Long question about ARs

[Winnerkd]

Hello M4Carbine.net!
I have a question for you; it seems buying a rifle has turned into a Pandora's Box of unanswered questions. My options currently are:

LMT .308 Chrome Line 16''

LMT 5.56/.223 MRP w/ 18'' SS barrel

Noveske 18'' SPR w/ VIS

Here my issues with each, The LMT .308 has only a 16'' barrel, I'm wondering if this carbine gas system is a good combination with .308. My issue is 500-600y accuracy since the 16'' is, as I'm told a bit ''short. Here is the ''issue'' I'm talking about
''an AR in 308 with the shorter 16 inch barrel...and the consequent shorter gas system...suffers from the same deficiencies as an AR in 5.56 / .223 with the shorter carbine length gas system...it will be less reliable and more ammunition sensitive...driven by greater peak port pressures resulting is greater expansion chamber pressures...it will have the same issues with hard extraction as the .224 caliber version...and will operate less smoothly with more perceived recoil...to name a few...

...aside from this...the 16 inch barrel will reduce the velocity potential of the 308 cartridge...reducing its effective range...for example...this reduction of velocity versus the 20 inch or longer barrel will increase the height of your MRT...decrease your point blank range and increase the duration of exposure to unfriendly environmental variables...such as any wind present...by increasing your time to target...resulting in greater drift...especially at longer ranges...''

LMT 5.56
My Issue with the LMT MRP is this, how will it fit on my KAC lower. Since I can change the barrel on my own the barrel longevity on SS won't be a problem, and it's a rifle length MRP! It's a very sexy set up I think. Aside from that, I'm told the MRP is a great platform! I'm told LMT is as quality as one can get, much like KAC and Noveske. Though I suppose I can order a LMT lower for this sexy MRP. And I'm told the rifle length gas system is the ideal gas system?

Noveske 5.56
I cannot change the barrel. Once it's done, it's done, though I suppose I can buy a new upper.
Are any of these concerns legitimate or am I being really REALLY picky? I shoot through 5-7k rounds a ''season'' so I do a lot of shooting.

Let me thank you all for sharing your knowledge with me!

[ucrt]

Here's a little of what I (think) know.

FWIW - I have an old Remington 788 in 308. It came with an 18" barrel and I have consistently made 300 yard shots with factory 308 Win. ammo. I wouldn't feel handicapped out to 400 but beyond that?? But you want shorter...?? Personally, I think an "AR" 308 would be nothing more than a plinker. I've never read any where that they can gold up like a quality AR. There's even a thread here (I think) where some asks "what's a good semi-auto 308" and the only recommended gun was a M1A1.

The LMT MRP's use a proprietary barrel. A mil-spec barrel will not fit. A special "wrench" is needed to remove the barrel.

Noveske (Vltor) VIS uses standard mil-spec barrels and they are changeable with the "wrench". I'd bet Noveske would give you a wrench with the VIS.

The bottoms of the MRP and the VIS remove to access the barrel nuts.

[Belmont31R]

1. The LMT MWS with a 16" CL barrel is a battle rifle. Not a precision rifle. If you go back through history, and our current wars most contact distances are well within the range of a 16" 7.62 weapon. Its not really meant to be shooting past "combat" distances, and thus the 16" CL barrel is just fine. Its also going to last longer than an SS barrel. The idea of a battle rifle is so you can still use it clearing houses and the like, and still be able to make an affective 500 yard shot if you need to. Longer guns like the M110 fill the semi auto precision role, and is not really meant to be clearing houses with or firefights, etc.


2. The MRP should mate up to a KAC lower just fine.

Rifle length gas systems make for a smooth shooting gun but you can only go so short of a barrel. I personally like mid lengths, and intermediate length like the KAC SR15 14.5 or a 16" barrel.

[Winnerkd]

I had no idea the VIS was a able for the user to change the barrel if need be! That makes me choice so much easier!

Out to 500m is about as far as I would go with the LMT 308!

I think my choice is made on the Noveske!

[Iraqgunz]

Wrong answer. As has been talked about here many times barrel length does not equate to accuracy. It relates directly to muzzle velocity. If I (or many other shooters) can hit a target at 500+ yards with a 5.56 so can someone with a .308.

As mentioned in a previous thread the instructor who taught my SPR Course used his short barreled PoF rifle to hit targets out to at least 800 yds.


I had no idea the VIS was a able for the user to change the barrel if need be! That makes me choice so much easier!

Out to 500m is about as far as I would go with the LMT 308!I think my choice is made on the Noveske!

[Sanpete]

Here's a little of what I (think) know.

FWIW - I have an old Remington 788 in 308. It came with an 18" barrel and I have consistently made 300 yard shots with factory 308 Win. ammo. I wouldn't feel handicapped out to 400 but beyond that?? But you want shorter...?? Personally, I think an "AR" 308 would be nothing more than a plinker. I've never read any where that they can gold up like a quality AR. There's even a thread here (I think) where some asks "what's a good semi-auto 308" and the only recommended gun was a M1A1.

The LMT MRP's use a proprietary barrel. A mil-spec barrel will not fit. A special "wrench" is needed to remove the barrel.

Noveske (Vltor) VIS uses standard mil-spec barrels and they are changeable with the "wrench". I'd bet Noveske would give you a wrench with the VIS.

The bottoms of the MRP and the VIS remove to access the barrel nuts.

A bit of not-quite-accurate info here.
LMT MRP system uses a different type of barrel attachment, but does not require a proprietary or special wrench. It's a torque wrench, that's it. You just have to torque the two torx fasteners to 140 inch pounds, and the rifle comes with everything you need including the wrench. You could use a standard torque wrench if you want.

The Vltor VIS uses a completely different tool that is supplied with the upper receiver.

The LMT bottom rail is not removed to access the barrel nut. The Vltor VIS is (really it's just a small cover but the whole bottom rail does remove too).

[Winnerkd]

Wrong answer. As has been talked about here many times barrel length does not equate to accuracy. It relates directly to muzzle velocity. If I (or many other shooters) can hit a target at 500+ yards with a 5.56 so can someone with a .308.

As mentioned in a previous thread the instructor who taught my SPR Course used his short barreled PoF rifle to hit targets out to at least 800 yds.

This is good food for thought! Thank you, and everyone who has replied. I have an extra ACOG that might find it's home on the LMT if I decide on it.

[Todd.K]

Two things.

I don't know if the rail on the 16" MRP will cover the gas tube if you install the 20" barrel.

The VIS is not quick change or anything like that. It has a barrel nut and a special wrench. It will require some tools and an upper block but anyone who can change a barrel on a regular AR can do so on a VIS with the wrench.

[Winnerkd]

I'm still very much up in the air,

I already have a KAC SR-15 IWS, I'm wondering if adding the Noveske to my collection at this time would be the best option. The LMT seems very appealing! I plan of coming back to Noveske for my SBR build this Fall.

The SPR requires expensive ammo, that I can't always get from Wal-Mart. I could also use the ACOG 3.5x on the LMT where as I would need a new optic to take advantage of the SPR.