Low Mass Bolt Carrier Groups

[Huckleberry75]

I have been kicking around the idea of upgrading the bolt carrier group to a low mass option. I have looked at offerings from JP, Lantac, Rubber City, Fail Zero, Faxon and Brownells. It seems that the Brownells option comes in at the bottom of the price spectrum. Anyone have experience or an opinion on these? I will be running suppressed and already have an adjustable gas block, so that is squared away. Thanks in advance.

[A5BLASTER]

Skip all of those and get a stripped righttobear arms low mass bcg. If they have them on sale like normally the stripped lowmass is around 65 bucks.

I use them in all my rifles now.

[centerfire]

I have been kicking around the idea of upgrading the bolt carrier group to a low mass option. I have looked at offerings from JP, Lantac, Rubber City, Fail Zero, Faxon and Brownells. It seems that the Brownells option comes in at the bottom of the price spectrum. Anyone have experience or an opinion on these? I will be running suppressed and already have an adjustable gas block, so that is squared away. Thanks in advance.

There is no free lunch; to maintain reliability you will need to adjust the recoil spring and buffer weight. Unless you have some specific objective in mind you're just spending money and adding complication. I'm running a JP LMOS BCG in an AR308, I probably should have bought a standard weight JP BCG. JP's BCG are a work of art but I have had to swap out springs and buffers to get it right. The gas is also more critical because their seems to be a finer line for functionality. While the AR308 is not a AR15 Grendel the principle is certainly the same. Low Mass BCG's aren't an upgrade in my opinion.

[A5BLASTER]

There is no free lunch; to maintain reliability you will need to adjust the recoil spring and buffer weight. Unless you have some specific objective in mind you're just spending money and adding complication. I'm running a JP LMOS BCG in an AR308, I probably should have bought a standard weight JP BCG. JP's BCG are a work of art but I have had to swap out springs and buffers to get it right. The gas is also more critical because their seems to be a finer line for functionality. While the AR308 is not a AR15 Grendel the principle is certainly the same. Low Mass BCG's aren't an upgrade in my opinion.

It's less likely to need to do anything with the spring and buffer if you put a adjustable gas block on the rifle.

They are more or less meant to work together lowmass bcg and adjustable gas block.

I have standard weight carbine buffer and spring in my 16 inch and a jp gen 1 scs in my 20 inch. With adjustable gas on both I can take the scs out and drop in a standard rifle spring and buffer and it runs fine.

I can pull the carbine buffer and spring and drop in the scs in the 16 inch and it runs fine.

I then turn around and drop in a full mass bcg and run any combo of the spring/buffer or scs I want with lil to no gas adjustment.

This is all on ar15 grendels not sure if it would work the same on the ar10 308 pressure curve. If you don't have a adjustable gas block I would get one and try it out and see how it goes for you.

[Bigs28]

Faxon does not offer their low mass bcg in a 6.5 grendel bolt option. I called and asked if i could get one and they said from their testing they did not recommend their low mass carrier be used in a 6.5 grendel. I don't know why but that is the answer they gave me.

[centerfire]

It's less likely to need to do anything with the spring and buffer if you put a adjustable gas block on the rifle.

They are more or less meant to work together lowmass bcg and adjustable gas block.

I have standard weight carbine buffer and spring in my 16 inch and a jp gen 1 scs in my 20 inch. With adjustable gas on both I can take the scs out and drop in a standard rifle spring and buffer and it runs fine.

I can pull the carbine buffer and spring and drop in the scs in the 16 inch and it runs fine.

I then turn around and drop in a full mass bcg and run any combo of the spring/buffer or scs I want with lil to no gas adjustment.

This is all on ar15 grendels not sure if it would work the same on the ar10 308 pressure curve. If you don't have a adjustable gas block I would get one and try it out and see how it goes for you.

There's nothing really special about the SCS, it's a spring and weight just like any other buffer and spring combo of corresponding weights. You still have to cycle the action and feed rounds from the magazine. The platform is still confined to the reciprocating mass necessary to control recoil and function in all environments. As I said, there is no free lunch, if you reduce the weight of the carrier you will have to make up for it somewhere else, beit buffer spring, buffer weight, or gas. Lower gas means less rearward velocity of the standard carrier. Lower mass of the carrier means less inertia of the forward traveling BCG. Maybe it'll all work together in all conditions, and maybe it won't. Maybe you'll get a platform you have to fiddle with when you least expect it. Low mass carriers aren't an upgrade in my opinion (and experience) and certainly not a requisite to a soft shooting rifle.

[A5BLASTER]

There's nothing really special about the SCS, it's a spring and weight just like any other buffer and spring combo of corresponding weights. You still have to cycle the action and feed rounds from the magazine. The platform is still confined to the reciprocating mass necessary to control recoil and function in all environments. As I said, there is no free lunch, if you reduce the weight of the carrier you will have to make up for it somewhere else, beit buffer spring, buffer weight, or gas. Lower gas means less rearward velocity of the standard carrier. Lower mass of the carrier means less inertia of the forward traveling BCG. Maybe it'll all work together in all conditions, and maybe it won't. Maybe you'll get a platform you have to fiddle with when you least expect it. Low mass carriers aren't an upgrade in my opinion (and experience) and certainly not a requisite to a soft shooting rifle.

Well we will just have to agree to disagree. My rifles have been 100% reliable and soft shooting with lowmass bcg and adjustable gas no matter what buffer spring and buffer was in the rifle.

But like I stated without the adjustable gas the lowmass bcg isn't doing any good since they are meant to work together as a system.

[NOLAGT]

I agree from what I gather the Low mass BCG need the adj gas system to tune it to run good and lower felt recoil. I have a 2a armament Ti RBC (regulated bolt carrier) that im going to try out in my 2A 300blk pistol that does not have a adj gas block. This 2A RBC can be adjusted without taking it out and its stupid light. I sent them a email asking if I could use it for a Grendel...waiting on a reply....has anyone tried it before?

Faxon told me the same thing about there lite BCG not being suited for the 6.5g.

EDIT: 2A told me that I could swap on a 6.5 bolt and run there Ti regulated BCG in the Grendel.