LMT MRP Owners

[Razorhunter]

I'm considering an MRP purchase and have a few questions:

1. WHY do the 16" 5.56 MRP's have a midlength gas system, but the 16" 6.8's have a carbine length gas system? I would have loved for them to do the 6.8 in a midlength, JUST LIKE the 5.56, but no, they didn't do it. Anyone have any idea why?

2. Are the gas blocks on these MRP's PINNED? If so, then with 1 OR 2 pins? Taper or straight pins? If not pinned, then what? Setscrews? 1? 2?

3. Is the gas block exposed on a 16" 6.8 CQB MRP? OR is the gas block UNDER the rail? I know the gas block is exposed on a 5.56 16" CQB MRP, so I would ASSUME that with the 6.8 being a shorter length gas system, that the gas block would be UNDER the rail on a 16" CQB. Is this correct?

4. Anyone know why they didn't offer the M4 profile on the MRP bbls? Would there by any reason for this, or what? I have always loved the look of the M4 profile bbl.

Very important Question here:

5. In regard to the new gas piston MRP coming out, I had read a while back, that the NEW GAS PISTON MRP's would have ONE difference when compared to an older DI MRP. The difference mentioned was something along the lines of a special "coating" on the inside of the upper or something like that? Not sure if it is something for the BCG to "glide" better, or what?
Can anyone tell me more about this? I know I read it either here or on the "other" forum. I would just like to know exactly what differences will exist between a NEW Gas Piston MRP and an older DI MPR upper? (aside from the gas piston system itself of course) I could have sworn someone mentioned a special lubricating "coating" of some type, but I just cannot recall. ???
Thanks for any help.

[khc3]

1. Don't know. I think I have read that 6.8's gas port pressures are lower, so the benefits of mid-length gas system aren't present with that caliber.

Anyway, LMT could have made tha barrels either way, so I'm guessing the shorter gas length works fine.

2. Pinned, with one pin. Don't know if it's straight or tapered.

3. Gas block on 16" 6.8 barrel is covered by the CQB rail.

4. You can't mount a M203 on a MRP using the standard M4 barrel mount, so the M4 barrel cut would have been pointless.

5. Sorry, don't know.

[Razorhunter]

Awesome khc3,
I appreciate you clearing a few things up for me.
Now, if I can get someone to answer questions 2 and 5, I'll be good to go.

I'd also be interested in hearing more opinions from others on why LMT might have chose to go with the CARBINE length gas system on the 6.8 MRP's, as opposed to going with the Midlength system as the 5.56 MRP's have?
Thanks again khc3.

[khc3]

5. I will say that the pics I've seen of the piston system show the bolt carrier with some kind of coating, almost looks gold like TiN. That may be what they're referring to, in addition to the normal dry lube they apply to their uppers.

But again, I don't know the details.

[Razorhunter]

Yeah, I know their Piston Carriers will be different, that's for sure.
However, I was reading somewhere a while back, that the INTERIOR of the UPPER receiver on the new Gas Piston MRP's, would have some type of special "coating" or something?
Again, not sure, but I'm sure someone knows.

[Boomer10]

Not trying to sound like an ass or anything, but have you contacted LMT with your questions?

I'm not sure about the coating that you're asking about, but when I talked to the LMT guys at the SHOT Show they said that the TiN coating would be an option, but not standard.

[Spooky130]

Here's a picture of the pinned gas block on my 6.8 barrel:
http://i126.photobucket.com/albums/p89/Spooky130_photos/IMG_1140.jpg

I took the calipers to one of the barrels and the pin holes measured .110" on both sides so I think they are straight pins.

Here are a couple other pics after not cleaning for a couple hundred rounds and then going to a Pat Rogers carbine class - an that BCG is a chrome Young version.

http://i126.photobucket.com/albums/p89/Spooky130_photos/IMG_1141.jpg

http://i126.photobucket.com/albums/p89/Spooky130_photos/IMG_1142.jpg

http://i126.photobucket.com/albums/p89/Spooky130_photos/IMG_1146.jpg

Proof that lube can go a long way...

Spooky

[Razorhunter]

Well Boomer, I'm not saying you're being an "ass" or anything, but obviously you sound like one, or you wouldn't have needed the disclaimer.
By the way, what's the point of your question? Obviously anyone with the intelligence to ask a technical question on this forum, also has the common sense to call up LMT if they have the chance.
Which brings me to my next point that you obviously haven't considered. NO, I haven't called LMT. I have a hard enough time getting by the bank, Post Office, or making any phone calls during the work day. If it were a dire emergency, sure I could possibly find a way to make time to call them.
However, it's not a dire emergency, and asking technical questions is EXACTLY what this forum is for. Have you ever noticed the title of this forum?
If no one ever asked questions like this, the forum would be DEAD, and would never have any traffic, or daily posts.
IF your question had even the slightest bit of merit, then it should be asked to someone who gets on this forum and starts yet another thread along the lines of "Who makes the best BCG" or "WHO makes the BEST AR???" or "How to clean an AR???" or "Thoughts on Bushmaster"???? or "WHY Is Colt so good??"" etc, etc.
Ok, enough. You get the point. I don't mean to sound as coming off as pissed to you, but you knew that question would come across as an attempt to make me feel my post has no merit. Not saying you MEANT to come across this way, but that's how it sounded, and you knew it before you posted anyway. No offense. Just responding to your question.:)

Sorry for the interruption folks.
Hey spooky thanks bro! Yeah, I suppose it is a straight pin. I'm just glad it's pinned, and I won't have to deal with pinning yet another gas block or FSB myself.
I know the Tin coating Boomer mentions is frequently used on drills, for improving wear characteristics, and durability, but I don't know if LMT is offering (or will be offering it) on their BCG's or on the interiors of the MRP gas piston uppers???
Not sure. I wonder where this was first learned? I will try some Googling, and reading back over the original LMT Gas Piston article in the 2007 Book of the AR15.
Thanks so much guys. I appreciate it.

[Shihan]

Paul just a FYI LMT will have the piston in the CQB and not the MRP and are not planning on doing it.:(

[nickdrak]

Paul,

I have not heard anything about a coating specific to the piston MRP uppers, but there is a metal sleeve inserted in the newer MRP's gas tube hole in the receiver. Mine does not have it, as mine is about 4 years old, but all of the recently manufactured MRP's have the metal insert from what I have been told (by Gene of LMT), and I was also told that I could send my MRP in to be retrofitted with the metal sleeve.

All of the most recently manufactured MRP's I have seen are coming with an additional integral QD sling swivel point on the very front of the side rails.

ETA: I once ran my MRP uncleaned for 2,000rds without a cleaning, but with plenty of lube without any malfunctions.

[Spooky130]

I would imagine that the piston operating rod would be too long in a rifle-length MRP but just right for the CQB-length MRP.

I think that rifle has close to 2,000 rounds through it. I know it had 1,400 through it in three days!

Spooky

[Razorhunter]

Paul just a FYI LMT will have the piston in the CQB and not the MRP and are not planning on doing it.:(



SHIHAN,
I think what you are trying to say is that the piston system will ONLY work in a CQB MRP, and NOT in a Rifle MRP.
They are ALL MRP's (which means "Monolithic Rail Platform").
ONE is a "CQB" or "carbine length" MRP, and the OTHER is a "Rifle" Length MRP.

I am fully aware that the piston system will not fit under the MRP rail, and therefore it will only work with the carbine length or "CQB" MRP upper.

As far as I can best tell, I think Boomer up above is closer to what I'm talking about. He referred to a TiN (or Titanium Nitride I think) coating.
However, Boomer has not mentioned if LMT is offering the TiN coating on the BCG itself, OR on the interior of the Upper Receiver???
What say Boomer?
Thanks guys.

[Shihan]

I was being specific with regards to the CQB and MRP names that LMT uses on the 2 different length systems. I was unsure if you knew LMT wasnt making one in the future that would work with the longer MRP.

[Razorhunter]

Ok, I gotcha,
Sounds like we are on the same page. CQB MRP = CARBINE LENGTH Monolithic Rail Platform and Rifle MRP = Rifle length Monolithic Rail Platform.
Gas piston system will ONLY fit under the CQB length rail.
Thanks.

[Shihan]

Ok, I gotcha,
Sounds like we are on the same page. CQB MRP = CARBINE LENGTH Monolithic Rail Platform and Rifle MRP = Rifle length Monolithic Rail Platform.
Gas piston system will ONLY fit under the CQB length rail.
Thanks.

Part of the confusion is that they are both MRP's but now LMT to differentiate between the two calls the longer one the MRP and the shorter one the CQB.

[Cold Zero]

Does anyone have the LMT Gas piston? Or know when they will be available?

[Boomer10]

Paul, I'm not 100% sure about wether or not LMT plans on putting that coating anywhere else besides the BCG or not, but (and this is just my opinion on this) based off of the conversation I had with one of the reps at SHOT I don't think it will be on anything other than a BCG. I can't remember all of the details of that conversation but I'm pretty sure it won't be on the inside of the receiver.

However, that is not to say that there will/will not be a different coating that I'm not aware of in the receiver. I do know that when I looked at it that it appeared normal to me (other than the BCG).

[Razorhunter]

Thanks Boomer, I gotcha.

Cold,
I have seen on another forum that LMT is promising some dealers a "June" delivery.
He is the only guy I have seen mention a specific MONTH. Everyone else, including Grant on this forum is saying "15 weeks from SHOT?" or something like that.
I know some dealers are saying "15 weeks from whenever you place your order", as they keep hearing 15 weeks, regardless of when they call LMT. Go figure.
I DO think we'll see it before the Colt piston gun, but that's not saying too much...

[AnchorArmament]

Does anyone have the LMT Gas piston? Or know when they will be available?

Ours should arrive mid June. I'm keeping my fingers crossed. I get an update every couple weeks and the shipping date hasn't changed.

Lead time is 16 to 20 weeks for 16" uppers / carbines from when the order was placed.

[Cold Zero]

Paul & A.A.:

Thanks for your input. I am surprised that no one has managed to get their hands on one, post pictures and a review on the internet, like with so many other new products.:eek:

[Razorhunter]

Have you seen the review that was done in the Book of the AR15?
Yes, I realize that a magazine author is not the same as a regular individual, and there can be some "bias", but it had complete pics and everything.
Someone did upload the entire article online, either here or on ARFCOM.
The pics have been out for a long time. Even LMT's catalog has pics. The pics in Book of the AR15 are much better, and show more detail.
Most people have clearly seen the piston, and what it looks like.