308 gas system length.

[XP1K]

Anybody ever run rifle length gas on a 16" 308 ?

If this is feasible I may give it a go. On my third large frame gasser now, started with a sig 716 then a 16" pof now an mk216 pws. The pws has been the best of the bunch and the one I still have but it still runs dirty and will still give you a face full of gas with some ammo. Even being a piston gun. And it's hard on cases. Decent shooter though.

I'm thinking I may try building one now. My goal is to be consistent .75-1 moa, which the pws does now, that is soft to shoot, which the pws is not, that won't be so hard on cases and won't give me a face full of gas.

I see several barrels offering mid length gas in a 16" and lilja offers an 18" with rifle length which I can cut to 16"

Looking at liljas drawing for their 18" it looks like that will only leave a little over 3" from muzzle to gas port.

Garands and m1a's gas ports are pretty close to the muzzle and they work just fine although they're not really a di system.

Somebody tell me why this won't work, I'll be searching for builder kits while I anxiously await the responses.

 

[Evintos]

It'll only work if the gas port is sized properly for the ammo pressure curve and reduced dwell time you would have with the rifle length gas. If you end up chopping the Lilja barrel, you may also have to drill the gas port a little larger as well (assuming it wasn't oversized to begin with).

 

[theLBC]

what kind of ammo are you shooting? superformance?

 

[jMarine]

I run it on my DPMS LR308 build. It’s a Noveske N6 barrel with their switchblock GB. I’ve had some issues with some ammo, one in particular, but I think it was more to do with that ammo brand and not the rifle. It shoots FGMM 175 like a sewing machine.

 

[XP1K]

what kind of ammo are you shooting? superformance?

Gold medal 168 was its favorite, and hornady black 168. The hornady is hotter, runs dirtier, federal premium with the 168 berger was the worst as far as gas in the face.

I had to send it back to pws for a new gas block and when it came back it seemed to favor gold medal 175's.

 

[theLBC]

Gold medal 168 was its favorite, and hornady black 168. The hornady is hotter, runs dirtier, federal premium with the 168 berger was the worst as far as gas in the face.

I had to send it back to pws for a new gas block and when it came back it seemed to favor gold medal 175's.

i was just asking because they don't recommend using it in shorter gas length systems.

 

[XP1K]

I run it on my DPMS LR308 build. It’s a Noveske N6 barrel with their switchblock GB. I’ve had some issues with some ammo, one in particular, but I think it was more to do with that ammo brand and not the rifle. It shoots FGMM 175 like a sewing machine.

What do your fired cases look like ? Mine usually come out looking like a di gun without an adjustable gas block.

These are the best of the bunch After the new gas block from pws. This one is three position, old one was four. Thought I had a pic of the bad ones, they were just about black. Ejection usually runs 1:30-2:00.

 

[XP1K]

i was just asking because they don't recommend using it in shorter gas length systems.

I didn't know that. Don't think I've ever shot any of it.

 

[theLBC]

I didn't know that. Don't think I've ever shot any of it.

i might try it just in case the extra velocity helps get out farther than fgmm.

Superformance in Gas Operated Firearms - Hornady Manufacturing, Inc

Background Superformance ammunition was developed in the Hornady ballistics lab utilizing state of the art test equipment in accordance with SAAMI (Sporting Arms and Ammunition Manufacturers Institute) guidelines for pressure, velocity and accuracy ut...

www.hornady.com

 

[TonyTheTiger]

Whatever Sig 716 that the Indian army adopted uses a rifle length gas system 16" barrel. There are other companies offering them as well as aftermarket barrels, just can't remember who off the top of my head. If 16" mid gas sucks in 5.56 I have to imagine it really sucks in 7.62.

 

[jMarine]

What do your fired cases look like ? Mine usually come out looking like a di gun without an adjustable gas block.
View attachment 7849354
These are the best of the bunch After the new gas block from pws. This one is three position, old one was four. Thought I had a pic of the bad ones, they were just about black. Ejection usually runs 1:30-2:00.

Yeah they come out pretty raunchy but I shoot mostly suppressed. I don’t really recall what they looked like unsuppressed. I’m still trying to tune the rifle with buffer weight and spring tension. Since the OSS can reduces the increased gas blowback known for running suppressed, the rifle does not wanna cycle properly when the GB is on the “suppressed” setting. I have to run it on the “unstressed” setting and now it’s way over gassed with the can mounted. I’ve got several springs and weights and a few boxes of FGMM 175 and Black Hills 168 amd plan on heading to the range tomorrow to try it get it tuned properly. I used to only shoot reloads in this rifle so I was able yo tune the load to the gun/can/GB combo but now I’m shouting facotry match stuff, it seems to be out of tune.

 

[XP1K]

Yeah they come out pretty raunchy but I shoot mostly suppressed. I don’t really recall what they looked like unsuppressed. I’m still trying to tune the rifle with buffer weight and spring tension. Since the OSS can reduces the increased gas blowback known for running suppressed, the rifle does not wanna cycle properly when the GB is on the “suppressed” setting. I have to run it on the “unstressed” setting and now it’s way over gassed with the can mounted. I’ve got several springs and weights and a few boxes of FGMM 175 and Black Hills 168 amd plan on heading to the range tomorrow to try it get it tuned properly. I used to only shoot reloads in this rifle so I was able yo tune the load to the gun/can/GB combo but now I’m shouting facotry match stuff, it seems to be out of tune.

Mine is shot suppressed 99% of the time. The brass in that pic was fired using my silencerco omega. Currently this pws is running the factory spring with an Xtra heavy carbine buffer. I ran a stiffer spring for a while but I got better accuracy with the stock spring/heavy buffer setup.

It's a drag to run that buffer setup because in stock trim this is the softest shooting 308 gasser I've had out of the three that I've owned. With the heavy buffer and or heavy spring it gets a sharp recoil impulse.

I'm trying to get a setup that's pleasant to shoot, shoots good and doesn't wreck brass because I reload mine as well.

What are you getting for velocity out of your handloads or the FGMM ? I'd have to go back and look buy iirc the 168's were running 2450-2480 I think. The hornady black usually a fuzz over 2500.

 

[GhostFace]

I've chopped 4 barrels down to 16 and 18 inches from longer lengths with RLGS, they all have worked like a top. You shouldn't have any problems considering it appears as if it yours has its gas port properly sized. I would not own or run a mid length gas system in .308 in 16 or 18 inches for anything....

 

[XP1K]

Whatever Sig 716 that the Indian army adopted uses a rifle length gas system 16" barrel. There are other companies offering them as well as aftermarket barrels, just can't remember who off the top of my head. If 16" mid gas sucks in 5.56 I have to imagine it really sucks in 7.62.

I've only found a couple aftermarket barrel options with rifle gas in a 16"

One is noveske, but I can't find them for sale. The other is an 18" lilja but I can part it off to 16" myself.

A lot of mid gas out there. I have a rainier select match 16" mid gas and their bcg from a previous pof di conversion I did. Maybe 100 rounds through it.

 

[jMarine]

Mine is shot suppressed 99% of the time. The brass in that pic was fired using my silencerco omega. Currently this pws is running the factory spring with an Xtra heavy carbine buffer. I ran a stiffer spring for a while but I got better accuracy with the stock spring/heavy buffer setup.

It's a drag to run that buffer setup because in stock trim this is the softest shooting 308 gasser I've had out of the three that I've owned. With the heavy buffer and or heavy spring it gets a sharp recoil impulse.

I'm trying to get a setup that's pleasant to shoot, shoots good and doesn't wreck brass because I reload mine as well.

What are you getting for velocity out of your handloads or the FGMM ? I'd have to go back and look buy iirc the 168's were running 2450-2480 I think. The hornady black usually a fuzz over 2500.

The recoil seems light to me but I don’t have any other gas 308 to compare it to. I do feel like it seems a little punchy like the BCG is slamming back, but again, I have nothing to compare it too. I’m running the JP silent capture spring. Right now it’s set up as a H2 but I have a tungsten weight to bring it to h3ish. I hope this slows my BCG down. I’ve been talking with another guy on here and that seems to be the issue I’m having with the factory loadings and my overgassing issue. My cases get pretty fucked up on factory loads when running suppressed and I’m sure it has to do with the fact I have to run my GB on the full open side (which I imagine Noveske has opened it up to optimize performance with this barrel length and gas system length) and the OSS can doesn’t produce enough gas blowback when in the reduced setting. It’s been interesting trying to tune it with this particular setup.

I’m like you though, I want this rig to shoot super smooth. It’s not bad at all to shoot now, it just kills my brass if it’s factory ammo. My handloads are tuned for it though.

If I remember correctly, my handloads were rather slow. I wanna say 2300ish with 175smk. But again, these were tailored to allow the rifle to function properly with open GB and OSS can with minimal damage to the case. I haven’t chronoed any factory ammo for it. I’ll likely do that tomorrow as I’m curious to see what FGMM 175s and BH 168s clock in at.

 

[TonyTheTiger]

I've only found a couple aftermarket barrel options with rifle gas in a 16"

One is noveske, but I can't find them for sale. The other is an 18" lilja but I can part it off to 16" myself.

A lot of mid gas out there. I have a rainier select match 16" mid gas and their bcg from a previous pof di conversion I did. Maybe 100 rounds through it.

Just have a custom barrel made. It'll be simpler and cheaper if you've gotta pay to cut down an 18". There are a lot of places that would be happy to do a 16" RLGS, Craddock is well respected around here, I've personally had great experiences with McGowen, X-Caliber and Mos-Tek for custom barrels.

Mid gas 16" barrels are common (in 5.56 anyway) because of parts standardization and because most guns/barrels are built for the lowest common denominator AR assembler. Not because they are the best choice.

 

[jMarine]

I've only found a couple aftermarket barrel options with rifle gas in a 16"

One is noveske, but I can't find them for sale. The other is an 18" lilja but I can part it off to 16" myself.

A lot of mid gas out there. I have a rainier select match 16" mid gas and their bcg from a previous pof di conversion I did. Maybe 100 rounds through it.

Stainless Micro-Switchblock® Barrel 7.62 x 51 | Noveske Rifleworks

Select a barrel length above to see barrel data

noveske.com

That’s a hefty price tag haha. I bought mine a few years back and it was 450 with the GB I believe.

It would probably be a lot cheaper to have one made for sure!

 

[ddavis]

Maybe not exactly what you are looking for but a data point nonetheless. The Savage MSR10 uses a proprietary gas system length that's 1.5" longer than mid-length in a 16" 308. I guess they didn't feel comfortable going all the way to rifle length. That combined with an excellent adjustable gas block makes it shoot really smooth. Running it with a can that has pretty low backpressure I still get sooty brass. I haven't found a way to avoid that yet.

 

[TonyTheTiger]

The Savage MSR10 uses a proprietary gas system length that's 1.5" longer than mid-length in a 16" 308.

I wish there was a standardized intermediate length gas. The 2 I have and the ones I see most commonly are 2" longer than mid, so 1.5" shorter than rifle. If they could just pick a number and stick with it it might finally catch on. There's no doubt that it's a significant upgrade from mid length.

 

[jMarine]

I wish there was a standardized intermediate length gas. The 2 I have and the ones I see most commonly are 2" longer than mid, so 1.5" shorter than rifle. If they could just pick a number and stick with it it might finally catch on. There's no doubt that it's a significant upgrade from mid length.

Yeah I don’t understand why more aspects of the large frames can’t be standardized! It’s frustrating sometimes. But that’s part of the game. Hence the reason why the windshield wiper section is an aisle long!

 

[XP1K]

Just have a custom barrel made. It'll be simpler and cheaper if you've gotta pay to cut down an 18". There are a lot of places that would be happy to do a 16" RLGS, Craddock is well respected around here, I've personally had great experiences with McGowen, X-Caliber and Mos-Tek for custom barrels.

Mid gas 16" barrels are common (in 5.56 anyway) because of parts standardization and because most guns/barrels are built for the lowest common denominator AR assembler. Not because they are the best choice.

I may look more into the custom barrel route if I commit to go down this path. I can cut, crown and thread the muzzle myself so I'm not out anything but time there. The lilja is $550 so I'm sure there's probably something ready to go somewhere in that price range. I will look into it more tonight. I'm working nights so I've got free time between welds.

 

[XP1K]

What's everybody preference on recievers ?

I found a set of seekins in stock from Joe bobs. I was leaning towards seekins or aero. Local shop has a stag set on hand. They are an armalite pattern that uses dpms barrels and handguards. Stag stuff has always seemed well made to me.

 

[TonyTheTiger]

FWIW, X-Caliber has a 20% off sale starting tomorrow. That puts a custom AR10 barrel around $300 before add ons.

Edit to add: both McGowen and Mos-Tek will do custom gas lengths if your nervous about going rifle length but still want longer than mid.

 

[jMarine]

FWIW, X-Caliber has a 20% off sale starting tomorrow. That puts a custom AR10 barrel around $300 before add ons.

Edit to add: both McGowen and Mos-Tek will do custom gas lengths if your nervous about going rifle length but still want longer than mid.

Good to know!

 

[msgriff]

The Wilson Combat 16" .308 Ranger uses their intermediate length gas system. 13.25" gas tube compared to the more common 11.75" mid-length.

 

[Norther]

Criterion lists a 16” rifle gas barrel. Out of stock right now.

Link

 

[TapRackBang]

Criterion is good to go, I have an 18 inch rifle gas I like. The 16 should work fine as well.

 

[Sincerd]

Tubs spring would help. A5 or 308 receiver extention with a5 buffer or heavy buffer a5. Slash XS I think it is.

If you don't mind an additional failure point, amphibian shows pretty solid evidence for the merit of rb5005 hydraulic buffer in place of a5.

I think BRT has restricted gas tubes for standard barrels now.

Many options and I think you will have to tune whatever you get if you want it to shoot soft as 308 with can. I can get a 16" mws shooting softer than a 16" 556 with just a few parts.