LMT MIM gas key failure

[La26]

I'm thinking that they fired 60 rounds to function test it. If the tube on the gas key is not damaged now, but gets damaged again like it did the last time, then the previous post about a misaligned gas tube could be correct.

[dwd1985]

I'm thinking that they fired 60 rounds to function test it. If the tube on the gas key is not damaged now, but gets damaged again like it did the last time, then the previous post about a misaligned gas tube could be correct.

Could be. My tax stamp just came back, so I am actually going to swap the 16" barrel out for a 10.5" and sell off the 16", so I don't know if the process will repeat or not. Also going to swap the semi BCG for a full auto one since I plan to drop in a binary trigger.

[ALCOAR]

I wonder if your missing, or have a busted bushing in the MRP chassis that indexes the straight gas tube back into the upper receiver portion.

Seen damage just like you reported from that.

[dwd1985]

I wonder if your missing, or have a busted bushing in the MRP chassis that indexes the straight gas tube back into the upper receiver portion.

Seen damage just like you reported from that.

I would be extraordinarily pissed off if that is the case. Considering that LMT had the upper in their possession for two weeks, if they didn’t figure that out and fix it, that would be a major black mark for their QC.

[georgeib]

I would be extraordinarily pissed off if that is the case. Considering that LMT had the upper in their position for two weeks, if they didn’t figure that out and fix it, that would be a major black mark for their QC.

Just see if the gas tube moves when you push on it.

[ALCOAR]

I would be extraordinarily pissed off if that is the case. Considering that LMT had the upper in their possession for two weeks, if they didn’t figure that out and fix it, that would be a major black mark for their QC.

Yours would be the second case I've seen of a problematic gas tube index bushing in since 2009....and it looks like yours isn't a case anyway. Your MIM gas key is the first one I've ever seen damaged, and I use the term damaged specifically instead of failing. I'm not sure we have any evidence the MIM gas key actually failed when an otherwise non MIM gas key wouldn't have. Could be a structurally failure of the material, but it also could be damage caused by an unknown culprit at this time.

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.

[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.

What is it supposed to look like? When I shine the light down the hole with the barrel removed, it looks as I think it should...but with nothing to compare it to, I could be wrong.

[ALCOAR]

What is it supposed to look like? When I shine the light down the hole with the barrel removed, it looks as I think it should...but with nothing to compare it to, I could be wrong.

It's a triangle that has the tip pointing towards the top rail....

[ABNAK]

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

[dwd1985]

It's a triangle that has the tip pointing towards the top rail....

Thanks for that detailed pic! I will have to check this afternoon once I get home to see. I also have a newer MRP upper, so I will pull both barrels and do a side-by-side to see if anything looks different between them,