The perfect .308 AR

[DadSmith]

Is it sporting a carbine length gas system? Did you do anything special to make it cycle properly?

 

[daddyusmaximus]

Yes, it has the carbine length gas system. I ordered the JP Silent Capture recoil system that comes with 3 springs, so you can tune it, but the one that was installed in it ran fine right out of the box. The Enhanced BCG is supposed to help when run suppressed, and I do plan to one day, but for now, it just runs like any other, except maybe a bit softer. Then again, maybe it just feels softer because of the way it slows it down. The coating looks pretty, (LOL) and it sure as hell cleans up easily enough. I'm all for an easily cleaned BCG.

Forgot to say in the first post, the charging handle is a Raptor. Love them. Have one on my go-to Daniel Defense 5.56 pistol too.

 

[Rookie]

I've learned a little about this platform, or I should say, these platforms, because as stated: nothing is standardized.

I bought a stripped DPMS gen2 upper but can't seem to find any bcg nor barrel that works. Silly me, wasting the money. I knew beforehand and bought them thinking it would be easy to find.

Definitely staying with DPMS gen 1, and Aero seems to have a great following. I'm probably going to post some Aero stuff up in the longun classified later if you're interested. I won't be pricing it higher than what I have in them either. So check it out if you want to get into Aero.

Here you go...

https://www.msrhunt.com/post/compatibility-parts-list-for-remingtondpms-gii-8722882

 

[DadSmith]

Yes, it has the carbine length gas system. I ordered the JP Silent Capture recoil system that comes with 3 springs, so you can tune it, but the one that was installed in it ran fine right out of the box. The Enhanced BCG is supposed to help when run suppressed, and I do plan to one day, but for now, it just runs like any other, except maybe a bit softer. Then again, maybe it just feels softer because of the way it slows it down. The coating looks pretty, (LOL) and it sure as hell cleans up easily enough. I'm all for an easily cleaned BCG.

Forgot to say in the first post, the charging handle is a Raptor. Love them. Have one on my go-to Daniel Defense 5.56 pistol too.

Thanks for that extra information. I've entertained doing something similar but heard the horror stories about gas system problems. Iirc the DPMS 16" 308 ran off a carbine length gas system so it sounds like that might be the shortest you want if you want a gun that runs well.

 

[daddyusmaximus]

Thanks for that extra information. I've entertained doing something similar but heard the horror stories about gas system problems. Iirc the DPMS 16" 308 ran off a carbine length gas system so it sounds like that might be the shortest you want if you want a gun that runs well.

Don't get caught up in how "short" the gas system is. Typically the shorter the barrel, the shorter the system has to be. What matters is 2 things.

1. Dwell time. The amount of time the bullet is in the barrel past the gas port, but prior to exiting the muzzle.
2. Gas Port size. The diameter of the hole they drill out for the gas port itself.

These two things have to be matched well for a good running gun.

Some barrel makers get these right, others don't. Some will design a barrel for suppressed use... (more back pressure) Some, tend to "over gas" (make the port bigger) just to get their barrels to run. This will ensure you get the BCG to hold open on an empty magazine, but it's also what gives you a hard feeling recoil impulse. This also allows them to be reliable with crappy cheep low powered ammo a lot of people like to buy, then complain about when it doesn't work well.

This is where you get guys experimenting with different springs, and buffer weights... It can be daunting at times. In all honesty, I got lucky in that my combo worked well first time out of the gate. That's why I got the JP kit with the 3 springs, figuring I'd have to tune it. That's not to say I couldn't get it to works better with some tuning either, but it did work, so I haven't messed with it yet.

 

[Slow Hand]

Looks good! I e got a longer, heavier, accurate build I’ve mostly got running right and had thought about a smaller -10 like this for awhile. I found this one recently and it seems to tick a lot of boxes. I had some parts laying around to set it up mostly how I want it. I haven’t been Abel to get to the range with it yet but I have high hopes for it.



it’s a Diamondback DB10. 16” barrel and barely longer and heavier than my decked out Troy carbine.

 

[braydenw]

Really like the look of your AR OP! If it existed, I’d own a AR 10 in 8mm Mauser but sadly my dream will never be reality

 

[Hohn]

When someone makes an "AR10" in 6.5 or 7-08 that runs without hiccup the and isn't priced sky high like an SR25, let me know.

I was really looking into the Aero M5. Until the guy next to me at Atterbury spent the better part of his two hours with the receivers split and trying to diagnose an issue.

 

[Rookie]

6.5 creedmoor?

 

[daddyusmaximus]

When someone makes an "AR10" in 6.5 or 7-08 that runs without hiccup the and isn't priced sky high like an SR25, let me know.

I was really looking into the Aero M5. Until the guy next to me at Atterbury spent the better part of his two hours with the receivers split and trying to diagnose an issue.

Do you know what it was he was looking at? Mine is built on the Aero M5 receivers. You can't really go off that though. As long as they fit together, and hold all the parts together in the right place, more than likely that wasn't the problem. Most problems are magazine related, BCG problems, or gas, and recoil system not matched up correctly. There's always the chance it could be a receiver out of spec, and a Magazine not seating right, or the feed ramps off... but that's less likely. If it was a home build, it could have also been assembly problems...

 

[Hohn]

I didn't want to pry further beyond just asking if it was an Aero M5 because I'd been looking at them.
I'm a fan of Aero, and really want the M5 platform to be solid. But I keep hearing of hiccups here and there that give me pause, and then when I saw them firsthand I couldn't dismiss the online stuff so readily.

I'd agree that the problem is likely solved without too much difficulty. But an AR10 seems like it is NOT a turnkey operation at all like its smaller sibling. I think if I built one I'd need an A5 recoil system and adjustable gas block just to be able to tune it.

 

[MontereyC6]

I didn't want to pry further beyond just asking if it was an Aero M5 because I'd been looking at them.
I'm a fan of Aero, and really want the M5 platform to be solid. But I keep hearing of hiccups here and there that give me pause, and then when I saw them firsthand I couldn't dismiss the online stuff so readily.

I'd agree that the problem is likely solved without too much difficulty. But an AR10 seems like it is NOT a turnkey operation at all like its smaller sibling. I think if I built one I'd need an A5 recoil system and adjustable gas block just to be able to tune it.

My Aero .308 build had a slight issue. First time out, it was WAY under gassed. Apparently I had the gas block just a titch out of time. I ended up getting a jig and drilling a little bit for the set screw placement, and problem fixed. I've put right at 500 rounds down range since that day with out a hiccup.

All that being said, my Thompson Machine 30Ti suppressor has been recently approved. Once I'm able to pick it up, I'm sure I will have some tinkering to do with the gas once again, once the can is installed.

 

[NICKT93]

I put together the perfect .308 AR. I've posted a photo of if before, but I haven't explained the build yet.

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. As 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, and not that I would be able to justify any long distance shooting in any court... I just wanted something with a bit more oomph than the 5.56, or should things go really bad, 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 too building 10" .308 pistols 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. I lose some velocity, and power going down to 14", but not as 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. 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 really like the ACSS reticle.

I picked up a CMMG (1st gen i think) on the cheap, it seen better days but the deal , i couldn't even build an Anderson or PSA ar15 for the price was unbeatable. Your build is very very nice and inspiring me to go the same route , I haven't purchased any optics yet so really have all options open. Thing runs like a champ tho.

Again sweet build!

 

[FN USA]

Great looking rifle! I've been playing around with the idea of building one myself but expensive hobbies prevent that!

 

[DadSmith]

Don't get caught up in how "short" the gas system is. Typically the shorter the barrel, the shorter the system has to be. What matters is 2 things.

1. Dwell time. The amount of time the bullet is in the barrel past the gas port, but prior to exiting the muzzle.
2. Gas Port size. The diameter of the hole they drill out for the gas port itself.

These two things have to be matched well for a good running gun.

Some barrel makers get these right, others don't. Some will design a barrel for suppressed use... (more back pressure) Some, tend to "over gas" (make the port bigger) just to get their barrels to run. This will ensure you get the BCG to hold open on an empty magazine, but it's also what gives you a hard feeling recoil impulse. This also allows them to be reliable with crappy cheep low powered ammo a lot of people like to buy, then complain about when it doesn't work well.

This is where you get guys experimenting with different springs, and buffer weights... It can be daunting at times. In all honesty, I got lucky in that my combo worked well first time out of the gate. That's why I got the JP kit with the 3 springs, figuring I'd have to tune it. That's not to say I couldn't get it to works better with some tuning either, but it did work, so I haven't messed with it yet.

Thanks for that information.

I've always wanted something similar to what you have built there. My last build was a 6.5 Grendel 20" barrel. I'll have to get this back on the to do list.

 

[Hohn]

Don't get caught up in how "short" the gas system is. Typically the shorter the barrel, the shorter the system has to be. What matters is 2 things.

1. Dwell time. The amount of time the bullet is in the barrel past the gas port, but prior to exiting the muzzle.
2. Gas Port size. The diameter of the hole they drill out for the gas port itself.

These two things have to be matched well for a good running gun.

Some barrel makers get these right, others don't. Some will design a barrel for suppressed use... (more back pressure) Some, tend to "over gas" (make the port bigger) just to get their barrels to run. This will ensure you get the BCG to hold open on an empty magazine, but it's also what gives you a hard feeling recoil impulse. This also allows them to be reliable with crappy cheep low powered ammo a lot of people like to buy, then complain about when it doesn't work well.

This is where you get guys experimenting with different springs, and buffer weights... It can be daunting at times. In all honesty, I got lucky in that my combo worked well first time out of the gate. That's why I got the JP kit with the 3 springs, figuring I'd have to tune it. That's not to say I couldn't get it to works better with some tuning either, but it did work, so I haven't messed with it yet.

This is a good post. I would say that the gas system length isn't *totally* irrelevant though. Because the shorter systems use higher port pressure. And this means that the "proper" amount of gas must be more precisely metered. (pressure times volume is the potential energy of a gas, so more pressure means less volume. And smaller changes in volume for a given energy change).

Can a short system work reliably? Absolutely. It just has a narrower range of "ideal" so it may require more consistency in ammo and cleanliness and other such variables.

 

[jag09]

I know alot of people aren't fan of piston driven systems but my 308 AR from PWS has basically ran flawlessly. I've had one issue but that was solved by swapping out a bad magazine that wouldn't run in a friend AR10 either. I purchased their MK216 MOD 1-M rifle some years ago and its still chugging along great

 

[daddyusmaximus]

I know alot of people aren't fan of piston driven systems but my 308 AR from PWS has basically ran flawlessly. I've had one issue but that was solved by swapping out a bad magazine that wouldn't run in a friend AR10 either. I purchased their MK216 MOD 1-M rifle some years ago and its still chugging along great

I'm glad it worked out well for you, but I'd be too nervous to run a weapon that uses one off proprietary parts. The .308 world is bad enough already with 2 different standards depending if you go with the Armalite, or the DPMS pattern guns... last thing I would want is something that wasn't one of those two, just on the off chance that I ever needed parts for it at an inopportune time.

Same reason my 5.56 ARs are all DI guns.

And my .300 Blackout, and why it's not my go to gun. It's non-standard.

 

[MikeHoncho]

I like it. I have a 16" Windham Weaponry that does me well. Very handy for deer hunting around here.

 

[JUGGERSEVENSIXTWO]

What is the weight of your rig loaded?any plans shooting suppressed?I had a POF it was just to heavy for my liking.
recoil was great.They can really lay down a field of fire when needed.I had the same optic on mine.