Small Unit Tactics contact patriot-dawn Patriot Rising

Building a 5.56 DMR

Home Forums The Lounge Building a 5.56 DMR

This topic contains 10 replies, has 10 voices, and was last updated by Profile photo of Free Chicken Dinner RRS 1 year, 10 months ago.

Viewing 11 posts - 1 through 11 (of 11 total)
  • Author
  • #43366
    Profile photo of Chris

    Looking for a little input from the gun guru guys here on the Forum…
    I’ve got an AR15 Lower I’m looking to build-out. I’m thinking about building it to function as a DMR that can reach out a little further than my ‘standard’ AR’s with 16″ barrels.
    My plan is to use an Magpul stock with adjustable pull and comb; drop in adjustable trigger (Timmeny); variable power scope; 24″ heavy barrel; free float handguard with bipod….
    Sound about right or am I way off?
    Thanks, cw

    Now that I'm over 50 I realize that my People Skills are is my tolerance of Idiots that needs work.

    Profile photo of

    Geissele SSA-E Trigger. It is designed and built for that application.

    List Price: $240.00
    Generally Available price: $185.ish
    Real value: Priceless
    My opinion….avoid adjustable triggers. If your going to build a build a heavy barreled rifle with a 20″ plus barrel……consider building an AR-10

    Profile photo of Brian from Georgia
    Brian from Georgia

    Are you going to patrol with it? If so, you are going to hate carrying around a 24″ heavy barrel. The heavy barrels also tend to be “accuracy” barrels with tighter chambers and no chrome lining. This makes them less dependable for combat field conditions.

    How far is your longest shot? If it’s 600 yards or less, a chrome lined A2 barrel from a reputable manufacturer will do the job in a lighter and more dependable package.

    My answer for a DMR is a 20″ A4 with FN A2 profile chrome lined barrel and A2 buttstock, free float handguard, bipod, Geissele SSA-E trigger and 3X9X40 scope. The rifle will shoot sub-1.5 MOA and is still combat reliable. It’s performed well at MVT a couple times.

    3-4 Aug 2013 CRCD, 2-6 Aug 2014 CRCD/Patrol, 30 Sep 2016 Run n Gun, 1-2 Oct 2016 FoF, 3-4 March 2018 DCH alumni
    Team Coyote

    Profile photo of Lloyd

    Double ditto on the Geissele SSA-E trigger! I have broken several “match grade” triggers over the years, but have put 30k+ rounds through several rifles with Geisseles and never had a problem.

    Also, good advice on barrels above. I’m no “sniper”, but I can make hits just fine on 12×16 inch steel at 600yds with a 14.5″ chrome-lined lightweight barrel if I do my part and the wind isn’t too squirrely. 16″, 18″, or 20″ is all you need. I think optic choice, ammo choice (for wind-bucking), and skill are MUCH more important than barrel length/weight.

    If you really think you want sub-moa, a Compass Lake or White Oak SPR or Recce contour stainless barrel will be your best bang for the buck. No need for a super heavy, or super long barrel with 5.56. Again, optic, ammo, and skill are what is going to make the hits.


    We are all victims of our perspective.

    Profile photo of Jamison

    Get a good quality 16″ barrel and free float it, Geissele SSA-E and run 77smk pills through it. A high quality bomb proof scope will work awesome for that application. 9x max power is good. Maybe if you really want to have fun with it, run an 18″ SPR barrel, but I wouldn’t worry about going much over 20″. Get a high quality collapsible stock.

    You’ll like this setup a lot better than a heavy 24″ barreled anything.

    Admit nothing. Deny everything. Make counter-accusations.

    Nulla fatere. Nega omnia. Accusatis calumniatorem. Demanda probationem.

    Profile photo of Chris

    Yes, going to patrol with it…
    Thinking effective range as 600 yards +/-…
    Thanks guys! This is exactly the kind of input I was looking for ?!

    Now that I'm over 50 I realize that my People Skills are is my tolerance of Idiots that needs work.

    Profile photo of Frostysliverback

    16″ or 18″ barrel, HBAR or SPR profile, free float handguard, and drop the $ on the SSA-E.

    Profile photo of BrigandActual

    Monty, of Centurian Arms, once made the argument that the ideal combination of barrel lengths for the 5.56 is 12″, 16″, and 20″. The 24″ is honestly just too long for all but he most specialized benchresr purposes. The 5.56 was originally optimized for a 20″ barrel, and that’s what I would suggest you scale down to.

    What kind of accuracy requirement do you need? You could further shave weight by switching from a heavy stainless barrel to something like a Criterion hybrid, which is more of a mid weight but still returns +/- 1 MOA.

    I’m also a fan of Geisstle triggers, and have the SSA-E and SD-E. both of those are more than suited for your task.

    "Man is still the first weapon of war" - Field Marshal Montgomery

    Matt B - VA

    Profile photo of Jake

    If your budget allows, check out High Caliber Sales. They make premium uppers suited for your purpose. I’ve not personally purchased an upper from them. I have not ventured far into the SPR/DMR market but when I commit, I will purchase my URG from HCS. Always go with Geiselle triggers. They are the best. No need for a 24″ barrel. 16″-20″ barrel will suit your needs. Kreiger also makes excellent barrels can provide a barrel to fit your needs.

    My mom said I could be anything I wanted to be when I grew up. So I chose to be a man.

    Profile photo of Pinky

    I think there are diminishing returns beyond an 18″ barrel. Are you interested in a non 5.56 round? If so, check out 6.5 Grendel. Especially now with 24 cent per round ammo. I have taken my 18″ barrels grendel now to 500Y with boring repeatability. I have also taken my Larue 18″ to the same with 77gr 5.56. Just some info to share FWIW. Bottom line is I don’t think you need a 24″ barrel to,do,what you want

    "No free man shall ever be debarred the use of arms."
    -- Thomas Jefferson

    Profile photo of Free Chicken Dinner

    I have a Rock River Arms 20″ inch heavy SS barrel with Wylde chamber, free floated handguard and Harris bipod. So far so good but it is not my first choice of go to war rifles since its matched with a lower that is not ideally specced to a rifle length upper. The Priv P M-193 is reliably 1 1/2 to 2″.

    I’m using a Leupold 3-9 with the well thought out etched for M-193 BDC that is remarkably spot on in adjustments.

    Thinking of trying one of the heavier bullets like 77 OTM for accuracy and then having Leupold custom etch another turret for what seems a reasonable price.

    Tactical training for Liberty, Fraternity, Excellence

Viewing 11 posts - 1 through 11 (of 11 total)

You must be logged in to reply to this topic.