LMT MARS-H and Large Frame Uppers

[wichitaguns]

Hey guys,
Has anyone done the crazy thing of trimming a non lmt upper (think aero precision or some other builder grade upper) to fit a lmt mars-h lower?
I want an lmt mws rifle, but can probabaly get the lmt mars-h in short order.

 

[JS8588]

Just buy a V7 Harbinger stripped upper or a Stag 10 stripped upper. Either will function with the MARS-H lower. For that matter, so will Mega uppers.

 

[wichitaguns]

Thanks for the information..that is exactly what I was.looking for

 

[Merle]

And it will look awesome!

 

[wichitaguns]

And it will look awesome!

Which combination?
Or is it any combination?

 

[Merle]

Any upper other than a KAC or LMT upper on a LMT MARS lower will look like a trailer house room addition.

 

[wichitaguns]

Any upper other than a KAC or LMT upper on a LMT MARS lower will look like a trailer house room addition.

Oh I agree. I was trying to get it all in a hurry. But after doing the math, I end up losing money and time vs just getting the lmtmws upper and being done with it.

 

[WillHugh]

Someone really needs to make a SR25 pattern upper receiver (which is what fits the LMT). I have a mars-h lower I want to build out with a urx rail and dimpled barrel, but can't find anything short of an actual sr25 upper that matches well. Heck, at this point I'd pay $500 for a stripped knights receiver, but they're impossible to come by.

Centurion came out with a receiver set that was supposed to match the kac cuts, but the reports I've read make it sound like it's slightly off - they're supposed to be reworking, so stay tuned I guess .

- Will

 

[wichitaguns]

Am I the only nerd, totally enamored with the lmt barrel attachment system?
I.know its overkill and you loose about to pic handguard, but the elegant simplicity and ruggedness of it is great.
I remember that being the thing that finally made me pony up the cash for the mrp.

 

[WillHugh]

Am I the only nerd, totally enamored with the lmt barrel attachment system?
I.know its overkill and you loose about to pic handguard, but the elegant simplicity and ruggedness of it is great.
I remember that being the thing that finally made me pony up the cash for the mrp.

Not at all - I think it's definitely a superior system. The monolithic rail is going to be the most rigid option for mounting bipods, lasers, etc, and the ability to quick change barrels is really cool. I think my interest in being able to build an upper has more to do with wanting a kac than it does with thinking the lmt is inferior in any way.

The downsides I see to the lmt upper are its weight, the short rail, and being stuck with lmt barrels (not that they're bad, just somewhat limiting).

- Will

 

[t9regg]

Older thread, but I’m a new LMT convert and wanted to share a lesson learned. Just found an over run of the 308 piston barrel for LMTs Estonian Defense Force contract. Hadn’t convinced myself I needed an Ar-10 platform, but this was too rare to pass up. I had a stag stripped lower (agree with previous trailer edition comments) that I was going to put a new mrp on for a quick solution. Long story short…they are not compatible. Got lucky and found a MARS lower for $500, jumped on it and am now just waiting for all the parts to show up to finish the build. I’ll update with a pic once it’s complete.

 

[Huskydriver]

Older thread, but I’m a new LMT convert and wanted to share a lesson learned. Just found an over run of the 308 piston barrel for LMTs Estonian Defense Force contract. Hadn’t convinced myself I needed an Ar-10 platform, but this was too rare to pass up. I had a stag stripped lower (agree with previous trailer edition comments) that I was going to put a new mrp on for a quick solution. Long story short…they are not compatible. Got lucky and found a MARS lower for $500, jumped on it and am now just waiting for all the parts to show up to finish the build. I’ll update with a pic once it’s complete.

Interesting cuz here is a stag ar10 upper on a mws mars h lower...

 

[t9regg]

The upper has a lip, that I assume fits a recess on the MARS lower. The rear takedown pin impacts the upper receiver and there is visible overlap between the upper and lower take down holes.

 

[t9regg]

Worth pointing out…this wasn’t an issue with the MRP-L on my STAG 5.56 lower.

 

[TheOE800]

The upper has a lip, that I assume fits a recess on the MARS lower. The rear takedown pin impacts the upper receiver and there is visible overlap between the upper and lower take down holes.

Those are file to fit…there is no recess on MARS L lowers.

 

[t9regg]

Those are file to fit…there is no recess on MARS L lowers.

Awesome! Thanks for sharing!

 

[wichitaguns]

Awesome. But inquisitive minds want to know..did you say 308 PISTON barrel? Any pics..I didnt think they made a piston 308 barrel..and does that also mean they make a ar10 sized bolt carrier which can work with the piston?
And where did u find this unicorn?

 

[TheOE800]

Awesome. But inquisitive minds want to know..did you say 308 PISTON barrel? Any pics..I didnt think they made a piston 308 barrel..and does that also mean they make a ar10 sized bolt carrier which can work with the piston?
And where did u find this unicorn?

Estonia contract barrel.

 

[t9regg]

Awesome. But inquisitive minds want to know..did you say 308 PISTON barrel? Any pics..I didnt think they made a piston 308 barrel..and does that also mean they make a ar10 sized bolt carrier which can work with the piston?
And where did u find this unicorn?

Estonia contract barrel.

Right on, it is an overrun for the EDF contract. I’ll post a pic of the final build when my MARS lower gets in. Pre Covid, I believe LMT intended to release a civilian version in 2021. Seems unlikely based on current demands of their mil contracts.

 

[t9regg]

I’ll post this on the 308 builds thread with more details, but here it is! Didn’t need to file the “speed bumps,” nice tight lock up, too. What you’d expect from LMT!

 

[longshot2000]

Someone really needs to make a SR25 pattern upper receiver (which is what fits the LMT). I have a mars-h lower I want to build out with a urx rail and dimpled barrel, but can't find anything short of an actual sr25 upper that matches well. Heck, at this point I'd pay $500 for a stripped knights receiver, but they're impossible to come by.

Centurion came out with a receiver set that was supposed to match the kac cuts, but the reports I've read make it sound like it's slightly off - they're supposed to be reworking, so stay tuned I guess .

- Will

Yeah, Centurion is reselling someone else's upper. We got excited when they told us they had a Mk11 upper. The forge markings were the same as others we had in the shop. I think we have tried every combination of upper and lower in .308 to recreate the Mk11 look and feel, and the closest anyone has gotten is the older Gen 1 Genesis from circa 2018. The Gen 2 Genesis were not fit for purpose. LaRue fits the SR25 patter pretty well, but their upper - rail combo puts it at a disadvantage, like the MWS unified upper.

 

[Huskydriver]

Stag upper finally built out...

Hopefully get some loads through it in the next two weeks.