JP Low Mass Carrier .308 great?

[new_cal_gun_guy]

Are JP Low Mass Carrier .308 great? Aren't they picky with ammo? is the less felt recoil really worth it for non competition use? what's the best BCG out there for a .308? any help apprieciated

thanks,

[CK_32]

Tag. Also interested in possibly picking up a JPLM BCG/Upped spring system.

[Norsemen308]

not worth it... if the carrier is lighter its going to hit the buffer harder, kinetic energy has to go somewhere...

get a hydraulic buffer or just buy yourself a heavy a2 rifle buffer for .308. with my hydraulic enidine recoil is less then a .223

[bsumoba]

Well, after about 300+ rounds through my 308 built with a JP LMOS BCG, adjustable gas block and captured recoil spring, I have some good comments for you guys

1) Make sure to get an adjustable gas block. You will need to "tune" your rifle slightly so that the BCG isnt slamming back at full force. You don't need as much gas to cycle the bolt since it is lighter than your standard 308 BCG steup. I went with the JP adjustable gas block. What I did when I found my load was turn the set screw in, then loaded one round and fired it and made sure the bolt lockup occurred. You will have to back it out if it does not cycle. Basically, you're looking to let in enough gas, just enough to cycle the rounds you're using. This is how you get minimized felt recoil. Couple that with a low lass bcg, the rifle will kick MUCH less than a standard .308 semi-auto.
2) Captured Recoil Spring is a nice to have. It does take the "twang" out of the rifle and it is more of a soild recoil. You could probably get away with a standard buffer and spring if you dont want to throw down the money for a captured recoil spring. I must say, if I had the money, that thing would be going in ALL my rifles after firing it.
3) The BCG has a very nice finish on it and is easy to clean. You can tell its well built. I have had zero issues with the bcg and setup in general. After 300+ rounds so far, the BCG finish is still as if its new. I have had minimal issues with the system in general (I say minimal because I did have a popped primer that wedged itself on the bolt key and seized the bolt until I "helped" it out by stripping it down. This isnt the gun's fault). The whole point of picky ammo is some ammo might/could be underpowered and may cause a failure but I have not experienced this. If you have underpowered ammo, you can simply adjust the gas block to allow for more gases to cycle the bolt.

Hope this helps and IMO, get it

Here is my setup. If you're interested in more details, PM me.



DPMS LR-308 A3 Flat Upper w/Delrin Forward Assist Plug
308 BCM Gunfighter Charging Handle - Medium
JP LMOS BCG
JP Enhanced Bolt
DPMS Cam Pin, Firing Pin, and Firing Pin Retainer Pin
JP 20" SuperMatch Barrel Black Teflon coated w/JP Large Comp
JP Black Thermal Dissapator w/ Rifle Length Gas Tube
JP Low Profile Adjustable Gas Block
JP Vtac XL Handguard w/15" Top Rail and Larue Rail Covers
POF Billet Lower w/CMMG LPK
KVM Rear Takedown Pin
Geissele SSA-E Trigger
MOE Rubber Grip
UBR Buttstock w/Strikeplate & Enhanced Rubber Buttpad
JP Captured Recoil Spring
Vortex PST 4-16x 50mm w/ Burris PEPR mount and Butler Caps

[IPSICK]

not worth it... if the carrier is lighter its going to hit the buffer harder, kinetic energy has to go somewhere...

get a hydraulic buffer or just buy yourself a heavy a2 rifle buffer for .308. with my hydraulic enidine recoil is less then a .223

This is why the JP LMOS BCG MUST be used with an adjustable gas block. The silent captured spring is a nice luxury item but not necessary.

But with just the adjustable gas block and the LMOS, a .308 AR will be a very soft shooter.

[bombadillo]

While I can't say for the .308, my .223 BCG and buffer were AWESOME! I could feel virtually no recoil when combined with the Bennie Cooley brake. They are worth every penny and the gas system does need to be adjustable for max potential to be reached.

[bsumoba]

^ Also forgot to mention. Couple all this and a JP brake and you can shoot hundreds of rounds in an outing and not feel a bit of pain at all.

[jdben92883]

^ Does any .308 semi result in pain? None of mine (SCAR, DPMS pattern, AR-10) do.

[IPSICK]

^ Also forgot to mention. Couple all this and a JP brake and you can shoot hundreds of rounds in an outing and not feel a bit of pain at all.

In terms of recoil, I can barely tell the difference between my .223 JP and my .308 JP.

[Sticky]

Well, after about 300+ rounds through my 308 built with a JP LMOS BCG, adjustable gas block and captured recoil spring, I have some good comments for you guys

1) Make sure to get an adjustable gas block. You will need to "tune" your rifle slightly so that the BCG isnt slamming back at full force. You don't need as much gas to cycle the bolt since it is lighter than your standard 308 BCG steup. I went with the JP adjustable gas block. What I did when I found my load was turn the set screw in, then loaded one round and fired it and made sure the bolt lockup occurred. You will have to back it out if it does not cycle. Basically, you're looking to let in enough gas, just enough to cycle the rounds you're using. This is how you get minimized felt recoil. Couple that with a low lass bcg, the rifle will kick MUCH less than a standard .308 semi-auto.
2) Captured Recoil Spring is a nice to have. It does take the "twang" out of the rifle and it is more of a soild recoil. You could probably get away with a standard buffer and spring if you dont want to throw down the money for a captured recoil spring. I must say, if I had the money, that thing would be going in ALL my rifles after firing it.
3) The BCG has a very nice finish on it and is easy to clean. You can tell its well built. I have had zero issues with the bcg and setup in general. After 300+ rounds so far, the BCG finish is still as if its new. I have had minimal issues with the system in general (I say minimal because I did have a popped primer that wedged itself on the bolt key and seized the bolt until I "helped" it out by stripping it down. This isnt the gun's fault). The whole point of picky ammo is some ammo might/could be underpowered and may cause a failure but I have not experienced this. If you have underpowered ammo, you can simply adjust the gas block to allow for more gases to cycle the bolt.

Hope this helps and IMO, get it

Here is my setup. If you're interested in more details, PM me.



DPMS LR-308 A3 Flat Upper w/Delrin Forward Assist Plug
308 BCM Gunfighter Charging Handle - Medium
JP LMOS BCG
JP Enhanced Bolt
DPMS Cam Pin, Firing Pin, and Firing Pin Retainer Pin
JP 20" SuperMatch Barrel Black Teflon coated w/JP Large Comp
JP Black Thermal Dissapator w/ Rifle Length Gas Tube
JP Low Profile Adjustable Gas Block
JP Vtac XL Handguard w/15" Top Rail and Larue Rail Covers
POF Billet Lower w/CMMG LPK
KVM Rear Takedown Pin
Geissele SSA-E Trigger
MOE Rubber Grip
UBR Buttstock w/Strikeplate & Enhanced Rubber Buttpad
JP Captured Recoil Spring
Vortex PST 4-16x 50mm w/ Burris PEPR mount and Butler Caps

Good feedback, thanks! I am about to bite the bullet and order up a JP barrel, BCG, gas block and muzzle brake to put on my precision 308 build. Thinking I will go a little longer on the barrel though.

How do you like the Vortex atop that build?

[new_cal_gun_guy]

How does the whole JP LMOS (BCG, Captured Spring, Bolt, Barrel, Adjust. Gas Block) handle surplus .308 ammo? Does it only eat fancy match ammo?

Thanks,

[bombadillo]

I've never seen them jam up with even the worst of ammo. I really enjoyed shooting PMC through my JP-15 upper.

[IPSICK]

How does the whole JP LMOS (BCG, Captured Spring, Bolt, Barrel, Adjust. Gas Block) handle surplus .308 ammo? Does it only eat fancy match ammo?

Thanks,

It will eat it no problem, but considering the investment why not feed it something a little better? I don't run steel cased or steel core through mine.

[new_cal_gun_guy]

I just want to make sure the JP LMOS will NOT force me to only use expensive ammo... I might have to run other ammo, you never know.

[bsumoba]

Good feedback, thanks! I am about to bite the bullet and order up a JP barrel, BCG, gas block and muzzle brake to put on my precision 308 build. Thinking I will go a little longer on the barrel though.

How do you like the Vortex atop that build?

Love it. Its not FFP, but for what I'm going to do with it, it works. I have a Bushnell Elite Tactical DMR 3.5-21x50 that I can swap onto it if ever I need FFP.

How does the whole JP LMOS (BCG, Captured Spring, Bolt, Barrel, Adjust. Gas Block) handle surplus .308 ammo? Does it only eat fancy match ammo?

Thanks,

ive tried steel cased and it ate up 10 rounds no problem. with that said, that was the only time i fed it steel cased. I reload and this rifle mainly sees reloads. With mine, Im running 175gr SMK under LC10 brass, CCI#34, and 43.5gr Varget and Im getting 1/2 MOA consistently, as long as i do my part as a reloader.