Specs for my Longbow

DMack Uncategorized 8 Comments

First of all… why do I call it my “Longbow”? Well… traditionally, the Longbow added range to the Archers who used them, and were force multipliers on the battlefield of yore. It took considerable time to hone an Archer’s skill with the Longbow, in regards to accuracy, and rate of fire. Once proficient with the Longbow, they were able to deliver precision arrow placement, much further than the other Archers.

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Running a “Gas Gun” efficiently at distance, is a skill that needs to be honed. I started calling this rifle my “Longbow” based on this fact. It delivers a higher rate of fire than a standard bolt rifle, with surgical accuracy. I thought the moniker was fitting.

Ok, thoughts behind the rifle.

As a Law Enforcement Trainer, I think about what they need in the scope of their day to day duties. As a Law Enforcement Sniper, I started thinking about what I would want in a duty rifle, and started looking into how to make that happen.

Bolt rifles are very accurate, but also suffer in multiple round engagements over the AR platform. However, AR’s traditionally were not very accurate in comparison to the bolt rifle. So, I set out for realistic accuracy parameters. I wanted SUB MOA accuracy out to 200 to 250 yards. Why? Well, for a Law Enforcement Sniper, this is paramount. During a barricade incident, or a Hostage incident, it is very likely that a cranial vault shot is the shot of choice. Being able to make that shot at a reasonable distance is the measuring stick. So, being able to repeatedly hit the T Zone at distances out to 200 yards was realistic enough to see if I could achieve.

In a Hostage type scenario… as a marksman, I would always attempt to close the distance as much as I could, to help mitigate liability. Can you hit a head sized target at 800 yards? Yes… people do it all the time. But, as a Law Enforcement Officer, would I be able to justify that shot on the stand? Hmmmm….

Ok, second accuracy parameter… MOM (Minute of Man) out to 600 yards. Why? Well… imagine an open air / non barricade / non hostage shot… bad guy is in the open, backstop is clear, bad guy has a rifle, and is openly a lethal target. It is absolutely feasible to be able to hit center mass of the torso out to 600 yards… so, that was my accuracy “box” I needed the project to fit in. Sounds easy, but… you’d be surprised.

I had a MEGA Monolithic MA-TEN upper  and lower that I wanted to use as a donor platform to build from. I liked the monolithic upper, because of the way most rails / tubes locked down…  on a number of AR-10 style rifles I had tested, I was able to induce vertical stringing at distance, by inducing barrel torque, by loading the bipods like I would a bolt rifle. Yes, the tubes were free floating… but, they attached at the barrel nut, and I was able to get enough torque in from the bipods to cause some issues. With the MONOLITHIC upper, all the torque is taken by the take down pins. Very nice thought… works in practice too.

MEGAMA-TENDonor

I wanted to be able to remove my magazines whilst still prone, behind glass. Most AR-10 style rifles are battle rifles, designed to be fired standing up. When prone, on the AR-10 style rifle, using bipods, almost every rifle out there, you have to tip the muzzle to remove the magazine. I really like the 20 round 7.62 PMAGS and that was my measuring stick. A Law Enforcement Sniper also has to consider load out in regards to ammo. I wanted to be able to switch from open air rounds, to barrier rounds or subsonic rounds without coming off glass. This necessitated a side charging handle. I wanted the charging handle on the left side, since the VAST majority of shooters are right handed, and would be running the rifle from the right shoulder.

This meant cutting up the MEGA Monolithic Upper, and I was so committed to this project, that I went forward with it. Little did I know, that there would be a patent issue looming, and the MONOLITHIC uppers were to be no longer had.

So, on the mill it went. I cut down the mag well on the left side, to effect mag changes whilst prone. A slot was milled in the left side of the upper receiver, to effect a side charging handle. Then the BCG was modified / drilled / threaded to accept the charging handle…

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Barrel selection was next. I went through a few barrels, and ended up with the JP Supermatch barrel, and it is amazing. I also knew I wanted this rifle to be suppressed, for shooting from confined space. All in all, this rifle is absolutely amazing. It runs so well, and shoots so accurately, it captures everyone that shoots it. I’m working on re-producing something very similar to this, to offer to Law Enforcement. In the end… here are the parts.

Upper / Lower: Mega Arms Monolithic MA-TEN (No Longer Available… however their new stuff is awesome)

LPK: Standard DPMS style LPK

Saftey Selector: Short Throw levers from Battle Arms Development. I use the LONG lever on the right side of the lower, and the short lever on the left side. I really like this set up on a precision rifle, because I do not hold the grip like a normal rifle. I roll my thumb over the backstrap, and rest it on the safety lever on the right side of the rifle. My trigger finger is indexed on the trigger, and my lower three fingers are indexed along the front edge of the grip. No cardiac impulse is induced, and with the Battle Arms Development levers, I can actuate the safety with ease.

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Trigger: I started out with the Geissle SD-E, which I loved… but the hammer pin kept walking out. I used KNS pins to fix this issue. Now, I am running the CMC Tactical Trigger, Flat Bow and love it. It’s the trigger that I have in all of my rifles  at this point.

Grip: MAGPUL MIAD… Large backstrap. It fits my hands perfectly. I use the MIAD on all of my rifles.

Stock: MAGPUL Precision Rifle Stock (PRS). This is for comb adjustment and length of pull adjustment.

Buffer: Slash’s heavy buffer – AR-10 style, rifle length (I feel this is a very key component in the build)

Buffer Spring: Also from Slash’s site… recommended for use with his buffer

Bolt Carrier: LMT (DPMS pattern) bolt carrier / firing pin / spring / cam pin / firing pin retaining pin – carrier is MICROSLICK coated

Bolt: JP enhanced bolt – headspaced to the barrel

Barrel: JP Rifles “Supermatch” Cryo Barrel – 18.5” long, 1:10 twist, mid-length gas system chambered in .308 WIN (Match Grade Chamber). I am now running a barrel from Craddock Precision, 18″ 1:10 twist, Mid Length Gas System, .308 WIN Match chamber… DPMS style barrel extension.

Gas Block: Syrac Ordnance / JP Minimized gas block with lockable adjustment. I chose this one, so I could tune my rifle to the rounds used, with the suppressor on it. This, is one of the contributing factors for accuracy in my opinion. I have adopted this gas block on all of my precision rifle builds. It is infinitely adjustable from full open to full closed in 1/4 turn increments. This allows for a custom tuned gas system based on the ammo / suppressor used. ABSOLUTELY essential in dialing in your gas system, and these gas blocks (pricey) are worth every penny.

Gas tube: Standard, mid length gas tube… DPMS style, not Armalite style.

Suppressor: Right now, I have the new suppressor from LeHigh Defense on the rifle. This is a 30 cal Titanium can, with muzzle adapter. However, what LIVES on this rifle is my Brevis full size 7.62 suppressor from Delta P Design.

Muzzle Device: If not suppressed, I run the Precision Rifle Compensator (PRC) from Primary Weapons Systems (PWS).

Bipod: Harris “S” notched, 6-9” with the DLOC / SARG knob from  Alamo Four Star

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Optic: Bushnell Elite 3.5-21 with G2DMR reticle

Optic Mount: DLOC 34mm from Alamo Four Star

Level: US Optics Pic Mount Level

Finish: Cerakote – Flat Dark Earth / Black

Sling: VCAS from Blue Force Gear

Comments 8

  1. I love the write up and detail you give, and thanks for taking the time to post this up. I’m sure you’ve gotten lots of emails asking for this exact spec sheet. I’ve been looking into the LVOA REPR and was hoping you could give some thoughts on where the rifles differ and pros and cons on each. Thanks again. God bless

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        Author

        Rob, I have had mixed results with the LWRC REPR platform. Also, of note, I have only had limited experience with it. They are accurate, but they are a short stroke piston design. The piston itself causes debate among AR Precision Shooters. I chose to build this rifle from very well thought out, and personally selected components, that anyone can replicate. Well, almost anyone. The key to how this rifle shoots so well, is the sum of ALL of it’s parts. Most effectively, the ability to very finely tune the gas system. Most production rifles have set gas port sizes, or limited adjustment capability. This is because of mass produced / production rifles, to the untrained masses. If there is an adjustment on it, people will monkey with it, and when the rifle stops running, blame goes back to the manufacturer.

        I tune my gas to the round / suppressor… once tuned, if I switch rounds, or take the suppressor off, this changes the gas pulse. I don’t mind tuning my rifle, and knowing it’s status. That’s why if I build one for a customer, I take in account what ammo they are using, and then I teach them the tuning process. Most AR .308 / 7.62 rifles are notoriously over gassed to begin with.

        In the end, if you are wanting to go with the LWRCi REPR, then commit to it and learn to shoot it effectively. I have a PWS MK214 that I use in a DMR style role, and it is very reliable and accurate out to 600 yards easily. Accuracy opens up a bit, due to velocity from the 14.5″ barrel at 800 yards, but still is very acceptable. The long stroke piston system of the PWS rifles, would be my go to choice in piston technology, just based on my own use.

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    Author

    I guess I round about answered your question Sir, so here goes another stab at it. This is a Direct Impingement Gas System, the LWRCi REPR is a Short Stroke Piston Gas System. Both accomplish the same thing, only by different schools of thought. Is one better than the other? No. Apples to Bananas. Most modern rifles are more accurate than the normal shooter. I would decide realistically what you are going to do with the rifle, how often you will shoot it, at what REALISTIC distances you will shoot… and then hone in my decision. Suppressed? Not Suppressed? High volume of fire in dirty conditions? Or typical range duty, or precision carbine matches? The piston does have merit, but there is zero wrong with the DI system either.

    1. Awesome. Thanks for the reply! I was also looking at the PWS so thanks for including that. You’re an great guy to follow on instagram, keep posting badass, honest reviews!

  3. Just came back from long-range precision marksmanship class at FTW in Texas, using the Ruger SR762 from 100-1000 yards. Gun performed admirably on the last day of class “quiz,” 10 12-inch plates from 363-750 yards, multiple shooting positions, cross-canyon, up and down angles, etc. I want to take the gun to the next level. I’m used to the SSA trigger (use them on my 3-Gun rifles), so I was going that route. PRS stock? What buffer system? Muzzle brake?

    Thank you in advance!

    Michael B

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      Author

      Michael,

      For a PRECISION rifle, there is nothing wrong with the SSA. However, the SSA-E may be a bit more suited for your intended purpose. Another trigger that I would recommend is the SD-E (with it’s flat bow). This allows a more consistent pull and consistent finger placement. Just beware that the two stage trigger takes a bit of practice in a competitive precision environment. I have switched to the CMC 3.5 pound flat bow trigger in all of my rifles, due to the fact that it works in both a “stand up” gun, and a “lay down” gun. Plus, it has an index ramp at the base of the trigger bow that allows me to position my finger in the exact same place, every time. Repeatability is paramount in the precision game.

      I really like the PRS (Precision Rifle Stock) for the Gasser. It allows perfect comb height adjustment, as well as length of pull adjustment. As for buffer, I use the Heavy Rifle Buffer / Spring combo from Slash’s Heavy Buffers. Here is a link to it…

      http://heavybuffers.com/ar10rifle.html

      Another thing I use is the Syrac Ordnance adjustable gas block. This allows me to fine tune my gas system, and get the rifle shooting as soft as possible without being over gassed. Here is a link for it as well:

      http://www.syracordnance.com/products/gen-ii-750-adjustable-low-pro-solid-gas-block-stainless-steel-finish

      Glad to hear you are shooting some good stages. When set up correctly, the “Gas Gun” is just as competitive, in some ways, more so than a bolt gun. Will they ever replace the bolt gun? No. But, it is a HUGE force multiplier when employed correctly.

      If you have any questions, don’t hesitate to ask.

      v/r

      DMack

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