I guess I need more opinions

[Owl21]

Let me start from the top. As a dealer for many AR related parts from a few dozen manufacturers, and having spent the last seven years building and perfecting the AR-15 pattern rifle builds, I have only recently stepped into the fray on 308ARs because of accpeting one on a partial trade.

 

I have found from closely examining the DPMS LR-308 Carbine, reading this forum, and conducting research with several manufacturers of AR paterned 308 parts, that the 308AR is not as simple as the AR-15. So what started off as a rebuild of the DPMS, has turned into a ground up build on the DPMS pattern.

 

I need to build my first one, test, and improve where necessary.

 

Purpose:

• Taining

• Spotter's battle weapon. Engage targets from 50-600 yards in support of sniper, with occasional targets 600-1000 yards.

 

Requirements:

• Weapon system will always operate suppressed

• All ammo will be factory match 168gr

• Weapon system must be carried on patrol, and fired from various positions, including off-hand, sitting/kneeling, and prone.

• Unstable/moving supports in training are common

• Lowest recoil possible while retaining reliable function

 

From my reading, it seems that the DPMS pattern rifles require significant break-in. Can this be remedied, at least somewhat, with a Nickel Boron Bolt Carrier Group?

 

Being always suppressed, what are the best options for mitigating recoil?

 

For the above stated purposes, what would be your stock selection: Carbine or Rifle?

 

Since the weapon system is also carried for patrols (somtimes as much as 12-18 miles in a single training day), weight is an issue. Without sacrificing long range accuracy, what is the best compromise barrel type, length, gas, etc.?

 

At this point, the only parts I have purchased is an Aero Precision stripped upper/lower combo. I am dedicated to freefloating the barrel (likely with a 15" rail), and I have accesses to multiple vendors, and I will be using a Hiperfire 24E trigger group, as well as a bi-pod.

 

Thanks for you thoughts and expertise.

[FaRKle!]

Sounds like you want a 16" or 18" barrel with a mid or lightweight profile. If possible go with a rifle-length gas system (16" w/ rifle gas works just fine on .308s). You may have to have a barrel re-profiled to get what you want (I did with my MWS' barrel).

Since you're running suppressed, an adjustable gas block might be good instead of the heaviest buffer you can find, and it'll be lighter weight.

Definitely go with an adjustable stock system and use AR-10 pattern parts (longer receiver extension, AR-10 spring, and AR-15 adjustable stock sized buffers). Both of my .308 ARs have VLTOR A5 7-position receiver extensions (same size as AR-10 pattern RE), H3 buffers, and Magpul ACS-L stocks.

You're also going to want to reduce the weight in front of the magwell as much as possible for better handling. When I configure my PWS MK216 and LMT MWS to weigh the same, the PWS still noticeably handles better due to less weight out front (the MWS has a thick barrel).

The lightest rails for an LR308 I know of are the Midwest Indsutries SS, Samson Evolution, and Fortis Switch.

Neither of my .308 ARs needed break in for things to run, but the MWS' BCG is hard chromed and the MK216's is polished from the factory (and glides SUPER smoothly through the upper). A coated BCG probably won't encounter any noticeable break-in effects, nor would a quality one I suspect.

Edited July 14, 2014 by FaRKle!

[Robocop1051]

I wouldn't go longer than 16"... honestly, if you're adding a can... build a 12.5" with a permanent can. No SBR stamp needed if the can is permanent, and bbl OAL is over 16". Take a look at the design from McMillan on their "Alias" rifle. There's a company who's entire reputation was built on lightweight accuracy....

Military shoots a 14.5" bbl (in 5.56) out to 600 with open sights... If you can't do that with a short 7.62, your sniper needs a new partner.

[Robocop1051]

Also. Buy a NiB carrier, and then send your upper receiver to WMDGuns to get coated...

I shot my rifle for the first 16 months without oil or cleaning. Never had a single failure.

[Owl21]

I wouldn't go longer than 16"... honestly, if you're adding a can... build a 12.5" with a permanent can. No SBR stamp needed if the can is permanent, and bbl OAL is over 16". Take a look at the design from McMillan on their "Alias" rifle. There's a company who's entire reputation was built on lightweight accuracy....

 

I already have a QD can...it goes on all of my rifles. I am not going to get a special one for this rifle.

[98Z5V]

Military shoots a 14.5" bbl (in 5.56) out to 600 with open sights... If you can't do that with a short 7.62, your sniper needs a new partner.

 

I as just coming in here to add that - good lookin' out, Rob.  <thumbsup>

 

Owl, seems like 600 is the max distance for your objective.  If you were to fab up a shorter version of the M110, that would fill all the roles you've listed. 

 

12~18 mile training movements?  I've never, ever done an infil from that far away from the target.  If you're training with those distances in order to make the shorter distances easier, then I get it.  If you have to make a movement that far just to get to your target, then something is wrong with the planning.  Just the water consumption required for a movement that far - that $hit is heavy, at 8lbs per gallon.  That's not weight that you want to add to your mission.

[Owl21]

I as just coming in here to add that - good lookin' out, Rob.  <thumbsup>

 

Owl, seems like 600 is the max distance for your objective.  If you were to fab up a shorter version of the M110, that would fill all the roles you've listed. 

 

12~18 mile training movements?  I've never, ever done an infil from that far away from the target.  If you're training with those distances in order to make the shorter distances easier, then I get it.  If you have to make a movement that far just to get to your target, then something is wrong with the planning.  Just the water consumption required for a movement that far - that $hit is heavy, at 8lbs per gallon.  That's not weight that you want to add to your mission.

 

Sorry I wasn't more clear. The rifle is multi-purpose. It will be serving in different roles for different purposes. However, if it can accomplish the more difficult task of a spotter's battle rifle, then it will fill the other roles adequately, though likely on the heavy side.

 

A lighter version of the M110 is what I was hoping to accomplish. In my opinion, this would allow the intermediate accuracy desired, while hopefully keeping the platform lighter for (non sniper related) training LRRPs (one of its separate roles where one might travel 12-18 miles in a round trip.)

 

Part of the reason why accuracy is important is because in training it is not uncommon for an evolution to specify that the sniper's weapon suffers a malfunction in the heat of the moment, in which case either the spotter takes all of the targets (out to 1000), or the sniper takes over the spotter's weapon to accomplish the mission, or something similar. In the past, the snipers had been carrying 300 Win Mags, and the spotters were carrying 6.5 Grendel or 6.8 SPC SASS types, among a few others. This was causing a multitude of issues, so it was decided that all will carry .308s to mitigate most of the problems.

 

Beyond all of this, I have a family of NBSs (natural born shooters), myself not being one of them. All of my children are pre-teen, and I want to get the older one's (and my petite wife) on a longer range platform, since they have already proven that consistently hitting a 12" plate at 500 with the .223 is "no big deal" for them - their words, not mine. Because I want to start pushing them out further, I need the recoil to be as light as possible so that they don't quit because of it. I was hoping to use this build for that purpose as well.

[FaRKle!]

I need the recoil to be as light as possible so that they don't quit because of it. I was hoping to use this build for that purpose as well.

Then you'll definitely want a muzzle brake. A muzzle brake plus properly gassed system takes the .308 recoil down a lot (not that a properly gassed .308 has much recoil anyways). An adjustable gas block should help with this a lot too.

[Owl21]

Then you'll definitely want a muzzle brake. A muzzle brake plus properly gassed system takes the .308 recoil down a lot (not that a properly gassed .308 has much recoil anyways). An adjustable gas block should help with this a lot too.

 

YHM makes a QD brake for my suppressor. However, it will still only run with the suppressor mounted.

[washguy]

Owl Apex handguard is super light and easy on the hands......nikon m-308 ...ive got 2 of em and if you are gonna shoot 168 match....its all setup for your holdovers.....we spank steel at 500 without touching the turrets.....:) Wash

[EasyEJL]

the Mako G-Shock stock has some recoil reduction dampers built in

[Owl21]

the Mako G-Shock stock has some recoil reduction dampers built in

 

Thanks, that stock was on my list.

[StainTrain]

Ís this for mil, LE, or tactical rifle competition? Are you building this to eventually market it to mil/LE? I see a whole lotta sniper/spotter references in your requirements and was wondering if this was being built to compete or intervene in a crisis situation.

[Owl21]

Ís this for mil, LE, or tactical rifle competition? Are you building this to eventually market it to mil/LE? I see a whole lotta sniper/spotter references in your requirements and was wondering if this was being built to compete or intervene in a crisis situation.

 

I build for tactical competitions and private group tactical training. I do not market to mil/LE, though they are at most of the competitons, as are many ex-mil guys. I mostly deal with the ex-mil guys who are trying to show up (teach) the "young'uns," and maybe relive some glory days. In fact, a quiet baby boomer that I run into from time-to-time shows up with an old, beat up Mosin Nagant and shoots open sights and consistently finishes in the top half of the pack. The only way anyone seems to beat him is on time, or when the targets are beyond 700ish.

Edited July 16, 2014 by Owl21

[98Z5V]

Part of the reason why accuracy is important is because in training it is not uncommon for an evolution to specify that the sniper's weapon suffers a malfunction in the heat of the moment, in which case either the spotter takes all of the targets (out to 1000), or the sniper takes over the spotter's weapon to accomplish the mission, or something similar. In the past, the snipers had been carrying 300 Win Mags, and the spotters were carrying 6.5 Grendel or 6.8 SPC SASS types, among a few others. This was causing a multitude of issues, so it was decided that all will carry .308s to mitigate most of the problems.

 

What unit or agency was this, that was using 6.5 and 6.8?... 

[Owl21]

What unit or agency was this, that was using 6.5 and 6.8?... 

 

These guys are part of a private training group. Guys with their own stuff that is not associated with whatever they do in their work life. Individually they might be police, mil, ex-mil/police, contractors, or just guys who like to shoot, (though the majority are all ex-something) but together they are just training and testing their own theories. I was one of those who ran a Grendel.