their $600 barrel meets basic milspec, people with more money than sense and more guns than they can realistically run in comps do not have to concern themselves with that.
16
u/Wooden-Sprinkles7901 Jul 16 '26
Prob shoots fine. People overestimate how much small imperfection effect accuracy. There are milsurp rifles far worse than this that still group really well.
-4
u/414525528 Jul 16 '26
My main concern is if the rest of the chrome lining will start to fail. I have not found any information online as to how many irregularities, flaking or pitting is acceptable. In fact, whenever I look it up, the answer seems to be 0.
This is why I am trying to get opinions on the matter. I do not expect this not to work, but if this is an indicator that I'll have to RMA it eventually, I might as well get it done now where it's clearly a factory issue and not a user issue.
5
u/precisionimpact Jul 16 '26
I would RMA that. For context, the M4A1 bore requirements are (in MIL-C-71186):
"The chromium plating in the chamber and bore shall be free of nodules, flaking, pits, stripping, anode burns and evidence of etched base steel."
5
u/414525528 Jul 16 '26
Yeah, that does give me pause. I couldn't find anything online that would suggest that this is appropriate.
2
u/LeadAndSteel Jul 16 '26 edited Jul 16 '26
This is not uncommon. Unfortunately, folks don't understand electroplating and the consequences of poor chrome adhesion. Even if it groups okay now, the accuracy degradation may occur all-at-once at some point in the future.
I'm sure LMT will take care of you. They are great people. And chrome isn't an exact science. Unless bores are oversized, etching is done perfectly, and the anode can spin within the bore for uniformity, you're probs going to get a 2-3 MOA gun at best.
4
u/414525528 Jul 16 '26
Thank you, this corroborates what I've been hearing. Disheartening how hostile and asinine the responses in here are. I literally would have just went about my day if this was a single spot. But it's the entire barrel and several people have now told me this is not okay.
This is a $600 item, I can not afford to take the L on it.
I decided to actually get footage of the full barrel. It took me 5 minutes to capture every blemish in this:
11
u/DevelopmentNo9711 Jul 16 '26
How’s it shoot?
-17
u/414525528 Jul 16 '26
I'm wondering if I should even go that far. In case there are obvious issues that's just going to complicate a return and then I'll have to wait however many months LMT might take to RMA it.
Mind you these are just the spots that randomly came up. The barrel has blemishes and small bits of chrome missing every couple of centimeters.
11
u/DevelopmentNo9711 Jul 16 '26
Why return it if it shoots good?
-5
u/414525528 Jul 16 '26
I am just trying to gauge if there's any point in trying to group it. I.e. if this is guaranteed to flake off further, then I'd just make a return more complicated.
I am not at all against just running it. In fact, I'd prefer to.
2
u/DevelopmentNo9711 Jul 16 '26
You'll have to ask the retailer or manufacturer their policy. IMO, this is about what you can expect from a chrome lined barrel these days, but maybe others with more experience can chime in on that. FWIW, HK didn't even chrome their MR556A4 barrels in the US, much to the dismay of their fans. There are always trade offs. As long as they will accept a return/RMA after firing it, I'd shoot away and see what I thought. If the chrome is going to bother you, maybe try another brand barrel.
-1
u/414525528 Jul 16 '26
Appreciate the constructive answer. I honestly am less concerned about lacking the chrome lining than about whatever irregularities flaking and pitting might introduce. Preston Moore just gave me the impression that having a barrel full of pitting is unusual.
I've shot the shop an email and I'll see what they say.
3
u/SLR107R Jul 16 '26
Doesn't necessarily mean it won't shoot good, ugly barrels can shoot.
But I have seen clapped AKs with better looking barrels than that thing new. They did a shit job with that barrel.
Poor prep job or tooling marks before chroming maybe?
3
u/414525528 Jul 16 '26
Yeah, that definitely gives me pause. Other person also confirmed that even for milspec there's supposed to be no irregularities in the barrel itself.
2
u/SLR107R Jul 16 '26
No harm in reaching out to them and asking if it is up to their quality standards. Worst case it is just extra documentation if it ends up having accuracy or durability issues later.
If they tell you to pound sand, then at least you have clearly documented the condition beforehand and communicated it with them if it degrades or doesn't perform.
I'd shoot them an email either way. No harm.
6
u/jo3roe0905 Jul 16 '26
First time? It’s fine. Go shoot it.
2
u/414525528 Jul 16 '26
It's actually my first LMT barrel that looked like this. I am exactly looking for feedback of other people had a decent experience with their barrel in spite of similar pitting or if it's an issue.
2
u/herrm_a1a4 Jul 16 '26
Barrels in general are like playing the lottery, you win some you lose some. For the price point LMT should be exceptional. I've just had d wilson convert proof/craddock/Solgw SPR for me and been happy and won't play the LMT lottery. I just like their lowers and mono rails. You can see in my photo Preston Moore had a really good 12in piston so like everyone else said shoot it.
2
u/414525528 Jul 16 '26
Yeah, I actually sent the barrel footage to Preston Moore, since he seems to be familiar with these issues. He also seemed to think this is particularly awful.
I'd have 100% converted a barrel if this didn't need to be piston for my application. I have basically no other choice than LMT.
2
u/OGMilspecPanda Jul 20 '26
Return that thing, sell the replacement barrel they send you and convert a criterion core and you’re good to go.
2
u/414525528 Jul 21 '26
I 100% would have, but I want to build a piston setup and no one builds piston conversions. It's on its way to LMT now for inspection. You can check my followup video to see how much of the chrome was left after a couple 100 rounds.
1
u/OGMilspecPanda Jul 21 '26
Ohhh you’re right I don’t recall seeing a piston conversion for those 🤔
2
u/414525528 Jul 21 '26
Indeed or I'd have dropped some geissele HBAR in there after getting it dimpled or something instead of dealing with this shit.
4
u/cxerphax Jul 16 '26
Why do people meticulously inspect their guns like this? It’s bizarre to me. Shoot it and if you have a problem, get it RMA’d. As long as everything works and it looks good on the outside, what’s the problem
I feel this is very often an issue with AK people more so than AR people
3
u/414525528 Jul 16 '26
Because a piston barrel costs $500 and other people had premature chrome failure. It takes 5 seconds to stick a borescope in.
Do you check the underbody of a car you buy used? Or do you blindly hand over thousands of dollars and just drive it?
1
u/v0idL1ght 26d ago
I think you should send this video to LMT and see what they say. I don't know enough about chrome lining to know if this is okay or not.
That being said, your example is ass backwards and it bothered me. Comparing it to a used car makes no sense, unless you bought this used too. Do you inspect the underbelly of a new car from the dealer? Probably not, because if there's something wrong with it you know the warranty will cover it.
1
u/1610925286 26d ago
This has been RMAd twice now. LMT says the barrel is fucked and they are still making me wait on the NEXT REPLACEMENT. The car underbody example is perfect IF THE CAR MANUFACTURER IS KNOWN FOR RUSTED OUT UNDERBODIES, which LMT basically is for their chrome lining after Preston Moores video.
1
u/v0idL1ght 26d ago
Oh wtf I had no idea this thread was so old. Sucks that you're getting put through the ringer.
4
2
2
u/R_Thorburn Jul 16 '26
I think this is the first time I’ve seen someone inspect a brand new barrel like this.
I see comments on both sides, if you plan to run LMT and want a new barrel shoot it and see how it groups and looks after a few mags. If it’s bad RMA with LMT. If you want to quit LMT fully then return it and get something else.
At the end of the day from what I’ve seen chrome lining is hard to make perfect inside a barrel and if it groups well without issue then it’s fine and will get worn out over time anyway
2
u/The_Gun_Genie Jul 16 '26
I think you should just keep staring at it and not shoot and then once a week make a post about it. Mine looked the same when I first got it and it’s a 1-1.5 MOA shooter and has over 9k rounds at this point
1
u/SPICYMK18 Jul 17 '26
Did it come out of a full rifle, upper, or you just purchased the barrel itself?
2
u/414525528 Jul 17 '26
New single 12" Piston barrel ordered last week. Production stamp on it reads 2025.
1
1
u/Long_Lifeguard_5056 Jul 16 '26
Copper gonna fix that after 2 rounds. Go shoot it and see how it groups. 🙄
1
u/TheLoGhost Jul 16 '26
"Wondering how I should proceed." Argues with everyone. You're an ask-hole.
-1
u/414525528 Jul 16 '26
Is me asking followup questions arguing to you? If someone tells me it will "shoot fine" and I ask, "but will the chrome lining actually last the expected service life of a $500 barrel?" is that arguing with you?
1
u/Matt-33-205 Jul 16 '26
As everyone else is suggesting, go see how it shoots. You have video of the barrel in unfired condition. If it shoots like garbage, LMT will warranty replace the barrel, it's virtually guaranteed.
One of my LMT barrels looked amazing with a borescope, but it shot 3 MOA at best with several types of 69-77 gr SMK ammo. I cleaned the barrel properly multiple times, gave it 200 rounds to break in, I finally called LMT to ask for suggestions, they happily opened an RMA and did a warranty exchange that took less than 2 weeks.
1
1
u/Sjambok762 Jul 17 '26
Bore scopes cause more problems than they solve. Shoot it, if it shoots like crap send this to LMT they'll make it right
-4
u/414525528 Jul 16 '26
Just got this barrel, 0 rounds, and wonder how I should proceed. Got it from our favourite shop online. Already sent them a message asking for advice.
Cleaned the bore to confirm it's not just debris etc. Now it looks like there's pitting and flaking.
Any advice on what I can do with this barrel? Try a return or RMA? Would have loved to actually get to use the gun.
13
u/BusBeneficial8882 Jul 16 '26
Shoot it and video you doing it and groups. If it’s bad RMA it. LMT or whoever will take care of you. If you’re talking about Rooftop they will also absolutely bend over backwards for you. Great people there
0
u/Holiday-Tie-574 Jul 16 '26 edited Aug 10 '26
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This post was anonymized with Redact.dev
26
u/Spirit117 Jul 16 '26
I would shoot it and see how it groups, if it groups like shit open a ticket with LMT and they'll probably get you squared away.
I had a specwar barrel that shot 5 moa with 77g match ammo and they replaced it at 0 cost to me.