Suppressors LMT MWS Suppressed Buffer and Spring Options

[Glassaholic]

LMT uses a proprietary method of putting on their gas blocks using a hydraulic press, also their gas port is at 45 making it impossible to find an aftermarket adjustable gas block that will work with a stock LMT MWS barrel That being said, I just got my tax stamp and my TBAC 30BA suppressor in a record 6 months from submittal! Now it's time to take this beauty out and see how quiet she is.

It is because of this very issue that I am looking at spring/buffer alternatives with my LMT LM8 (slick rail) MWS. The adj gas block is really not an option for those of us wanting to use factory barrels (alternatively you can get MWS conversions done with the AR-10 barrel of your liking at LMT BARREL CONVERSIONS). I have heard some MWS owners with suppressors feel the stock setup with the H3 buffer works just fine for suppressed and unsuppressed; however, it seems that most (non MWS owners) feel they get a better recoil impulse by using the adj gas block and/or the heavier buffer.

I have a Magpul PRS stock on mine and have decided to get the JP Enterprises Silent Captured Recoil Buffer Spring (JPSCS-AR10) for the AR-10 which, according to JP, comes with their 10-110 spring - their heaviest spring for this system. JP offers a spring kit that comes with a 10-100, 10-105 and 10-110 springs so your only options are going lighter which with the suppressor we don't want to do so there is no need for me to purchase the spring kit.

I know a lot of shooters use the Heavy buffers setup, but I'm hoping the JPSCS will do the same but also offer the "silent" capture part which it was designed for. What I do not know is how does the JP system with a 10-110 compare to something like the AR10R-XH Buffer + Spring Heavy Buffers | Products | .308 Rifle

Has anyone used both, curious what your experience was, thank you.

PS - Will update soon with my experience using the JPSCS

 

[itieknots7]

Interested in your results and others input.

I have an LM8 on order that should be here next week. I'll be shooting it 90% of the time with a SOCOM762-rc and was probably going to go the heavy buffer route through Slash's website.

Op, what buffer tube did your rifle come with? Carbine or rifle length?

 

[bnanaphone]

I have one of the earliest MWS rifles that has roughly 1700 rounds through it, (700 by me and 1K by the previous owner). I recently received my Specwar 762 silencer and run it with their brake mount. I am running the stock RE with ACS stock and have only replaced my buffer spring with an Orange SprinCo spring, and I'm still using the H3 buffer. I have never tried the JP buffer.

I have only run 100 suppressed rounds through it in this configuration. Over the weekend I had two double-feeds with FGMM 168 and one stovepipe with Hirtenberger. This was odd because I have had no malfunctions with the rifle without the silencer attached. I am guessing the additional pressure on an already overgassed gun could be the culprit. I should also point out that the gun has not been cleaned in 200 rounds, with half of those being suppressed. I did make sure to lube up the BCG well with frog lube before shooting too.

As far as shooting the gun in this configuration, it was great. By that I mean the recoil is not as sharp as it normally was with the stock spring, and shooting it unsuppressed felt like a slightly more potent 5.56 gun with zero muzzle rise. The orange spring and 3-chamber brake significantly mitigated recoil and rise.

I have not tried swapping the buffer spring back and forth for testing or feel, I just run it with the orange spring and rock on. I hope this gives you a little more information.

 

[Glassaholic]

Op, what buffer tube did your rifle come with? Carbine or rifle length?

My rifle came with the carbine buffer tube and LMT's awesome SOPMOD adjustable stock; however, I wanted more LOP and cheek riser adj. with a March F 3-24x42 with a GG&G one piece mount so that's why I bought the PRS. I really like the Luth-AR design but his is really lightweight and I thought the PRS would balance out the front heavy situation with the suppressor mounted.

I am actually selling the carbine buffer tube/spring/H3 and SOPMOD combo if you are interested Well, I was going to re-purpose the tube and stock for another build, but let me know as it's just been sitting around since I got my PRS.

 

[Glassaholic]

Wow, the guys at JP really impress me, good group to work with! I have been in contact with them about the JPSCS-10 for my LMT suppressed and this was his response:

If you’re going to run both suppressed and unsuppressed without an adjustable gas system then I would also recommend using a heavier buffer. We have Tungsten weights available that replace the stainless steel weights that come on the JPSCS-10. The extra mass will help deal with the varying pressures of shooting both suppressed and unsuppressed or just the extra gas of shooting suppressed in a rifle gassed for unsuppressed. If you want to go that way you can order it right from me, they aren’t available online yet.

Dave Cammack
Engineering, Technical Support & Quality Control
JP Enterprises, Inc
651-426-9196 voice

I just ordered the two tungsten weights from Dave, had a great conversation with him about the LMT's and how you can't use an adjustable gas block and it really sounds like the JPSCS-10 will be the ideal setup. I wish I hadn't already bought the JPSCS-10 as he was willing to sell me one that already had the tungsten weights installed from the factory, but he walked me through how to update mine once I get the weights, it's a little complex but should be something I can do on my own.

He also mentioned that you want to make sure that there is always tension on the SCS to the bolt, you don't want any slop in there and some rifle tubes are too long so he said to get a 7/8" neoprene washer from the hardware store (I had always heard to use a quarter) and the neoprene acts as an additional buffer while providing the needed tension against the BCG.

Great info that I thought I'd share here with y'all. I put Dave's information above in case anyone else would like to go this route, definitely give him a call if you would like these tungsten weights (Note: the tungsten weights are only for the JPSCS-10, but he did mention they will be making some for the 5.56 JPSCS-15 as well)

 

[LVdubbin]

My LMT is a severely overgassed pig! Especially when suppressed. I run a Slash XH heavy buffer, but I think it needs even more weight...

 

[Glassaholic]

LVdubbin, looks like you have a very short barrel or is that the standard 16" and just the perspective and lens used. Nice spikes on your atlas, better than a bayonet

 

[Glassaholic]

With my PRS I have a rifle length buffer tube with JP polished rifle spring (for AR-10) and an H3 buffer that shot unsuppressed just fine. After attaching my Thunderbeast (TBAC) 30BA I could not get the next round to chamber as I ran into a number of issues with the over-pressured gas system. Last week I received both my new Tungsten weights from JP and my new JPSCS-10 from MidwayUSA. Here are my findings -

The tungsten weights felt significantly heavier than the steel weights that came with my JPSCS-10 so I took both sets and weighed them on my postal scale (not super accurate but good enough to the ounce). Results:
Standard Steel Weights = 1.2 oz
Tungsten Heavy Weights = 2.6oz

After putting everything together I took my LMT out to the range with some handloaded 165gr Hornady SST's I had laying around. First thing I noticed was that the charge cycle was much smoother and easier than with the spring/buffer combo. The next thing I noticed was that the LMT was able to cycle the next round without any issues, and then the next round and the next round and never did I encounter a cycling issue with the 30 rounds I shot that day.

Being new to suppressors, one thing I did notice was that shooting suppressed with a gas system means a much dirtier BCG and casings, thankfully LMT makes their MWS bolt with NiB and the unknown finish on the carrier was pretty easy to cleanup as well, but there was quite a bit of carbon build up on the back side of the bolt and inside the carrier where it's hard to get, but since this is the first time I took apart the BCG to clean it and several hundred rounds have already passed through :snicker: I don't think I can blame the suppressor for all of this

Undoubtedly a big reason for how much dirtier this runs with a suppressor is due to the fact that I do not have an adjustable gas block, but that is just something us LMT shooters are going to have to live with since changing the gas block is not an option for us at this time, it sure would be nice if LMT offered an adjustable or switchblock type of design like they do for their 5.56 piston barrels to cut down on the amount of gas when using a suppressor.

Those issues aside, the JPSCS-10 gets my thumbs up vote as it solved my cycling issue while shooting suppressed, made charging the system easier and shooting quieter.