LMT .308 MWS

Mitu

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So, this is pretty disappointing. I went to go test out my new rifle (assembled from a MARS-H lower, MLOK upper, LMT BCG, and 16” SS barrel). It shot great, but the bolt hold open wasn’t working. Felt like it wasn’t getting the full movement, so I pulled it apart and I see this:

50E03565-320F-4639-990B-92BC15F4903E.jpegA34ACF54-5422-4115-B062-6982D88168AF.jpeg6BDAB459-D0B5-4DFB-8488-B015D3377AE8.jpeg
Looks like it’s not setting right. Guess my best bet is to get a hold of LMT?
 

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tvalks

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Nov 29, 2019
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So, this is pretty disappointing. I went to go test out my new rifle (assembled from a MARS-H lower, MLOK upper, LMT BCG, and 16” SS barrel). It shot great, but the bolt hold open wasn’t working. Felt like it wasn’t getting the full movement, so I pulled it apart and I see this:

View attachment 7401272View attachment 7401273View attachment 7401276
Looks like it’s not setting right. Guess my best bet is to get a hold of LMT?
Is it a factory complete lower or a stripped lower?All LMT parts? Mine has a tiny amount of wear in some of the same areas (not as much as yours) but nothing had an effect on function on a Complete factory gun.
 

Mitu

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Is it a factory complete lower or a stripped lower?All LMT parts? Mine has a tiny amount of wear in some of the same areas (not as much as yours) but nothing had an effect on function on a Complete factory gun.
All LMT parts minus the trigger and the stock/grip. MARS-H lower, LMT lower parts kit, MLK MWS Upper, LMT 308 BCG. Assembled by my gunsmith. When the upper is off the rifle, the bolt hold back has full range of motion. When the upper is attached, no dice.
 

Choid

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is it possible he put it in with a pin, like a normal lower, rather than using the screw provided?
 

Mitu

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is it possible he put it in with a pin, like a normal lower, rather than using the screw provided?
So, the lower already came with the ambi parts (mag release, bolt release, and selector) loosely installed. He just tightened and added the rest of the lower parts kit.
 

CrabsandFootball

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Putting together the last pieces for a full LMT 20" 6.5CM MWS.

Trying to decide on a stock. LOVE the Sopmod. Is it really worth running the PRS or the LMT precision stock? Is the PRS a better stock than the LMT?
 

Puget Shooter

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Putting together the last pieces for a full LMT 20" 6.5CM MWS.

Trying to decide on a stock. LOVE the Sopmod. Is it really worth running the PRS or the LMT precision stock? Is the PRS a better stock than the LMT?
Personal preference. It takes about 30 seconds to swap between Sopmod and LMT DMR.
 

CrabsandFootball

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Going to be shooting mostly from a Tripod and some from a Bipod. Woried the DMR stock would be to unweildy and I have heard its loose and not as tight at the Magpul?
 

Gasgun

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Going to be shooting mostly from a Tripod and some from a Bipod. Woried the DMR stock would be to unweildy and I have heard its loose and not as tight at the Magpul?
I use the DMR. It isn’t loose. I don’t find it unwieldy.
I shoot mostly off of a bipod.
I have no experience with the PRS.
 

BEJ762

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Going to be shooting mostly from a Tripod and some from a Bipod. Woried the DMR stock would be to unweildy and I have heard its loose and not as tight at the Magpul?
I run both.

The LMT DMR locks up solid, is shorter in length but has adjustment if you want a long stock. I also feel it is a little lighter than the magpul.

The only thing the magpul has going for it in my option is the adjustable butt pad. Other that that, it is too long and heavy.
 

Lucky Se7en

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The Magpul does seem to be a little more solid if you are using the adjustments, I wouldn’t say the LMT is a problem though. The butt pad also has more cushioning on the Magpul which should be appreciated by anyone who has broken their collarbone. I like the additional width for the cheek weld on the LMT stock, I’ve been trying both out lately and don’t have a hands down favorite but am leaning towards the Magpul.
 

Mitu

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Dec 21, 2009
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So, this is pretty disappointing. I went to go test out my new rifle (assembled from a MARS-H lower, MLOK upper, LMT BCG, and 16” SS barrel). It shot great, but the bolt hold open wasn’t working. Felt like it wasn’t getting the full movement, so I pulled it apart and I see this:


Looks like it’s not setting right. Guess my best bet is to get a hold of LMT?
FYI, in case anyone is interested, spoke to LMT this week. Sounds like they’ve had this issue a couple of times before, has to do with the bolt catch riding too high. They’re going to send me a replacement bolt catch.
 

Starman_Dan

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Hello! I recently had my barrel cut down from 16" to 14.5" and pinned and welded. In the past I had a 13.5" barrel than ran flawlessly with my 8.5oz XH Buffer and spring.

I was able to take it out to the range today and was having some serious cycling issues where the carrier would either not eject or would barely travel past half the length of the next round. I would say it cycled about 50% of the time. The buffer is, obviously, the likely culprit here and I am looking to replace it as soon as possible and wanted some input on the way to go with this.

I have the standard MWS buffer tube and my current spring is the one provided with the XH Buffer from Slash's. I was looking at the Noveske H3 buffer and wanted to know if the spring from slashes would be good with this or if there is another spring I should consider? I would go for the LMT stock spring/buffer, but I cannot find them independent of the "buffer kit".

I do have a Sandman-S in jail right now that I intend on running 100% of the time on my MWS and will hang onto the XH buffer to run with that.

Thank you very much for the help!
 

ClangClang

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I was able to take it out to the range today and was having some serious cycling issues where the carrier would either not eject or would barely travel past half the length of the next round. I would say it cycled about 50% of the time. The buffer is, obviously, the likely culprit here and I am looking to replace it as soon as possible and wanted some input on the way to go with this.
You're probably on the right track. Your current Slash spring will probably work just fine with the Noveske H3 (good choice for a cut down 16"), but given how cheap another spring is, the smart move is to have a dedicated spring for each buffer. Aside from the standard .308 LMT spring, the other spring I really like is David Tubb's Flatwire 308 spring. I probably have 5 of them or so. They've tamed recoil, improved ejection consistency, and removed the "sproing" noise in every gun I've tried them in. I pretty much use Tubb springs exclusively at this point aside from my dedicated competition guns which have the JP SCS.
 
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Starman_Dan

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Thank you very much for the help! I just wanted to follow up because I also got in touch with Clint from Slash's heavy buffers. He said that the H3 should run perfectly fine with his provided spring and the can should fix my XH issues.
I just picked up an H3 buffer, LMT Spring, and a flatwire spring so I plan on going to the range at the end of this week and just test out some different combinations to see what my MWS likes the best. Also got a few new to me SR25 mags so it'll be a good time to make sure they all run properly as well.

Update: Flatwire spring and H3 run great in it, shoots nice and soft with m118lr!
 
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Fire4EffectCA

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I have all three. The Magpul PRS is rock solid, but I do prefer the LMT DMR check rest. The LMT DMR lock up is no worse than the LMT Sopmod, but there is no extension limit so you can end up removing the stock accidently in the field when you extend it.

I currently have the Magpul PRS installed on my MWS. Like you, I have also built up a 6.5CM upper for my MWS.



Putting together the last pieces for a full LMT 20" 6.5CM MWS.

Trying to decide on a stock. LOVE the Sopmod. Is it really worth running the PRS or the LMT precision stock? Is the PRS a better stock than the LMT?
 

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League 4

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Jun 11, 2020
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Quick question. So my LMT MWS came with a 16" 1:11.25 twist rate 7.62x51mm barrel, and I just recently bought a dimpled barrel without even thinking of the twist rate, and it's a 1:10 .308 marked barrel. 95% of my long gun shooting has been with a KAC M110 shooting M118LR with their 1:11.25 barrel, and the ammo that I use most with my LMT MWS is 175gr M118LR.... So, would I even notice much of a difference in twist rate 800 meters and in? I dont do any extreme long range shooting, would I even notice much of a difference with the 1:10 twist barrel? The best info I've been able to find online has basically just said the 1:10 would be "less optimized" and very little more than that.
 

Lurp06x

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Anyone who ordered a Lmt MWS rifle back in February get there’s in yet? I have a month and a half left till the quoted estimated ship date. It’s just along time to wait.
 

flyright

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Quick question. So my LMT MWS came with a 16" 1:11.25 twist rate 7.62x51mm barrel, and I just recently bought a dimpled barrel without even thinking of the twist rate, and it's a 1:10 .308 marked barrel. 95% of my long gun shooting has been with a KAC M110 shooting M118LR with their 1:11.25 barrel, and the ammo that I use most with my LMT MWS is 175gr M118LR.... So, would I even notice much of a difference in twist rate 800 meters and in? I dont do any extreme long range shooting, would I even notice much of a difference with the 1:10 twist barrel? The best info I've been able to find online has basically just said the 1:10 would be "less optimized" and very little more than that.
Short answer is - no. I know several shooters that prefer 1/10 over 1/11.25 especially for the 175's. There will be more of a difference in just the "luck of the draw" between the 2 barrels accuracy wise.
 
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Fire4EffectCA

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The Magpul does seem to be a little more solid if you are using the adjustments, I wouldn’t say the LMT is a problem though. The butt pad also has more cushioning on the Magpul which should be appreciated by anyone who has broken their collarbone. I like the additional width for the cheek weld on the LMT stock, I’ve been trying both out lately and don’t have a hands down favorite but am leaning towards the Magpul.

Here is the Magpul Gen 3 PRS stock on my LMT MWS. It’s solid and I don’t find it unwieldy for my purposes. I do prefer the monopod rail on the earlier generation with the rail cover to this configuration.
 

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Fire4EffectCA

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Here is the Magpul Gen 3 PRS stock on my LMT MWS. It’s solid and I don’t find it unwieldy for my purposes. I do prefer the monopod rail on the earlier generation with the rail cover to this configuration.

Here is the early Magpul PRS stock with monopod rail cover on an AR-15.
 

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MPD142

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Quick question. So my LMT MWS came with a 16" 1:11.25 twist rate 7.62x51mm barrel, and I just recently bought a dimpled barrel without even thinking of the twist rate, and it's a 1:10 .308 marked barrel. 95% of my long gun shooting has been with a KAC M110 shooting M118LR with their 1:11.25 barrel, and the ammo that I use most with my LMT MWS is 175gr M118LR.... So, would I even notice much of a difference in twist rate 800 meters and in? I dont do any extreme long range shooting, would I even notice much of a difference with the 1:10 twist barrel? The best info I've been able to find online has basically just said the 1:10 would be "less optimized" and very little more than that.

The 1:10 marked barrel if factory LMT is going to be a Chrome Lined Barrel where the 1:11.25 would be a stainless barrel. All of the CL 1:10 barrels I've had shot pretty decent but the Stainless barrels do out perform them generally.
 

LMT/556

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Other that that, it is too long and heavy.
This. I tried a Gen 3 PRS on a small frame AR, it was as long as an A2 before adjusting it out, AND about 2lbs(heavy). Sent it back. I prefer the SOPMOD (LMT or B5), but have the DMR on both large and small frame LMTs, like them well enough to keep them.
 

Fire4EffectCA

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Recommended LMT MWS Modifications

After my recent trip to the range I have decided to address over gas issues and cartridge case damage with the following modifications. My rifle is not suppressed and I do not run a brake.

Install an adjustable gas key. I see there are at least two manufacturers, Rubber City Armory and ADIGS. Are there advantages over one compared to the other?

Break the pointed edges at the rear of the barrel extension lugs. Mine are cutting two deep parallel gouges on the case neck during ejection. I have found several discussions regarding this issue, but none clearly explain how to modify the rear of the barrel extension lugs. I would imagine easing the edge would correct the problem, but what are the proper contours and the best tools to achieve it? I found an inexpensive source for AR-10 barrel extensions and I think I will order one or two to practice on.

Remove a coil from the ejector springs to correct case dents from cases hitting the case deflector. I see some are just adding a piece of Velcro to the case deflector. Any recommendations here?

My rifle has the stock H3 buffer and stock LMT spring. Are there any advantages to upgrading these components?

BTW, I installed a POF roller cam pin for my new MWS upper and BCG and the wear pattern looks much better than my original MWS upper and BCG with factory LMT cam pin.
 

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GUNNER10

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Recommended LMT MWS Modifications

After my recent trip to the range I have decided to address over gas issues and cartridge case damage with the following modifications. My rifle is not suppressed and I do not run a brake.

Install an adjustable gas key. I see there are at least two manufacturers, Rubber City Armory and ADIGS. Are there advantages over one compared to the other?

Break the pointed edges at the rear of the barrel extension lugs. Mine are cutting two deep parallel gouges on the case neck during ejection. I have found several discussions regarding this issue, but none clearly explain how to modify the rear of the barrel extension lugs. I would imagine easing the edge would correct the problem, but what are the proper contours and the best tools to achieve it? I found an inexpensive source for AR-10 barrel extensions and I think I will order one or two to practice on.

Remove a coil from the ejector springs to correct case dents from cases hitting the case deflector. I see some are just adding a piece of Velcro to the case deflector. Any recommendations here?

My rifle has the stock H3 buffer and stock LMT spring. Are there any advantages to upgrading these components?

BTW, I installed a POF roller cam pin for my new MWS upper and BCG and the wear pattern looks much better than my original MWS upper and BCG with factory LMT cam pin.

While I know that are some people out that that have done the adjustable gas keys, there have been enough post about adjustable gas systems that at best can be concluded as wonky. With that being said I really like the concept behind the black river tactical EZtune gas tubes, where the ports in the gas tube are sized to reduce gas and there are no moving parts. No worrying about gas key staking or gas leakage, its just a gas tube change.

My 13.5 over was very over gassed especially with a more restrictive can and if I was to address the overgassing with a Low pressure can and 9oz XH buffer and spring combo from Slash. I really like how it runs both suppressed and unsurpressed. My 20 inch 6.5cm shoots very nice, even with a more restrictive can. With that being said, I would consider ordering one of their custom gas tubes to kind of experiment with my 13.5 and go back to an H3 buffer inorder to reduce reciprocating mass.

In regards to the sharp edges that are scaring your brass, by chance have you reached out to LMT about the matter, they should be able to polish those edges
 
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Fire4EffectCA

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While I know that are some people out that that have done the adjustable gas keys, there have been enough post about adjustable gas systems that at best can be concluded as wonky. With that being said I really like the concept behind the black river tactical EZtune gas tubes, where the ports in the gas tube are sized to reduce gas and there are no moving parts. No worrying about gas key staking or gas leakage, its just a gas tube change.

My 13.5 over was very over gassed especially with a more restrictive can and if I was to address the overgassing with a Low pressure can and 9oz XH buffer and spring combo from Slash. I really like how it runs both suppressed and unsurpressed. My 20 inch 6.5cm shoots very nice, even with a more restrictive can. With that being said, I would consider ordering one of their custom gas tubes to kind of experiment with my 13.5 and go back to an H3 buffer inorder to reduce reciprocating mass.

In regards to the sharp edges that are scaring your brass, by chance have you reached out to LMT about the matter, they should be able to polish those edges

Thank you for mentioning the Black River Tactical EZtune gas tubes. I went to their site to educate myself on their product, but it is not clear to me how you determine which size to order for a 20" 7.62 or 6.5 CM barrel.

Regarding the LMT barrel extension trashing fired brass. I spoke with LMT and they consider the damage to the brass as normal.
 

SFree

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Call Black River Tactical and talk to Clint, he’ll ask what conditions you are experiencing, then give you recommendations for your intended purposes for the rifle. Most likely will be exactly what ya need.
 
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Fire4EffectCA

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Call Black River Tactical and talk to Clint, he’ll ask what conditions you are experiencing, then give you recommendations for your intended purposes for the rifle. Most likely will be exactly what ya need.

I will give them a call tomorrow . . . Thanks !!!
 

Fire4EffectCA

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I ordered the BRT EZTUNE today. They said I don’t need to upgrade the buffer and buffer spring.

 
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Sincerd

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I just installed a BRT gas tube into a 13.5 p/w. With an oss helix qd suppressor And....


It was perfect. Less recoil than an unsuppressed 16" stock SR-25. Much less actually. Both used with a tubbs flatwire and lmt H3

Brass looks perfect except 2 very small scratches on the brass from feed ramps. May eventually polish those out. Or maybe let the gun break in.
 

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Jsp556

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I ordered the BRT EZTUNE today. They said I don’t need to upgrade the buffer and buffer spring.

When you get it, measure the port size, remove your factory gas tube, then drill the measured port size in the stock tube. Now you have 2.
 

Sincerd

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When you get it, measure the port size, remove your factory gas tube, then drill the measured port size in the stock tube. Now you have 2.
But the whole point is that the new one would be smaller. These are over gas not under gassed
 

Jsp556

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But the whole point is that the new one would be smaller. These are over gas not under gassed
I think you’re missing my point. Lmt tubes are straight. Drill the reduced port size in the “top” of the factory tube and run it upside down. Matter of fact, drill the new one straight through so it’ll last twice as long. The port in the tube is going to erode and increase in size resulting in the over gas condition returning.
 

Sincerd

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Recommended LMT MWS Modifications

After my recent trip to the range I have decided to address over gas issues and cartridge case damage with the following modifications. My rifle is not suppressed and I do not run a brake.

Install an adjustable gas key. I see there are at least two manufacturers, Rubber City Armory and ADIGS. Are there advantages over one compared to the other?

Break the pointed edges at the rear of the barrel extension lugs. Mine are cutting two deep parallel gouges on the case neck during ejection. I have found several discussions regarding this issue, but none clearly explain how to modify the rear of the barrel extension lugs. I would imagine easing the edge would correct the problem, but what are the proper contours and the best tools to achieve it? I found an inexpensive source for AR-10 barrel extensions and I think I will order one or two to practice on.

Remove a coil from the ejector springs to correct case dents from cases hitting the case deflector. I see some are just adding a piece of Velcro to the case deflector. Any recommendations here?

My rifle has the stock H3 buffer and stock LMT spring. Are there any advantages to upgrading these components?

BTW, I installed a POF roller cam pin for my new MWS upper and BCG and the wear pattern looks much better than my original MWS upper and BCG with factory LMT cam pin.
I would always suggest a Tubbs flat wire spring. Check out the videos about halfway through this link.


They work much better than standard and a no Brainer if not going with something like a JP SCS
 

Sincerd

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I think you’re missing my point. Lmt tubes are straight. Drill the reduced port size in the “top” of the factory tube and run it upside down. Matter of fact, drill the new one straight through so it’ll last twice as long. The port in the tube is going to erode and increase in size resulting in the over gas condition returning.
I did miss that point. How would drilling it through help?

Edit
Oh the new one. So you can turn it upside down. You think these things will erode quickly?
 
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Jsp556

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I did miss that point. How would drilling it through help?
Because then all you’d have to do is turn it over. I think Clint has stated that the gas tubes should last about 5k rounds. That’ll get you through a stainless 6.5 barrel but the chrome lined 308’s are gonna last a lot longer.
 

bgrav321

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I've been reading this thread for a little while. I've wrestled with how to get into the large frame game, and was torn between doing an aero build with some improved components, a Larue UU kit, etc. Then I found a MWS Defender at V1 Tactical, and after reading this thread felt great about buying from them. I ordered one today for 2018 shipped...although it isn't supposed to ship until 3/2021. Should give me time to get accessories I need.

I run a SiCo Omega...do you all think I will need that XH buffer for this?
 

GUNNER10

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I've been reading this thread for a little while. I've wrestled with how to get into the large frame game, and was torn between doing an aero build with some improved components, a Larue UU kit, etc. Then I found a MWS Defender at V1 Tactical, and after reading this thread felt great about buying from them. I ordered one today for 2018 shipped...although it isn't supposed to ship until 3/2021. Should give me time to get accessories I need.

I run a SiCo Omega...do you all think I will need that XH buffer for this?

Omegas appear to have a pretty good reputation for being a high back pressure can so you are going to have to figure out how to over come this on the MWS.

There are a number of ways to achieve this
EZ tune gas tubes,
Adjustible gas keys
XH buffer and spring combo

The best path forward would be to just get a low pressure can but that may end up costing you a grand and 6 months. They are quieter at the shooters ear than a traditional higher pressure can, and you dont have to worry about gas setting backing out or adding reciprocating mass to the system.

The full size high pressure can that I use on my 18 and 20 inch barrels with violent when pared with my 13.5 and 16 inch barrels. My solution was the XH heavy buffer and spring combo as well as a Sandman K. While I would still like to experiment with the stock H3 and Spring combo and sandman K, The 13.5 is very comfortable to shoot. I would say that its almost as nice to shoot as my SR25, and noticeably nicer to shoot than my Scar.

Without a can, That thing barks.