I am running an Lmt mws 308 16 inch barrel with an aac 7.62 sbn6 can. Ubr gen 2 stock. I’ve tried multiple combinations of buffer and buffer springs and have finally resorted to using an adjustable gas key to control over gassing I was wondering if going to the 18 inch barrel would make a significant difference due to the extended gas system
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Lmt over gassed
- Thread starter Joshua1:9b
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I put a JP adjustable gas block on mine. I can shut the gas all the way off.
My biggest gripe with LMT is every one of their barrels is overgassed it seems or at least the ones I own.
Unless you cut the 18" rifle length barrel to 16" it's probably going to be overgassed as well.
Slash xh buffer should help. Someone here drilled and tapped their factory LMT gas block and made it adjustable.
From my understanding aftermarket blocks won't fit right due to oddball port spacing in relation to the shoulder because of lmt's angled port.
The best solution for me has been having Marvin Pitts sleeve standard barrels to fit my MRP and mws rifles.
Unless you cut the 18" rifle length barrel to 16" it's probably going to be overgassed as well.
Slash xh buffer should help. Someone here drilled and tapped their factory LMT gas block and made it adjustable.
From my understanding aftermarket blocks won't fit right due to oddball port spacing in relation to the shoulder because of lmt's angled port.
The best solution for me has been having Marvin Pitts sleeve standard barrels to fit my MRP and mws rifles.
I run the heavy buffer. You can check out Black River tactical. BRT makes gas tubes and inserts to limit gas. I have one on my 16 inch and it runs like a champ. He made some prototype gas tubes for the MWS, ask them about those.
I believe mine came with a H3 buffer I bought a heavy buffer from slash that was 6.5 ounces didn’t do the trick so I went to an A seven style tube and bought another buffer that I got up to 8.3 ounces
Just got done shooting it after putting the 8.3 ounce buffer back in been running it with another gun
Got the gas adjusted to cycle fine through approximately 12 rounds but still not ready to risk my life on it cycling
Air hammer. But, it was not on that tight. Hammer and punch would do the trick.
Air hammer. But it was not that tight. Hammer and punch would do the trick.
Air hammer. But it was not that tight. Hammer and punch would do the trick.
Thanks that is nice to actually see. I’m wondering with the 16 inch barrel, having the gas block under the rail, if I would be able to access the set screw and adjustment screw. I’ll keep playing with my gas key for now but may switch over if I keep having issues
Did you remove the gas block first before drilling? Was it a pain to get back on? What did you tap it to?
Rifle length gas systems Run smoother than the gas system LMT uses so going to an 18 might work out for you. I know that my GEMTECH GMT 300WM would run fine with my 18 SS 308 and my 20 inch 6.5CM, but was pretty violent with my 13.5 and 16 inch barrels.
I ended up mounting my Sandman K on my 13.5, and its great, zero issues
With that being said, I think that many of us may be approaching the matter from the wrong side. In regards to LMT barrels being over-gassed, yes and no. The LMT was designed to basically fire any ammo and any environment, this ranges from Radway Green Machine gun ammo to Lake City 175's. so in order to get 147 Machine gun ammo to work at -60 some sacrifices need to be made, such as over gassing the system.
So when these rifles are shot on the civilian side of the house, people mount silencers from companies that historically chased maximum Db reduction, and as a result the gas pressure/ bolt velocity goes through the roof. and the system is no longer reliable.
In an attempt to fix the matter, people introduce more moving parts into the system with varying levels of quality control, in order attain a functional weapon.
So rather than take than changing out any of the weapons core components, I think that it would be both far more effective just running a can that was designed for minimal back pressure. Surefire, Knights, LMT, Dead Air, OSS and many other manufactures have silencers that have been engineered to have a minimal impact of the operating system.
You will then have a weapon system that is just as reliable suppressed or suppressed with any ammo.
I think that adjustable gas systems have their place, but i am not sure I would feel too confident with a clamped on hobby grade gas block, that is adjusted down to the ragged edge of reliable function just to be able to run an older/high pressure can.
people will spend 500 to a 1000 dollars fucking around with spare parts, and custom barrel work, and not give two seconds thought to a new can that would solve the issue.
Horrible Silencer/Barrel Combo
Awesome Silencer/Barrel Como
They are over gassed with out a suppressor. True, LMT set them up for battle and reliability. But they are set up to run with out a suppressor. If you want to run a suppressed with out being even more over gassed, you need to turn it down.
And, yes a rifle length gas system would help. But, it is still going to be over gassed.
And, yes a rifle length gas system would help. But, it is still going to be over gassed.
Curious,
Why would you choose to turn down the gas/modify they system rather just run a can with high flow through/low back pressure that has little impact on the system?
You are sacrificing unsuppressed reliability as well as durability all to run a high pressure can.
I get the band aid solutions for states that do not allow silencers, but for most case, get the right part for the job
Adding a suppressor increases back pressure. That's how they work. Some less than others, but that is how they work. If you add a suppressor to a already over gassed system it will be even more over gassed. There is no magic can that does not increase back pressure.
LMT built their system to run unsuppressed with maximum reliability under a wide set of conditions.
LMT built their system to run unsuppressed with maximum reliability under a wide set of conditions.
LMT's run harder than most 308 AR's but i am not sure i would considering them over gassed. They are significantly more reliable than most 308 AR's, and unlike alot of commercial grade 308's they dont beat them selves apart.
They have worked fine for years down range with no mods by using surefire cans. Thats part of the reason the L129 is issued with a Surefire mount. They just work.
If the solution to running LMT's suppressed was solved 10 years ago, I am not sure why we are trying to reinvent the wheel. Just get a can the works and be done with it.
If you want to run a hobby grade can, get a PSA10 and go to town
They have worked fine for years down range with no mods by using surefire cans. Thats part of the reason the L129 is issued with a Surefire mount. They just work.
If the solution to running LMT's suppressed was solved 10 years ago, I am not sure why we are trying to reinvent the wheel. Just get a can the works and be done with it.
If you want to run a hobby grade can, get a PSA10 and go to town
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Mine has head trouble running with a surefire 762rc....
It can get real nasty with malfunctions and mangling brass with some loads. All that testing and figuring was likely done with milspec loads. I that doesnt mean it is optimized for the plethora of commercial and handload pressure curves.
Adjustable gas blocks, keys and carriers are cheaper, easier, and faster than buying 1/2 a dozen cans hoping one works.
We're not grunts. It doesn't need to be idiot proof.
@bigjake83 I spent 45 minutes looking for that pic!! Though for some reason I thought it was Spife that posted it. That's the way I would do it if I was determined to have an adjustable gas block on my MWS.
You mention the words "can, and hand load"
If you are running red line loads or hornady super performance, trying to get every last bit of velocity from that case, you are going to have issues, loaded hot enough, a 308 gas gun will mangle gas without a can. if Velocity is that critical for your use, it might be time to considering a more efficient cartridge.
If you are mangling brass, that's your first hint is start dialing it back, or finding a new powder/bullet combo.
your hammering a 308 to get less effective range as a mild 6.5. It goes back to the questions what are we really trying to do here and using the right tool for the job.
We don't need to kill ourselves to make this stuff work.
2425fps for a 175/178 from a 16" ar is hot? That's the point where mine would start choking.
Eta: from what I've seen the people that chop 18" rl barrels to 16", 16" to 13.5 and still run just about anything without a can and no port work it's a sign they're overgassed. I want to say one of the LMT guys put on FB that they chopped a 20" 5.56 to 16" and it ran fine without touching the gas port.
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BRT gas tubes for the MWS are the easiest fix. Essentially works as port insert but it's just a gas tube with a smaller opening of your choice in size. Over on M4C they have a big following. I was an early tester for the 5.56 gas tubes. Now they do them for the MWS. That's what I would do. And one roll pin for the install.
Tac 40.5-41gr iirc LC brass
Stovepipe/FTE stoppages. Runs fine unsuppressed but not so much with can. Extractor orings, spring upgrades etc help. Worse with higher charges. Typical overgassed sypmtoms.
I believe 44gr of varget with a 165 btsp in fc brass had some issues as well and mangled the brass pretty good. It was a pig hunting load so I used fc brass so I wouldn't mind loosing them.
It's been a while since I've used that barrel.
It's been a while since I've used that barrel.
hmmmm,
did you try any tac loads at 39 grains or Varget at 42ish? If so how did the gun run?
I never used tac but in term of case capacity with Varget, I think that i recall that 44 grains is getting a little close to a compressed load with the old 178's. its been a while since i loaded with varget.
did you try any tac loads at 39 grains or Varget at 42ish? If so how did the gun run?
I never used tac but in term of case capacity with Varget, I think that i recall that 44 grains is getting a little close to a compressed load with the old 178's. its been a while since i loaded with varget.
I have a 16' LMT MWS 308 with SWR suppressor DI. Wish it was an adjustable piston... The gas rings have blown out on the bolt, but shoots just fine without them; just a little more carbon buildup... Hope the new gas block helps.
To make it cycle suppressed I had to crank it so far down it wouldn’t run with out the supressor. I gave up on it.
Lmt 308
16 inch barrel
A5 buffer tube
8.5 ounce slash carbine length heavy buffer
With my h3 buffer I’m ejecting about 1 o’clock. With the 8.5 ounce buffer I’m ejecting about 2 o’clock. When you attach the supressor it’s like putting regular gas in a diesel truck. I’ve given up on that.
What is the best 308 heavy rifle length spring to help slow this down. Looking at tubb flat wire spring.
16 inch barrel
A5 buffer tube
8.5 ounce slash carbine length heavy buffer
With my h3 buffer I’m ejecting about 1 o’clock. With the 8.5 ounce buffer I’m ejecting about 2 o’clock. When you attach the supressor it’s like putting regular gas in a diesel truck. I’ve given up on that.
What is the best 308 heavy rifle length spring to help slow this down. Looking at tubb flat wire spring.
I have a higher pressure can that is incompatible with my 16 inch CL and 13.5 inch 308 barrels, The same can on my 18 inch 308 or 20 inch 6.5cm has no issues.
If you are going to use a higher pressure can, i would recommend a new gas tube from black river tactical. Of all the solutions for overgassing, I think this is one of the better options if getting a low pressure can is not in the cards.
https://blackrivertactical.com/WP/BRT-EZTUNE-Gas-Tube-LMT-MID-p148504128
I’m actually selling the can to my friend who has a scar. And I have recently got access to the field behind me to shoot so I can shoot over 1000 yards from my back porch! With is the possibility of sniper school coming up I am looking at going to the 18 or 20 inch barrel which hopefully will fix my problem.
I was looking at the gas tube option but I’ve heard that you get port hole erosion pretty severely when the only thing restricting the Gas is a thin orifice on the gas tube. Have you ran into any problems with that.
I was looking at the gas tube option but I’ve heard that you get port hole erosion pretty severely when the only thing restricting the Gas is a thin orifice on the gas tube. Have you ran into any problems with that.
I would give them a call and ask, I seriously doubt anybody has real data on the matter. I have high pressure and low pressure cans so don't have any gaming issues running the factory tube
I bought the gun used but I believe everything on it was stock at the time. it has the single ejector on the bolt face
Well there you go. Other people’s experience may vary but I had pretty frequent fte and ejector swipe issues with my early single ejector gun. The double ejector bolt cured every issue
This is wacha want https://blackrivertactical.com/WP/Adjustable-Gas-Drive-c6464009
Then buy an oss/huxwrx - it will run almost identically with and without the can.
I figured that may help. but I didn’t know if it would change the ejection angle as well if it actually is able to eject it faster or just more reliably
It’s night and day difference with the dual ejector bolt. I want to say mine went from kind of erratic forward ejection to throwing cases 15-30ft straight to 3 o’clock.
I did have some success with the old bolt by installing a jp extractor and changing the spring/o-ring/buffer.
