LMT MIM gas key failure

[dwd1985]

Are the keys on the Enhanced Bolt Carrier Groups also MIM? For what you pay they better not be! (I have 4 of them)

Pretty sure LMT developed the enhanced BCG after they stopped using MIM keys. I have 2 of the enhanced BCGs and neither of them has a MIM key.

[dwd1985]

You can see if your bushing is GTG, by shining a light down the chassis without the barrel installed. It's right above the barrel extension hole obviously.

Was able to take a look...removed both barrels from both uppers and shined a light in. I can see the triangle insert on both, nothing seems abnormal. Thanks for the tip though

[e z money]

Does anyone know which years of production LMT used MIM gas keys?

[rifleman8]

I have no useful info on when LMT did / did not use MIM anything.

In the past year I have purchased two new, non-enhanced, DI, 5.56 LMT BCGs from two different reputable suppliers. Neither key looks MIM. One key is phosphate / chrome-lined and the other key looks like Nitride - not chrome lined - on a phosphate / chrome-lined carrier.

Both BCGs look like straight-up ass.

In LMT's defense I have only made one attempt to contact them, which went un-answered. I have not pursued it further - really not interested in words coming from an organization that would ship such items.

[HKGuns]

Good on them for taking care of the issue.

Here’s to hoping the fixed the problem and not the symptom.

[sgtrock82]

Does anyone know which years of production LMT used MIM gas keys?

I do not have a concrete dates but I received a defective, malformed mim gas key on a BCG from LMT, which they quickly replaced with a new carrier with standard machined gas key. This was sometime around 2008-2009.

Sent from my BE2028 using Tapatalk

[bryan1211]

I have no useful info on when LMT did / did not use MIM anything.

In the past year I have purchased two new, non-enhanced, DI, 5.56 LMT BCGs from two different reputable suppliers. Neither key looks MIM. One key is phosphate / chrome-lined and the other key looks like Nitride - not chrome lined - on a phosphate / chrome-lined carrier.

Both BCGs look like straight-up ass.

In LMT's defense I have only made one attempt to contact them, which went un-answered. I have not pursued it further - really not interested in words coming from an organization that would ship such items.

FWIW, I emailed LMT yesterday afternoon and asked if their standard L7D3 BCG's have a chrome lined gas key. They got back to me first thing in the morning and said: "The bore and gas key are chrome lined."

I've been saving up to get one in my build, so it was worth verifying, before I finally ordered one.

[rifleman8]

FWIW, I emailed LMT yesterday afternoon and asked if their standard L7D3 BCG's have a chrome lined gas key. They got back to me first thing in the morning and said: "The bore and gas key are chrome lined."

I've been saving up to get one in my build, so it was worth verifying, before I finally ordered one.

I wish you the best with your build. Hopefully you have a better experience with LMT components than I did, Cheers.

[bryan1211]

I wish you the best with your build. Hope you have a better experience with LMT components than I, Cheers.

I do as well and thanks. So, far everything I've bought from them in the past 6 months has been great quality.

I've definitely seen people report some bad QC in the past couple of years. I'm just hoping it's a matter of new workers, sending stuff out that they shouldn't have.

[bryan1211]

Just an update for anyone that comes across this again. Received my LMT L7D3 BCG and it looks excellent. Smooth phosphate coating, great machining/ staking and the gas key is indeed chrome lined (and obviously not MIM).