The perfect .308 AR

[daddyusmaximus]

I put together the perfect .308 AR. I've posted photos of if before, but I haven't yet explained the build. I also got help with it during the build on the .308 knowledge thread, so to all who chimed in... thanks.

Now keep in mind, when I say that it's the "perfect .308 AR", I mean it's the perfect one... for me.

I was looking to get into a .308 because I wanted the better terminal ballistics of the heavier round.

What I didn't really need, was the increased range.

This was to be a defensive combat carbine. It was to be "defensive" in nature, it's not one I would need to reach out long distances, at least not in my area, (Indiana woods, and farmland) I just wanted something with a bit more oomph than the 5.56, or should things go real bad, have the ability to punch through cover better.

I did still want to keep it in as small, and light a package as I could. I like a patrol carbine, not a full on sniper rifle.

On the other hand, I've seen guys go way too far with the "smaller is better" theory when building 10" .308 pistols and the like, that though probably fun to play with, would pretty much cut the .308 off at the knees.

I tried to make a decent compromise, and I'm pretty happy with the result.

Receivers... Aero Precision with their LPK
Barrel... BA Hanson 14" with pin-and-welded Warcomp
Rail system... Midwest Industries
Scope... Primary Arms 1-8 with the ACSS reticle
BUIS... Troy with tritium
BCG... Lantac enhanced
Recoil system... JP Captured
Trigger... Geissele SSA-E
Furniture... Magpul CTR stock, MOE grip, MVG M-LOK
Weaponlight... Surefire M300 Scout Light
Leftover ambidextrous safety that I can't remember where I got...
Leftover scope mount... same deal... just happened to work out well.

Anyway, the end result is the rifle is a bit heavier that the typical AR (as expected being a .308) but still very easily carried as a patrol carbine. In fact, the 14" barrel matches up with the larger .308 receiver so well, it's not really any longer than a 16" 5.56 AR.

I lose some velocity, and power going down to 14", but not so much as going crazy, and doing the full on SBR 10" thing. It still packs a lot more punch than a 5.56. It's very controllable too. Not sure if that's because I'm a big dude (6'1" 280) with 28 years of Army experience, or the very effective Warcomp (probably both) but I like it. I like it a lot. I really like the ACSS reticle too.

I've only managed to take it out a few times since it's completion, but it's been 100% reliable in those times so far. Hoping it will stay that way. The BA Hanson barrel is supposed to be a 1" guarantee of accuracy. Well, I've seen close to that, but I haven't seen that. At least not yet. Not gonna say I got a dud though because it's probably me, but it's close enough that I'm not gonna complain. Besides, we all have this "every single gun must shoot 1" groups" mentality these days, and for a patrol carbine just being close to that is great in my book. Especially in the hands of a mid 50s retired half cripple.

Also of note is the barrel twist. It's a 1/10. Everyone makes barrels in 1/10 these days for the heavier rounds. I got my hands on a stash of the 130 gr Federal T762TNB1 made for the Army's short barrel SCAR project as I figured a short barrel round would do well in my little 14"gun. but turns out it's quite expensive to find an AR barrel in 1/12 twist... It shoots the heavier rounds better. However, at close ranges, it's still plenty accurate.

[dpb1776]

Sweet build


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[fedupflyer]

Is that a 3 prong flash hider?
When shooting suppressed, I hate those things as they sound like a tuning fork.

[CoryCop25]

Very nice set up! I may need to start a similar project.
That a SF Warcomp. It doesn’t “ring”.

[daddyusmaximus]

That's a Warcomp. It does in fact ring, if I bang it up against something, yet no ring when shooting... go figure.

[LMT Shooter]

Very nice rifle, I've been wanting to get a MWS with the 13.5" lightweight barrel for similar reasons as you stated.

[NQNPIII]

I would like to buy/build another .308 upper. You got me thinking. I have a spare Gen2 PSA lower. I was considering going into one of those 6.? calibers. Maybe not a good idea. Might just stick with .308.

Any guestimates on the muzzle velocity? The reason I'm asking is it is possible to got to a 13.X barrel and pin and weld it to be "legal."

Looks like you and I have the same scope. Mine is on a PSA 18" Gen3. I got mine in a blem sale for less than $300. PA1-8X24SFP-ACSS-5.56. How far out does that scope stay clear? I have only been out to 50yds so far. My favorite rang goes all the way out to 330 meters. Due to all the recent rain you need to have waders on to get out that far.

[daddyusmaximus]

I would like to buy/build another .308 upper. You got me thinking. I have a spare Gen2 PSA lower. I was considering going into one of those 6.? calibers. Maybe not a good idea. Might just stick with .308.

Any guestimates on the muzzle velocity? The reason I'm asking is it is possible to got to a 13.X barrel and pin and weld it to be "legal."

Looks like you and I have the same scope. Mine is on a PSA 18" Gen3. I got mine in a blem sale for less than $300. PA1-8X24SFP-ACSS-5.56. How far out does that scope stay clear? I have only been out to 50yds so far. My favorite rang goes all the way out to 330 meters. Due to all the recent rain you need to have waders on to get out that far.

1. MV... No clue. I don't have a crono. I did get me a stash of that 130 gr Federal T762TNB1 made for the Army's short barrel SCAR. That's a 13" gun, so it should do very well out of my 14" gun for genneral purpose defense work. It like the heavier rounds (168gr) though for better accuracy due to the 1/10 twist.


2. Clear scope. I haven't shot the thing on anything but the zero range, and a 100 yd DNR range, but I've carried it around , trained, and glassed with it. I can see farther than that with it on my own property. The scope is plenty clear for the money it cost, so any limitations it has will be my not so great sight. I'm sure the higher end scopes are more durable, and have more accurate dials, but you don't buy something with the ACSS to use the dials. #notasniper.

Even with 8 power, I figure this for a 300 or 400 meter gun at best just based on my own limitations. My eyesight is probably off more than the short barrel will effect the ranging of the reticle, but that will factor in, especially farther out in the .308's rainbow trajectory. However, I never had a chance to test out the exact ranges, and how bad it's off prior to everything shutting down.

[Nightvisionary]

What does it weigh? My 16 inch FAL had such an outrageous muzzle flash/blast I went to a 20 inch barrel when I purchased a DPMS G2 AR10. 1.5 inches longer than a 16 inch 5.56 AR and sub 7.25 lbs unloaded with a carbine receiver extension.

[Failure2Stop]

1. MV... No clue. I don't have a crono. I did get me a stash of that 130 gr Federal T762TNB1 made for the Army's short barrel SCAR. That's a 13" gun, so it should do very well out of my 14" gun for genneral purpose defense work. It like the heavier rounds (168gr) though for better accuracy due to the 1/10 twist.

That ammo is actually from a Crane (NSW) SOCOM program, not really "the Army's" SCAR, nomenclature Mk 319 Mod 0.
https://ndiastorage.blob.core.usgovc...ioniii8524.pdf
It's used quite a bit with 16" 7.62 guns, and it is a pretty solid terminal performer, but 1.5-2 MOA average. MV from my 14.5" is 2650. I have killed a lot of feral hogs and javelinas with it out to around 400. A 1 in 10 twist rate is not at all detrimental to the projectile's precision potential, and in fact a little faster would be better.

When it comes to application of the short barreled 7.62 guns, the issue is way less with the trajectory/drop, and way more to do with wind effect. Ballistic calculators will very reliably tell you where the bullet is going to go at a known distance, but you're going to have to figure out the amount of wind in effect and compensate more precisely than with a faster projectile. I've shot 14.5" and 16" 7.62 rifles to stupid far distances, but I do agree that in practical application with the 130gr SOST, it's a 500 meter gun.