I have been receiving some PMs since I posted pics of my LMT MWS with the Magpul UBR stock installed. For those wanting to possibly change their excellent SOPMOD out for other options here are some things to consider and the details to achieve your desired result. First let me say that I believe the SOPMOD is a great stock and fills the CQB role very well and if I were considering my MWS to be more of a battle rifle I would not make a change. However, I desire to have my 308 act more like an SPR and look forward to some additional barrel options.
Magpul UBR: MIAD Grip w Wedge: Enhanced Trigger Guard
For me the SOPMOD did not work well when shot prone with a rear bag or from the bench. Be aware the 20 round mag is a real pain when shooting from a bench. There are some other great stock choices like the Vltor E-MOD or Magpul ACR that require no modifications or additional items. From the pile of AR15 type rifles lying around here I did have an extra Magpul UBR and PRS that I wanted to try on the LMT.
The journey first began with a call to LMT where I found out that they use a standard AR15 style CAR H3 buffer and as a result they had to make their buffer tube 0.655" longer to accommodate the longer .308 bolt carrier according to their engineer. A majority of other makers like KAC and DPMS use shorter buffers and standard AR CAR buffer tubes. The fact that the tube is longer is apparent in the fact that the stock does not go all the way in against the castle nut like it does on the 5.56 rifles.
TOP: Standard Carbine Buffer Tube. BOTTOM: LMT MWS .308 “EXTENDED” Buffer Tube
LMT MWS .308 SOPMOD Stock, buffer tube, H3 buffer and spring
BOTTOM: AR10 CAR Buffer and modified spring
Knowing this now I contacted Clint Butler at www.heavybuffers.com
Clint makes a HEAVY CAR buffer and modified spring for the AR10 rifle which uses the standard CAR length tube. The combo is not cheap ($111.00) but appears to worth the money as it has helped smooth out the rifle some. Please note that I did not have any function issues at all with the LMT MWS out of the box as it ran fine. AR10 style buffers are available I believe from DPMS and Armalite yet I have told that some of the makers take standard buffers and remove some of the weight and chop them down to shorten them for the AR10. That is something that I didn’t want to chance with this rifle so I went the “Slash” or heavybuffer.com route. A carbine buffer tube was not needed in this case seeing I was installing the Magpul UBR which basically includes the buffer tube in its design. The rifle runs great with the UBR stock and new buffer/spring combo.
Standard H3 carbine buffer vs. Shorter AR10 CAR Heavy Buffer
Heavy AR10 vs. H3
Don’t think the UBR is going to fill the SPR roll that well either for me while it is an improvement over the SOPMOD. Scoped with either a Larue or ADM mount I can’t get a proper cheek weld with the optic so I am going to give my Magpul PRS a try. YUP, just as you guessed more shit to buy!
UBR only offers LOP adjustment
The PRS stock can be purchased for either an AR15 or AR10 type rifle. The difference being in the length of the adjustable comb on the stock. The comb is shorter on the AR10 version so that it doesn’t interfere with the longer charging handle on the .308. Magpul does sale a conversion kit which really isn’t advertised that well and most be ordered direct from the factory to convert the AR15 PRS stock over to the AR10 variant. The PRS AR10/SR25 Retrofit Kit cost $24.95.
Magpul AR10 Retrofit Kit with shorter cheek piece
Detail of shorter comb to allow for longer charging handle
PRS Stock with shorter cheek piece for the longer AR10 charging handle: 7.62 BCM Gunfighter Mod 5
Hold on there is more! Now that we are back to rifle length we need yet another buffer and spring in addition to a standard rifle length buffer tube. Again due to the bolt carrier being longer I needed an AR10 rifle length buffer and spring which is shorter than the one used on the AR15 platform. This time I just bought the Factory rifle size AR10buffer and spring ($42) from heavybuffers.com They do make custom heavier versions as well of this buffer especially for suppressed usage. I can only assume one of them is in my future as well.
Standard AR15 Rifle length buffer vs. shorter AR10 rifle length buffer
Rifle length buffers with springs: TOP: AR15 BOTTOM: AR10
The PRS stock will without doubt fill all my needs and I believe is best suited for this rifle in the Long Range/SPR role.
Hope this info helps those looking at the options.
That’s what I’m talking about!
