I am considering buying a used LMT MRP, and until recently mentioned in another thread here, was not aware of different generations of this AR. Can someone explain to me the differences from one generation to the next, and how I can tell which generation this specific rifle might be?
Thanks,
Pete
Pete, you’re probably best calling LMT for details.
The first generation MRP came in the AR-15 platform. You could get barrels from LMT in 5.56, 6.8, .204, and optionally purchase barrels from Spikes Tactical in .22 and 9mm. There were two options of upper receivers—CQB which has rail similar to a mid-length gas system and Rifle, which has enough rail to mount optics out and push a bipod out further as well.
You barrel choices could some in piston variety, and/or stainless, in SBR lengths, and you didn’t have to buy a new receiver to make a different gun. If you wanted to switch your 12.5" 6.8 CQB to SDMR role with a 18" bbl then you could do so quickly and with less expense than buliding another upper receiver. And should you need to go back to CQB role you could. Your zero apparently would not change as well should you have appropriate optic mounts.
The new MWS is also a monolithic rail platform, however it is based on the AR-10 platform in .308 and has been fielded by the British MOD for it troops. There are fewer barrel choices currently however that will change. LMT is shipping these guns with a 16" barrel however a 5R stainless bbl is coming. I’d love to see them offer a 243 or 6.5 Creedmore barrel setup, but then on the original MRP I’d love to see a 6.5 Grendel or 7.62x39 barrel as well. Heck, a .357sig option to match my Glock 23 w/Lone Wolf would be awesome…
LMT sells magazines in 6.8 and 5.56 although PMags work in the MRP and the .308 Pmags work in the MWS.
I know there is “talk” on the 'net of those systems possibly having bent rails and being impossible to fix. I have yet to actually hear someone say “my MRP is BENT.” Nowhere. Not the first example. Maybe with the Brits shooting because they ARE in a combat zone with them and had to use one as a baseball bat against a jihadist or something but I really doubt it.
I think you can find that you’ll have a lifetime purchase with the MRP as LMT does make rifles for the USGovt that are being used to defend our Constitution against all enemies foreign and domestic and I believe that you’ll be very pleased with it. Hope this helps.
MWS—
MRP—
That isn’t what he is asking.
He is asking about the different generations of 5.56 MRP. Things like with or without female sling sockets, etc.
Generation I: First models released back in the Fall of 2004, featured no QD sockets and used two silver washers underneath the two bolts and called for 90lbs of torque when torquing them in.
Generation II: All models have QD sockets forward of the receiver on both left and right side. The earlier Gen IIs used the silver washers and 90 lbs of torque, however sometime the switch was made during the Gen II period in which the chassis switched from using two silver washers to a single figure 8 washer and recalibrated the specs for torque which called for 140lbs of torque to be used in conjunct w. new figure 8 washers.
Generation III: Every single model has 4 QD sockets both front and aft, left and right…as well as all having figure 8 washers and calling for 140lbs of torque.
That is the only differences from the earliest model to today’s most current.
Figure 8 washer vs. single silver washers
And that is in inch lbs NOT foot lbs.
Priceless…you sure are my proof reader…following the posts and cleaning em up, thanks:p
Thanks to everyone for the information and clarification. Much appreciated!
-Pete
No. There is a HUGE difference between inch and foot lbs. The torque wrench that came with my MWS is almost exactly like the torque wrench that I already had which is in foot lbs except for the little markings on the dial. Its important to distinguish between the two.
I’ve made that mistake before. Someone usually catches it.
Well hopefully i at least got all the generational and timeline info right as Im sure somebody else knows that information and would have chimed in with it very shortly:)
I inquired about the torque values and was told that 140 inch/lbs is the value for both the silver washers and the figure 8 washer. The reason for the figure 8 was for logistical reasons only. It can stay in place when the front-most bolt is removed during barrel changes, eliminating the chance of losing the one silver washer belonging to the removed bolt. The generational comments regarding the QD sockets is correct.
Hope this helps.
ETA, the man (who will remain unnamed so he doesn’t get in trouble) said that the torque wrench included with the MRP uppers and MRP rifles is pure junk. Better than nothing, but users are best served with a good Snap On or other more reputable. I just purchased a Stanley Proto for $157, which is too much to buy one for each of my 6 MRP’s. Maybe I’ll try calibrating the cheapy Chinese ones from LMT and use them in a pinch.
I got mine in January of this year…It was ordered Nov 09 and I was told it would be a 4 month backlog.
Mine is the 16" CQB MRP Piston, and it is consistent with the above descriptions of the most recent iteration. It is a great weapon that I use for work but it seems slightly on the heavy side. Never had a malfunction after multiple classes and range days.
So according to your info no MRPs ever required only 90lbs vs. 140lbs 
This may be alittle off the subject but It’s LMT were speaking about (right) I will try an explane myself. I plan to purchase the MRP soon but the barrels that are offered are not to my liking. I have read that there is an adapter to except the barrel of choice that become part of the LMT receiver and wil allow mating the barrel of choice giving the user a varity in barrel choice. Can someone add to this?
Thanks
There is a company offering a modification service to standard barrels for use in an MRP. LMT actually sold their proprietary barrel extensions years ago but quickly abandoned that practice. So, today you basically have three choices:
Spooky
Trident, I cannot say they never required 90 inch/lbs as you have written. Maybe they did at one point. I am just saying LMT’s current spec is 140 inch/lbs for both types of washers, that’s all.
That makes sense, the first spec was 90 in/lbs…and they only had the old washers. They changed the spec to 140 because I guess barrels were coming loose sometimes? So the current spec is 140 no matter what washers you have.
I’d like to get a couple extra bolts to have on hand just in case, kinda a silly order on their own though w/ shipping. Don’t really need anything else from LMT…
I have discussed this a cpl. times with a pal @ LMT and the info I posted above is from him directly.
The actual chassis minus the additional QD sockets added has been totally untouched since the production MRP was released. If the washers were not supposed to be torqued to diff. values than LMT for no apparent design reason decided to add 50 lbs/in more torque on the chassis without changing any of the specs…unlikely they would just change torque values if they did not alter either the chassis or the actual washers.
Back from my MRP days I remember there being a metal gastube hole insert/liner that was added to the newer generation MRP chassis to work with the piston assemblies.
Basically, if you plan to run a piston barrel assembly in your MRP, make sure you have a newer generation with the lined gastube hole. If I remember correctly, the gastube liner came on-board at the same time the 4 QD sockets were added.