Experience with LMT Piston MRP

[77Bronc]

My entire collection of rifles are LMT's, that is what I collect...I came real close to getting a piston MRP today, but backed off, to do more thinking...

Asking the 'Hide members for some real feedback on this design and LMT pistons...I have read a lot opinions that the original DI is the way it is meant to be and should stay that way. To date my LMT'S have not failed, but something is telling me to get a piston rifle.

Any opinions would be greatly appreciated.

Thanks,

77

 

[jakhamr81]

Re: Experience with LMT Piston MRP

I had one for about six months. I had all kinds of malfunctions; failure to cycles, and the BCG just running sluggish. I realized that the cause of all my frustration was a severe case of carrier tilt. The bolt carrier was being pushed back at a downward angle and grinding away at the receiver extension.

When I contacted LMT with the problem, they looked at the pictures, claimed to have never heard of carrier tilt, and accused me of causing the problem because of my "radical" modifications (new grip and a Magpul Bad Lever).

I'm sure that some of their guns run fine, but I will never buy another LMT product.

 

[Foomanshoot]

Re: Experience with LMT Piston MRP

I have had a similar experience with the LMT upper and replaced it with an adams arm complete upper. The tollerences seem to be tighter on the Adams Arms and some adition steps have been taken to prevent carrier tilt.

 

[hk dave]

Re: Experience with LMT Piston MRP

The piston for an AR15 is marketing hoopla. It's unnecessary. The DI gun does just fine and has proven itself over many years and battle zones.

Just buy 2 DIs for the price of the piston.

Unless you are an operator, what possible reason could a person have for needing a gun that shoots straight out of water and can run a thousand rounds without cleaning?

Piston rifles also have a different recoil impulse, if you shoot a lot of DI guns, you might notice it.

BTW nice choice with the LMTs... i love LMT myself.

 

[77Bronc]

Re: Experience with LMT Piston MRP

Whooa boy, glad I asked, like I said in the original post, the DI LMT's have done me well, very well, the DI MRP is outstanding...glad I put the wallet away and drove home.

Below is my range cart (I made) with the rack of LMT's, with one Remington tactical SG:

77

 

[Wolf22]

Re: Experience with LMT Piston MRP

Ran my LMT MRP suppressed and the ejector vacated (broke that is) after 6 rounds. LMT took care of things fairly quickly, been fine ever since.

.01c

 

[TheTrauma]

Re: Experience with LMT Piston MRP

My LMT piston is up to 2000-3000 rounds. Not one problem, not even carrier tilt.

 

[saryan]

Re: Experience with LMT Piston MRP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Wolf22</div><div class="ubbcode-body">Ran my LMT MRP suppressed and the ejector vacated (broke that is) after 6 rounds. LMT took care of things fairly quickly, been fine ever since.

.01c </div></div>

One of my students had this problem 3 weeks ago. LMT fixed it. I have personally seen DI guns go until the safety lever could not be switched one handed because of the carbon build up. We had to strip the whole lower and scrape it out. Gun worked fine with lube, NSW guy just kept lubing it up. It was a MK18 with the NT4 suppressor. Needless to say, I'm a DI fan.

 

[jake6547]

Re: Experience with LMT Piston MRP

I would choose the piston for a suppressed rifle, way less blow back and great accuracy!! I do agree the piston guns are a little more picky with ammo though.

 

[jakhamr81]

Re: Experience with LMT Piston MRP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: jake6547</div><div class="ubbcode-body">I would choose the piston for a suppressed rifle, way less blow back and great accuracy!! I do agree the piston guns are a little more picky with ammo though.</div></div>

A suppressed gun will get dirty regardless of if it is a piston or DI; the round is extracting while the gun is still under pressure (this is why the cases are black). All the crap is being thrown back down the barrel, not through the gas tube that causes a suppressed gun to run dirtier.

If you are looking to go suppressed then think about an adjustable gas block. This way you can also control the cyclic rate, which would be more crucial if you are also firing full auto.

 

[jake6547]

Re: Experience with LMT Piston MRP

The lmt pistons have an adjustable gas block, for normal and suppressed fire. The gas port is less then half the size on suppressed to reduce cycle rate.

 

[branson1369]

Re: Experience with LMT Piston MRP

IMHO the piston is fixing a problem that does not exist. I shoot a couple thousands of rounds from my guns per month and clean mine every couple of range trips. For an AR 15 CQB rifle 500 to 1000 rds with lube sprayed on the bolt every 300 or so rounds should be fine with no malfunctions for a class of several range events. Then apply 30 minutes of effort cleaning and PM'ing the rifle. Does not seem out of line to me.

You save the money on the piston for better kit/ammo and you do not get the out of balance forward end of the rifle and change in impulse of the gun.

But I guess I am old school I like things that work and stick to them

 

[tactic-als]

Re: Experience with LMT Piston MRP

Jackhamr81, will you tell us when this happened? I seem to recall seeing these pics quite a while ago. Is it beyond reason that LMT has done a redesign to resolve carrier tilt? Has anyone heard of such an issue with LWRC rifles?

I was just getting ready to start such a thread. I'm interested in the LMT MRP piston upper. My M&P15-T does work fine but I just bought a LWRC REPR, I'm now a piston fanboy. I performed an initial lube, ran the gun for about 100 or so rounds, broke it down and was amazed that the bolt looked like brand new. With about 200 or so round thru the M&P, I have to spend 30 minutes scrubbing the carbon off the bolt. I was going to get a M6A2 or M6A3 upper to replace the M&P upper. However, I started leaning toward the LMT MRP piston upper due to it being several hundred dollars less and experimenting with the different options this design allows.

I know everyone says get a DI gun and spend the extra money on ammo or training. Well, IF price is no object (and the piston gun had no issues) would you still be running the tried and true DI gun and spending 30 minutes every couple hundred rounds to clean the bolt or finding some way to better utilize that time?

 

[saryan]

Re: Experience with LMT Piston MRP

I clean my bcg every 400-600 rounds. It will run well over 2k IF I keep it lubed. Pistons are neat but not required. I'm pretty in tune with my rifle since I use it every day and can tell when it needs more lube.....



<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tactic-als</div><div class="ubbcode-body">Jackhamr81, will you tell us when this happened? I seem to recall seeing these pics quite a while ago. Is it beyond reason that LMT has done a redesign to resolve carrier tilt? Has anyone heard of such an issue with LWRC rifles?

I was just getting ready to start such a thread. I'm interested in the LMT MRP piston upper. My M&P15-T does work fine but I just bought a LWRC REPR, I'm now a piston fanboy. I performed an initial lube, ran the gun for about 100 or so rounds, broke it down and was amazed that the bolt looked like brand new. With about 200 or so round thru the M&P, I have to spend 30 minutes scrubbing the carbon off the bolt. I was going to get a M6A2 or M6A3 upper to replace the M&P upper. However, I started leaning toward the LMT MRP piston upper due to it being several hundred dollars less and experimenting with the different options this design allows.

I know everyone says get a DI gun and spend the extra money on ammo or training. Well, IF price is no object (and the piston gun had no issues) would you still be running the tried and true DI gun and spending 30 minutes every couple hundred rounds to clean the bolt or finding some way to better utilize that time? </div></div>

 

[Skyjunky]

Re: Experience with LMT Piston MRP

If you have the money to spend go ahead, I love mine, goes forever without cleaning, and when you do there's not much to clean. Barrel doesn't get that hot either.

 

[saryan]

Re: Experience with LMT Piston MRP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: Skyjunky</div><div class="ubbcode-body">If you have the money to spend go ahead, I love mine, goes forever without cleaning, and when you do there's not much to clean. Barrel doesn't get that hot either. </div></div>

Barrel gets hot like always. The piston up front gets ridiculous hot. The BOLT doesn't get as hot like a DI does though. I am assuming thats what you meant.

 

[77Bronc]

Re: Experience with LMT Piston MRP

Thanks to all that replied, the feedback was great...I am going to think about it. I have a lot of gun irons in the fire now, really can wait on another project.

The MRP is a great line, when I picked up that piston MRP a few days ago, it felt great...

Thanks,

77

 

[jakhamr81]

Re: Experience with LMT Piston MRP

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: tactic-als</div><div class="ubbcode-body">Jackhamr81, will you tell us when this happened? I seem to recall seeing these pics quite a while ago. Is it beyond reason that LMT has done a redesign to resolve carrier tilt? Has anyone heard of such an issue with LWRC rifles?

I was just getting ready to start such a thread. I'm interested in the LMT MRP piston upper. My M&P15-T does work fine but I just bought a LWRC REPR, I'm now a piston fanboy. I performed an initial lube, ran the gun for about 100 or so rounds, broke it down and was amazed that the bolt looked like brand new. With about 200 or so round thru the M&P, I have to spend 30 minutes scrubbing the carbon off the bolt. I was going to get a M6A2 or M6A3 upper to replace the M&P upper. However, I started leaning toward the LMT MRP piston upper due to it being several hundred dollars less and experimenting with the different options this design allows.

I know everyone says get a DI gun and spend the extra money on ammo or training. Well, IF price is no object (and the piston gun had no issues) would you still be running the tried and true DI gun and spending 30 minutes every couple hundred rounds to clean the bolt or finding some way to better utilize that time?</div></div>

I believe that I first posted those picks sometime around the end of last year. I bought that gun early 2010.

As far as cleaning goes, I run my DI guns suppressed. I spray a coat of Rem oil on the BCG and bolt prior to going to the range. When I notice a build up of soot (usually after 500 rounds or more), I spray the BCG down with brake cleaner, knock the soot off with an AP brush, wipe down with a rag, reassemble, and re-lube. This whole process maybe takes me ten minutes.

I spend much more time cleaning my bore than the BCG. Being a former Marine, I used to have the mentality that I had to scrub every bit of carbon off of my rifles after every session at the range. I have found that this is very unnecessary and bad for the rifle. ARs are meant to be run dirty, just keep them lightly lubed and they will run fine for 1,000+ rounds without cleaning.