Gemtech suppressed bolt carrier, LMT MRP 10.5, SiCo Saker 762 on M16 lower - amazing

[Slippers]

Someone connected with Gemtech please persuade them to make a drop in BCG for our beloved LMT MWS weapon systems. They would sell one metric shit ton. Anybody running those guns with a can would sign up IMHO.

I gotta say, I want to grab one for my SBR's to play with. A member was kind enough to loan me one but I still never took the plunge. This thread may have cost me dearly.

PB

There's a thread on sh where someone used the gemtech 308 carrier with a JP high pressure bolt in their MWS. The JP bolt includes their own firing pin.

[Pappabear]

There's a thread on sh where someone used the gemtech 308 carrier with a JP high pressure bolt in their MWS. The JP bolt includes their own firing pin.

I read that thread but found it to be more confusing than that. I appreciate you simplifying that thread. I thought he bought 3 pieces of kit to make it run.

PB

[Slippers]

Too bad the 7.62 sbc is pretty scarce. Plus the combined cost of the carrier and jp bolt is $450+.

[Pappabear]

Too bad the 7.62 sbc is pretty scarce. Plus the combined cost of the carrier and jp bolt is $450+.

Yea, your approaching custom new barrel cost.

PB

[Slippers]

Yea, your approaching custom new barrel cost.

PB

Or spending a hair more and buying an ACC instead of an MWS depending on the deal.

[JoshNC]

I was pretty skeptical, too. And I'm not happy with some things about the carriers. The 308 version can't fit an LMT MWS firing pin, for instance. The staking on the gas key on every carrier I have seen is messy, leaving large burrs. The gas key screws are YFS. Basically I replace the gas key and screws with Colt or BCM parts, and stake it with one of Ned's tools.

As far as performance goes, it's not a bandaid for a super overgassed gun, especially with short barrels. The gun needs to be reasonably gassed to begin with, and then the carrier works wonderfully. JoshNC's 10.5 Noveske barrel is good example. It definitely helps a little, but the barrel is overgassed so the recoil is a bit harsher and the rate of fire is faster than my MRP. I have also used the Gemtech carrier on my BCM 11.5" and it runs well in that.

Gemtech has some cyclic rate data available that shows how the carrier is able to keep the rate of fire closer between suppressed and unsuppressed settings with longer barrels, while short barrels don't see the same results (i.e. the Gemtech carrier can't quite slow down the rate of fire as much when suppressed).

I was very skeptical until you purchased one and we shot it. It is a great addition to a suppressed AR. And to your point about it not being a bandaid for overgassed uppers, I think my two overgassed mk18 uppers demonstrate this rather well. Though they are confounded by their use of 5.56 cans vs. your 762 can.

Which reminds me, I still need to order some BRT ports for those two uppers. And a GT SBC.

[Singlestack Wonder]

My first use of the Gemtech bolt carrier was limited to testing the premise of whether or not it did an adequate job of diminishing gas to the face. As previously stated, it did that well over the course of firing 20 rounds. Yesterday I went to the range to run drills and shot 200 rounds over the course of 30 minutes. I run a Saker 5.56 on a BCM 11.5" SBR. I noticed that the handguard and upper receiver heated up exponentially more with the Gemtech bolt carrier vs. the standard BCM. A glove was required to continue. The noise at the ear seemed louder as well.

In the past, running the SBR with the Saker 5.56 and BCM bcg, while the handguard was warm, I never had to utilize a glove during sessions firing 300-400 rounds.

Has anyone else experienced the additional heat using the Gemtech bolt carrier?

[Slippers]

My first use of the Gemtech bolt carrier was limited to testing the premise of whether or not it did an adequate job of diminishing gas to the face. As previously stated, it did that well over the course of firing 20 rounds. Yesterday I went to the range to run drills and shot 200 rounds over the course of 30 minutes. I run a Saker 5.56 on a BCM 11.5" SBR. I noticed that the handguard and upper receiver heated up exponentially more with the Gemtech bolt carrier vs. the standard BCM. A glove was required to continue. The noise at the ear seemed louder as well.

In the past, running the SBR with the Saker 5.56 and BCM bcg, while the handguard was warm, I never had to utilize a glove during sessions firing 300-400 rounds.

Has anyone else experienced the additional heat using the Gemtech bolt carrier?

I doubt the carrier has any bearing on the handguard heat. Suppressed guns get hot, and the carrier isn't trapping anything or contributing to additional heat at the gas block.

[Singlestack Wonder]

Just got back from the range. fired 200 rounds over the course of 30 minutes with the BCM BCG in the same SBR. As before, handguard was warm but never so hot as to require a glove.

Is it possible that by venting gas at the supressed bcg allows for more hot gas to flow to the rear of the rifle, vs. the restricted flow with the normal bcg forcing more gas out the muzzle end?

[Slippers]

Just got back from the range. fired 200 rounds over the course of 30 minutes with the BCM BCG in the same SBR. As before, handguard was warm but never so hot as to require a glove.

Is it possible that by venting gas at the supressed bcg allows for more hot gas to flow to the rear of the rifle, vs. the restricted flow with the normal bcg forcing more gas out the muzzle end?

Hmm. I take back what I said about the carrier trapping something. The delayed unlocking that reduces the gas-to-face also means more gas is vented through the suppressor and out the front. More heat in the suppressor, which in turn means more heat in the barrel, and leads to a hotter handguard as the heat radiates from the barrel.

But, if you think about it, this is how it should be anyways. If you have excessive back pressure the gun isn't running optimally to begin with.