308 Win AR build - thoughts

JayJay Senior MemberPosts: 2,891 Senior Member
According to my long term budget, I will have my target budget for the 308 AR build next month. So, I’m shopping for parts and formulating a plan. Thoughts are always welcome. While I’ve built many AR15s, this will be the first “full grown” AR.  The targeted budget for this build, including optic and mount, is $1500. I already have an Aero Precision lower receiver, so all I need is the rest of the gun....

First thing I’m undecided on is barrel length. 16”, 18”, 20”? My plan for this is to use it for some hunting. Deer, elk, hogs and predators. But it will probably be mainly used at the range. Not too heavy and bulky would be nice so it’s not a pain to carry. And range will be from right in front of me to 300 yards for practical use. Maybe an occasional stretch out to 600. With those parameters, I’m thinking 16”, but I’m open to suggestions. 

As im doing some shopping, I ran across a website called Ground Zero Precision. Never used them before. But they have some build kits that appeal to me. Prices don’t seem to out of line. And I like the fact that many of their kits use Aero Precision upper receivers. That takes a lot of the guess work out of the whole DPMS/Armalite, tall/short pattern thing. Aero is a DPMS tall pattern.  They also use a certain longer pivot pin, which comes in the kit, as well as threaded bolt catch pin. I don’t like the hand guards and stocks they offer in some kits, but they sell a kit with everything but the stock and handguard. It also comes with an adjustable gas block, which is a must for me on this build. That’s the one I’m considering. 

https://www.groundzeroprecision.com/collections/ar-10-lr-308-build-it-yourself-project-kits/products/ar-10-308-kit-aero-precision-ballistic-advantage-slr-rifleworks-16

For stock and handguard, I’m considering these two. Light and compact enough, but useable for different tasks. At least, it seems that way to me. 

https://www.groundzeroprecision.com/collections/ar-10-stock/products/luth-ar-mba-4-adjustable-carbine-ar-stock-cheek-rest-black

https://www.groundzeroprecision.com/collections/ar-10-lr-308-free-float-hand-guards-rails/products/leapers-utg-pro-13-super-slim-free-float-lr-308-rail

For the optic, I’m thinking 1-6 or 1-8 scope on a cantilever mount. Looked at a Vortex that’s seems decent, with BDC reticle. Always open to more options there as well. 

Upgrades planned for for after the initial build will be a better trigger and possibly a muzzle brake. 
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Replies

  • MichakavMichakav Senior Member Posts: 2,098 Senior Member
    edited June 9 #2
    Personally, I would go at least 18", if not 20" for the .308. That is purely personal preference. I like that little extra velocity for a "do-all" AR.
  • JayJay Senior Member Posts: 2,891 Senior Member
    18” is a definite possibility. I’d have to shop around some more or hope that GZP gets more stuff in stock. Right now, most of their 18” kits that I’d be interested in are out of stock. 20” is a possibility as well, although I already have a 22” bolt gun. Seemed like something a bit more compact would be cool. But I’ll admit, I haven’t checked theoretical ballistics differences out to 600 yards between the 3 lengths. 
  • MichakavMichakav Senior Member Posts: 2,098 Senior Member
    edited June 9 #4
    Jay said:
    18” is a definite possibility. I’d have to shop around some more or hope that GZP gets more stuff in stock. Right now, most of their 18” kits that I’d be interested in are out of stock. 20” is a possibility as well, although I already have a 22” bolt gun. Seemed like something a bit more compact would be cool. But I’ll admit, I haven’t checked theoretical ballistics differences out to 600 yards between the 3 lengths. 
    Since you have said that, I would go 16" because you have the bolt. The difference at that yardage, and even a little further, will be negligible. The 16 will be lighter and easier to pack around and does not give much up.
  • knitepoetknitepoet Senior Member Posts: 17,075 Senior Member
    Just for giggles, using a "max" load of Varget and the ubiquitous 168 SMK in QuickLoad, going from a 16 to 18" gained ~75fps and 18 to 20" gained about the same.

    So you're looking at 150 fps difference, at least with that one load.

    Out to 300 I really don't see that making much of a difference, and out to 500, shouldn't be more than a few inches
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • ZeeZee Senior Member Posts: 19,185 Senior Member
    I fought against the LR-308 platform for years. I’ve seen them break left and right and have yet to have a model survive the class I teach.  None of the high end Gucci rifles could handle the volume of fire and environmental conditions without breaking. 

    So, it was with great trepidation that I finally built my own last year. But, it wasn’t until I think I figured out the problem that I built my own. 

    Over gassed. Most all broke in one way shape or form because there was too much gas shooting ammo designed for bolt guns. 

    Ammo makers capitalized on this by coming out with lower pressured ammo designed for the LR-308 guns. And basically castrating the cartridge. 

    I said piss on the lower pressure rounds and built a gun that could handle the higher pressure stuff. 

    3 Words:

    Adjustable Gas Block
    "To Hell with efficiency, it's performance we want!" - Elmer Keith
  • ZeeZee Senior Member Posts: 19,185 Senior Member
    And here she is. 


    "To Hell with efficiency, it's performance we want!" - Elmer Keith
  • ZeeZee Senior Member Posts: 19,185 Senior Member
    So, my thoughts/suggestions.

    16” Barrel - I’ve handled the longer .308 gas guns and they just aren’t fun. At that point, give me a bolt gun. I’ve shot to 600 yards with both my 16” gas and bolt gun without issue. 

    15.5” Free Float Forend - it looks better and feels better. Plus, it gets the bipod out close to the Muzzle and adds stability when shooting with a rear bag. 

    Fixed Stock- Honestly, I’m gravitating towards a fixed stock for any and all ARs. A fixed stock is better from the bench and with magnified optics in general. I have an adjustable stock on my Colt 901 and hate it compared to the fixed stock on my built gun. 

    Geissele Trigger - Damn good triggers. 

    Magpul K2 Grips - More vertical and better for bench/prone shooting in my opinion. 

    Adjustable Gas Block - I wouldn’t build an LR-308 without one. 
    "To Hell with efficiency, it's performance we want!" - Elmer Keith
  • JayJay Senior Member Posts: 2,891 Senior Member
    Thanks guys. 

    Ah yes. There’s the rifle that nudged me in the direction I’m at least looking toward. I’ve also known of over gas issues with the 308 platform ARs and read your build thread on that gun. So, adjustable gas bock it will be. Then I can tune the gas block to best match whatever load I come up with for it. 
  • JayJay Senior Member Posts: 2,891 Senior Member
    Zee said:
    So, my thoughts/suggestions.

    16” Barrel - I’ve handled the longer .308 gas guns and they just aren’t fun. At that point, give me a bolt gun. I’ve shot to 600 yards with both my 16” gas and bolt gun without issue. 

    15.5” Free Float Forend - it looks better and feels better. Plus, it gets the bipod out close to the Muzzle and adds stability when shooting with a rear bag. 

    Fixed Stock- Honestly, I’m gravitating towards a fixed stock for any and all ARs. A fixed stock is better from the bench and with magnified optics in general. I have an adjustable stock on my Colt 901 and hate it compared to the fixed stock on my built gun. 

    Geissele Trigger - Damn good triggers. 

    Magpul K2 Grips - More vertical and better for bench/prone shooting in my opinion. 

    Adjustable Gas Block - I wouldn’t build an LR-308 without one. 
    Definitely appreciate you’re input. 

    Good to know on the 16”. I was thinking that as well. The confirmation is appreciated. 

    I’ll search for a longer handguard. The UTG I was looking at is 13.5. I don’t plan to run a bipod, but could be a consideration later. Shooting sticks/trigger sticks/bog gear is what I envision when not on the bench. 

    Damn. It might take some time to pull me toward fixed stocks on a gas gun...

    Buddy at work said he has a brand new Geissele. Might just see what I can get it for. I run RRA NM 2 stages in all my ARs. Not the best trigger, but great trigger shot for the money. Maybe this one needs something a bit nicer. 

    Definitley noted kn the grip. I was thinking more vertice grip. That along with the design of the stock in the link I posted seemed to have potential for bench and field used. Stock has a flat bottom to ride a bag, adjustable cheek piece and looks to have a nice little hand hold spot on the front for the left hand. Just a theory at this point. 
  • ZeeZee Senior Member Posts: 19,185 Senior Member
    That butt stock you linked looks like a bunch of smoke and mirrors to me. 

    And a longer forend works from a tripod/bog pod as well. That’s what I’ve been using to shoot most of my pigs with lately. My built LR-308 and a Bog-Pod from a kneeling position in the ag fields. 
    "To Hell with efficiency, it's performance we want!" - Elmer Keith
  • JayJay Senior Member Posts: 2,891 Senior Member
    Noted. I’ll look around and see what else I can find. That’s not exactly a cheap stock, either. Maybe find something better and not quite as expensive. 
  • JayJay Senior Member Posts: 2,891 Senior Member
    knitepoet said:
    Just for giggles, using a "max" load of Varget and the ubiquitous 168 SMK in QuickLoad, going from a 16 to 18" gained ~75fps and 18 to 20" gained about the same.

    So you're looking at 150 fps difference, at least with that one load.

    Out to 300 I really don't see that making much of a difference, and out to 500, shouldn't be more than a few inches
    Thanks for running that. Kinda figured there wouldn’t be a huge difference. Having a pretty easy to carry 22” bolt gun, the AR can probably be a bit shorter for convenience and not give up much.
  • knitepoetknitepoet Senior Member Posts: 17,075 Senior Member
    You're welcome.

    Those numbers have made me reconsider my long term plans on a AR10 as well
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • bullsi1911bullsi1911 Moderator Posts: 9,192 Senior Member
    I have a 16" barrel on my LR-308, and it works great for hunting, and I have hit on steel out to 500 yards.  If I was doing it over again, I would do 16 or 18".

    Plus, I'd try and build it lighter.
    To make something simple is a thousand times more difficult than to make something complex.
    -Mikhail Kalashnikov
  • JayhawkerJayhawker Moderator Posts: 13,764 Senior Member
    edited June 9 #16
    Great input Zee....
    I concur on the stock issue....I developed a intense dislike for adjustable stocks some time back and have been putting A2s on my gas guns.........if I need a short gun I'll grab my AR pistol....
    Sharps Model 1874 - "The rifle that made the west safe for Winchester"
  • MichakavMichakav Senior Member Posts: 2,098 Senior Member
    Zee said:
    So, my thoughts/suggestions.

    16” Barrel - I’ve handled the longer .308 gas guns and they just aren’t fun. At that point, give me a bolt gun. I’ve shot to 600 yards with both my 16” gas and bolt gun without issue. 

    15.5” Free Float Forend - it looks better and feels better. Plus, it gets the bipod out close to the Muzzle and adds stability when shooting with a rear bag. 

    Fixed Stock- Honestly, I’m gravitating towards a fixed stock for any and all ARs. A fixed stock is better from the bench and with magnified optics in general. I have an adjustable stock on my Colt 901 and hate it compared to the fixed stock on my built gun. 

    Geissele Trigger - Damn good triggers. 

    Magpul K2 Grips - More vertical and better for bench/prone shooting in my opinion. 

    Adjustable Gas Block - I wouldn’t build an LR-308 without one. 

    I agree 100% on the fixed stock. I have always liked them since I shot my first M16 in basic training. They fit me perfectly and are solid. The only reason I see for an adjustable (civilian use) is so others can get the LOP they need, like my kids...etc....
  • ZeeZee Senior Member Posts: 19,185 Senior Member
    Jayhawker said:
    .........if I need a short gun I'll grab my AR pistol....
    This. 
    "To Hell with efficiency, it's performance we want!" - Elmer Keith
  • horselipshorselips Senior Member Posts: 3,517 Senior Member
    I read somewhere that unlike AR15 platforms, the AR10s are not standardized. There's the DPMS model which includes them and a few others, but lots of other manufacturers are haphazard and proprietary about their specs and compatibility. 
    https://308ar.com/ar-10-308-ar-compatibility-reference-guide/
    http://www.calguns.net/calgunforum/archive/index.php/t-872423.html

    If I were in the market for an AR10, I would just buy a DPMS LR -308 or whatever their current offerings are designated. American Rifleman has tested the DPMS LR-308 and found it reliable and sub-MOA accurate. You can also find reasonably priced models like:
    https://www.gunbroker.com/item/774986816
    I've seen several go for the starting bid of under $600, and many for just a little over. No need to spend a lot to get a gun that will usually outshoot whatever you build on your own, for much less money, and it comes with a warranty. 



      
  • earlyagainearlyagain Posts: 948 Senior Member
    Being mostly ignorant and uninformed about such rifles I have to ask this.

    What's to recommend an AR10 over a DSA SA 58 FAL???
  • JayhawkerJayhawker Moderator Posts: 13,764 Senior Member
    Nothing really...two different platforms...pick what you like best....
    I will say that the AR10 is easier to modify to suit your personal needs considering the availability of after-market parts and there is no need to learn another manual of arms if you are already an AR shooter....
    That being said, the FAL has a cool factor all it's own...
    Sharps Model 1874 - "The rifle that made the west safe for Winchester"
  • MichakavMichakav Senior Member Posts: 2,098 Senior Member
    edited June 9 #22
    Being mostly ignorant and uninformed about such rifles I have to ask this.

    What's to recommend an AR10 over a DSA SA 58 FAL???

    For starters, price nowadays. The AR platform is highly customizable and can be had in literally hundreds of different configurations to suit each individual owner. A FAL is pretty much a FAL. Not knocking what they are as I really want one, but they are 2 different animals.
  • earlyagainearlyagain Posts: 948 Senior Member
    Thanks guys👍
  • cpjcpj Senior Member Posts: 37,368 Senior Member
    horselips said:

    I've seen several go for the starting bid of under $600, and many for just a little over. No need to spend a lot to get a gun that will usually outshoot whatever you build on your own, for much less money, and it comes with a warranty. 



      
    So is this coming from experience, or, are you talking out of your ass? I mean, I’m sure you’ve done accuracy testing of the guns you’ve built, so please share your results with the class. 

    "I'm here for the guns, hunting, and skirt wearing men."
    Zee
  • JKPJKP Senior Member Posts: 1,663 Senior Member
    Another vote for the fixed stock. I will likely not build another AR with an adjustable stock. Working on fixing (pun intended) a couple now. 
  • JayJay Senior Member Posts: 2,891 Senior Member
    edited June 10 #26
    Ok. You guys have me considering going fixed stock. That’s could be kind of cool. 

    Now, I’ll admit this, as petty as it might be. One thing that has always annoyed the heck out of me with the A2 stocks is the annoying SPROING sound the buffer spring makes inside of those stocks. Do the 308 guns do that the same as the AR15 A2s?
  • knitepoetknitepoet Senior Member Posts: 17,075 Senior Member
    edited June 10 #27
    I don't know what's changed, but I don't recall any of my current ar15 lowers "Sproinging"
    Some in the past did though
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • Diver43Diver43 Senior Member Posts: 7,599 Senior Member
    edited June 10 #28
    Strike Industries sells an after market flat wire spring that does away with the sprong while claiming to add performance and longevity for around 20 bucks. I can only verify the sprong is gone with one
    Logistics cannot win a war, but its absence or inadequacy can cause defeat. FM100-5
  • JayhawkerJayhawker Moderator Posts: 13,764 Senior Member
    knitepoet said:
    I don't know what's changed, but I don't recall any of my current ar15 lowers "Sproinging"
    Some in the past did though
    None of my ARs "Sproing" either...now that you mention it....though my old ones did......maybe we just don't notice it anymore...
    Sharps Model 1874 - "The rifle that made the west safe for Winchester"
  • knitepoetknitepoet Senior Member Posts: 17,075 Senior Member
    Jayhawker said:
    None of my ARs "Sproing" either...now that you mention it....though my old ones did......maybe we just don't notice it anymore...
    Possibly
    Seven Habits of Highly Effective Pirates, Rule #37: There is no “overkill”. There is only “open fire” and “I need to reload”.


  • Diver43Diver43 Senior Member Posts: 7,599 Senior Member
    edited June 11 #31
    Of my three, one sprongs, the others do not. I believe because of spring wire material and shape.
    The first rifle I ever shot (M-16 in basic) went sprong so it seems normal to me
    Logistics cannot win a war, but its absence or inadequacy can cause defeat. FM100-5
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