3Gun AR build help and opinions

[JordanGriffith]

Hey guys. Look g at building or buying another rifle dedicated for 3 gun. Thinking about building one and doing it over the next few months (easier to spend slowly than have my wife shocked with a $1600 purchase [emoji6])

Looking for pointers and advice.

So far I'm planning on an Ace skeleton rifle stock, 15" keymod handguard, 18" barrel (probably stainless fluted, unless you guys have better suggestions)

Looking for good info and recommendations on a trigger, BCG, gas system and buffer. I know a fair amount about the guns, but I see a lot of debate over what the best combinations are for reliability speed and recoil.

I already have an extra JM Compensator and I plan to use that because I love the one on my AR now.

Thanks in advance everyone!!

[Steve RA]

I'd suggest a Nordic 18" barrel without flutes. I got one from Carbon Arms and it is turning out to shoot very well. I also got their gas block and tube. I'm running a stock bolt carrier and bolt and using a self contained spring set up from JP.

[morpheus]

Stretch 16 barrels are very good as well

[JordanGriffith]

Why not a fluted barrel?

[michael1778]

Why not a fluted barrel?

Jordan, what is your particular motivation for a fluted barrel?

I'm considering making a lighter weight 16" upper for competition, so in my particular case, I'm looking for modest weight savings. I'm starting with a 16" barrel as a baseline for the design. My 18" Criterion hybrid contour barrel is fine, but I want to change the balance and total weight of my rifle. The fluted versions of the Stretch 16 look like the best balance for recoil management (through gas system length) and weight.

So, why a fluted barrel for your intended use?

[JordanGriffith]

well because it cools faster and is lighter than a heavy barrel/bull barrel. Most of the competition ready guns, example the Stag 3G come with fluted stainless barrels. I wanted to go with an 18" for a little more accuracy over the 16". I'm 6'3" but I have a long wingspan for my size and with my carbine barrel the 15" rail puts me close to compensator and I'd like the extra few inches of clearance as well. I've considered buying a cheap factory gun like a M&P sport and buying the add ons too, but I'm changing so much I think it's cheaper to buy a stripped lower, good trigger lower parts kits, ace stock, and a complete upper with the handguard and barrel length in looking for.

Any advice on gas system length, buffer setup and BCG

[michael1778]

I'm 6' 1" with above average arm length. I can relate completely! And I really don't like getting blasted by my compensator. Oh, don't forget to look at the length of pull (LOP) for your stock set-up. You may feel cramped in some situations. I don't have enough experience to give definitive guidance, but I do know that some stocks feel awkward. I think they are too short for me.

Are your hands large too? You may need a larger grip like an Ergo Tactical Deluxe, some of the Magpul grips with changeable back straps, or a forward-set flat-faced trigger. Maybe even a combination of all three. Personally, I run an Ergo Tactical grip and am about to change to a CMC flat trigger to get it out just a bit more for finger placement. Should put it right on my trigger finger pad

Given that I once bought an M&P15 Sport and then modded it up, I thin you are on a better track by a more custom build up front. It really isn't that much more expensive than a base gun and modding it up, in my opinion and experience.

With regards to the cooling aspect of fluting, for this game, I'd recommend you not give that much significance in your decision. Weight reduction? Sure thing. Plenty of people with deep engineering backgrounds as well as shooting experience will say generally the same thing on here. They may be along as time goes by to comment. Perhaps the JP Thermal Dissipator would give more cooling. I tend to buy the engineering description as well as some personal feedback I've received form users. But, I still think that is marginal and chasing insignificant improvements in most situations.

So, either an intermediate length gas system (Stretch 16 barrel) or any number of rifle length gas barrels (Nordic, JP, Black Hole Weaponry, and the list goes on) 18" and above. Please remember that accuracy is not a function of barrel length; however, velocity is. Faster bullets don't have as much time to be deflected by wind over very long ranges. That isn't accuracy. That's "wind resistance" giving less dispersion under variable wind conditions.

On my 18" barrel I use an adjustable gas block. My Bolt Carrier is a JP LMOS with QPQ finish. I use a 'stock out of the box' JP Silent Captured Spring system. I hate the rasp of more common buffer springs.

I splurged and bought the expensive JP Enhanced Bot to go into the JP LMOS carrier. That was a spendy thing for me to do.

Look at hand guards longer than 15" if you get an 18" barrel. With those long arms you may like that ability to reach out. 15" is about minimum for me, so I suspect you might like something 16.5" or 17". You'll have to be the judge on that one.

I hope this is helpful for you. All the best wishes in your build.

[JordanGriffith]

Thanks! Very helpful. The worst thing for me is, where I live there isn't much for looking at things in person. Not many people around hear have any aftermarket triggers I can try either. Right now I'm running a magpul stock on my Bushmaster/Frankenstein rifle, and I think I'm just going to order the longer Ace skeleton stock and try it out since no stores here carry them.

My buddy thinks it's more expensive to buy all the pieces. But really most of the things on a factory rifle are going to be replaced. What's the best buffer weight to use?

[michael1778]

Build your own lower receiver assembly and have a good shop do a competition upper, perhaps? Carbon Arms would be one route to go for a great upper. I have one in 16" and it's a heck of a shooter. Proven sub-MOA before it was shipped to me. It held up that performance even with me behind the trigger!

I haven't played around with buffer weights, yet. Couldn't give any feedback on that. I simply inserted the JP SCS and went off to the range. I guess I could optimize it somehow, but no interest in that just yet.

If you replace the barrel, gas block, stock, hand guard, grip, muzzle device, buffer, buffer spring and bolt carrier you would not have much of the original rifle left. Just the receiver set, upper parts kit, lower parts kit, and the buffer tube (receiver extension) would be left. Oh if you to the ACE stock then you have to change the buffer tube also.....so just the receiver set and the two parts kits. M&P15 Sport is what, about $600? Hmm, that's an expensive assembled receiver set. I would encourage your friend to recheck his financial assessment.

[JordanGriffith]

Yeah haha I agree. I'm not sure if it's worth me getting crazy on low mass BCG and all that, I don't think I can out run a factory AR, and with that Jerry Miculek compensator it has hardly any recoil as it is.

Any trigger suggestions?

[michael1778]

JP LMOS isn't too silly in low weight. I think it's worth getting. Then, just put in a normal bolt that is properly head spaced for your barrel.

Triggers are *so* personal. But, I'm switching from an AR Gold to a single stage CMC flat trigger. I think the resulting position will be excellent. A full, deep grip with the slightly forward flat trigger should do the trick. I think the AR Gold may end up in a future precision rifle.

The CMC flat is not expensive. That should reduce financial risk. But, triggers are very personal.

[JordanGriffith]

Yeah I've heard good things about Elftmann Tactical triggers

[KSwift]

My opinion on things like this is to buy everything used and take what you can get a deal on. Don't get too hung up on a particular brand/model of a certain item if a very similar one is available for a good bit less. Once you get to the level where those exact items matter more, you'll be able to get all the exact gear you want.

You said "building or buying another rifle dedicated for 3 gun". What was/is wrong with your other AR?

[JordanGriffith]

Nothing's wrong with it, it's got a shorter barrel than I want and needs a trigger. But that one was built for plinking and shooting coyotes

[Steve RA]

In addition to #2 above:

I've got an Ace stock, the large grip and a CMC flat trigger.

[JordanGriffith]

Perfect Steve! I'll take it[emoji41]

[Steve RA]

Sorry, I really like the LAR side charge upper, but, unobtanium since Remington bought LAR. Crosshill makes one almost identical which JoeBob's handles if anyone can't live without one.

[JordanGriffith]

What scope are you running?? I always wanted a Grizzly LAR lower

[Steve RA]

Primary Arms 1X6 with an Aero Precision mount. I'm using that mount as I don't plan on needing to change scopes around and it has no protrusions on the left side. Sorry about the LAR lower.

[JordanGriffith]

Haha that's ok. Spikes tactical spider lowers are cool look too. I just wanted a lower with a grizzly on it.

How do you like the ace stock? Can you use a standard mil spec buffer tune with them?

[Steve RA]

Really like the stock, yes you can use a standard buffer with it. I'm using a JP self contained spring set up which I really like. Seems to be really smooth and doesn't "Twang".

[JordanGriffith]

So I can just slide my magpul stock off and slide this one on??

[TonytheTiger]

If you currently have a collapsing stock the Ace will not slide on. You'll need an A1/A2 buffer tube.

[Steve RA]

True.

[JordanGriffith]

That's what I figured. Idk why they do t sell them with the buffer