New to gas guns, 6mm arc build advice

Freediver111

Sergeant of the Hide
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Feb 28, 2018
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I’m totally new to semi auto rifle builds so I have a few basic questions. When I say new to them I mean totally green. I own some semi 22lr’s and shotguns, but haven’t played around with very many semi auto rifles.

Not in any rush, but I’m thinking about a new build/purchase. I have plenty of precision bolt rifles, but never messed around with semis. Looking at 6mm arc for the chambering. Goals are an accurate platform for plinking out to 1,000, but also useful to hunt deer/coyotes with. I would be reloading for this, and prefer something on the lighter weight side for hunting.

Is it worth buying a complete rifle, or buy in pieces over time? I don’t have a budget at the moment, but I’m not necessarily budgeting on the highest end. Lowest cost without sacrificing performance I guess.

I’m thinking a 20” barrel, and would use it with my TBAC U7. Likely add a butt stock with adjustable cheek pad, and top it with something in the 4-18 mag range scope.

Looking around it seems there are plenty of uppers in the $600 range, but I have no idea if that’s a low end price for an upper or what? I don’t need the fanciest upper on the market. I don’t really care if it doesn’t have all the bells and whistles, but if it isn’t a reasonably accurate gun then I’ll be disappointed. Yeah, I know a semi won’t be as accurate as my bolt guns, but somewhere in the 1 MOA range of accuracy would suffice.

I see some uppers like Atheris offer adjustable gas block options. Is that a must or a luxury? Other than the upper what would you recommend to round out the build if you were to buy parts and build yourself?

Thanks for any advice.
 
I would do 20" at least. Ballistic Advantage are good and reasonably priced and Proof are usually great (carbon fiber option, too). I would do an adjustable gas block if you are interested in different loads for different uses and running a suppressor.

JFR
 
If you are new to the ar platform, have the funds, and are shooting suppressed, save yourself a bunch of heartache and buy a complete factory rifle with an adjustable gas block. Several manufacturers make them with simple switchable gas blocks for shooting suppressed. I wouldn't advise learning about ar rifles by trying to assmble one one at home and trying to figure out how ti make it cycle. 15% of the threads on the hide are people failing at exactly that.
 
If you are that green towards them then I’d recommend buying for your first. However, building them isn’t that difficult but most people who are new to ARs don’t know what they like/dislike. Building for most of us makes the most sense because we already know exactly what parts we want. I we buy a pre built factory rifle, then we are paying for some parts that we will swap out right away. We also have all of the necessary tools and can spend the extra time and care to try the receiver face, bed it etc.
 
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I’m not set on building vs buying a complete rifle. I like to tinker, but sounds like I’d have a little easier time just going with a complete gun.

It seems like AR’s are all over the map price-wise. I’ve looked at some nice guns in the $2500 range, but there’s plenty out there for $1,500 that I can swap parts as I get familiar with what I want. Do you have any recommendations in the middle of the pack price ranges? Like I said, I don’t need the best of the best for this one, but also don’t want crap.
 
Cmmg makes a decent rifle. Seekins makes a spectacular rifle that I believe can be had for less than $2k. If you buy quality parts and make your own, you'll blow right past that and probably won't have near the rifle.
 
Cmmg makes a decent rifle. Seekins makes a spectacular rifle that I believe can be had for less than $2k. If you buy quality parts and make your own, you'll blow right past that and probably won't have near the rifle.
Just given a Seekins for my Bday. Looking foward to it. Love my SP-10. FWIW Seekins did a special run of 6ARC 18” guns for BattleHawk Armory. $1699. Incredible price IMO.
 
I’m not set on building vs buying a complete rifle. I like to tinker, but sounds like I’d have a little easier time just going with a complete gun.

It seems like AR’s are all over the map price-wise. I’ve looked at some nice guns in the $2500 range, but there’s plenty out there for $1,500 that I can swap parts as I get familiar with what I want. Do you have any recommendations in the middle of the pack price ranges? Like I said, I don’t need the best of the best for this one, but also don’t want crap.
If you buy a cheap AR, you might end up spending the price of the gun on upgrades. $200 or so for a trigger, $100 for a good AGB, $150 for better barrel etc.
 
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If I wanted a 6MM ARC, I would build one. That said, I have all the tools to do that.

Do you know anyone with the tools ?

A quality upper and lower , with a snug fit between the 2, and a thermal fit upper.

A decent 2 stage trigger ( Schmid Tool )

I would buy the best barrel I could afford for sure, it is a precision oriented round. And AR's can shoot tiny as_ groups. .. so why not spend a little more to help get that better accuracy. As mentioned above you could spend that much on ammo just trying to make a lesser quality barrel shoot to your expectations.

Otherwise... I would be tempted to try one of LaRues 6MM ARC's... but it is only a 16" barrel.
 
I'm shooting an 18" and 20" out to 1200 yds with 108 ELD-Ms. Both achieve 1200 yds insanely easily. I might even choose a 16" if I was just going out to 1K and hunting suppressed.

Larue just came out with a complete 16", 6 ARC upper. I know of a couple of "Grendel Hunter" uppers which have had great reviews. Grendel Hunter has a variety of barrel lengths.

My 9 year old son hunted his first white tail hunt with a 20" suppressed (Omega 300) 6 ARC, and after lugging that around, I would definitely consider 18" or 16" barrels.
 
Just given a Seekins for my Bday. Looking foward to it. Love my SP-10. FWIW Seekins did a special run of 6ARC 18” guns for BattleHawk Armory. $1699. Incredible price IMO.
Larue is supposed to make a good product. I've never run his rifles, just his mounts. But if they're any indication of quality and reliability then go for it
Screenshot 2023-02-21 at 08.40.38.png
 
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S&W, Santan, CMMG, and Seekins all make 6mm ARC rifles. The Seekins would be my choice given I was impressed by their large frame gas guns.

The S&W has a $100 mail in rebate going on until 4/2.

If I were to build, Vltor upper, Proof barrel 130384, Seekins lever adj gas block and a rail like the BCM KMR/MCMR. Option 2 would be the Seekins IRMT-3 or R upper, same Proof bbl and gas block. You will have to use the Seekins rail with those uppers but will have a solid system. A 15" rail should give you plenty of room to use the gas block's lever.
 
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Hopefully my 2 cents isn’t too late….. Compass Lake builds a fantastic upper, mine has a Douglas barrel and it’s outstanding. I’ve heard nothing but great things about Dtech uppers as well. The big thing would be for me is buy a JP Enterprise bolt from Compass or send one to Mike at Dtechuppers.com. The 6mm ARC is tougher on bolts than the original 5.56. The lower is so easy and fun to build don’t miss out. A LaRue trigger is your best bet. Go for a mom & pop builder that lives off reputation and only uses quality match barrels. They both have nice float tubes that are stiff, well made and are reasonably priced. Also they have a reliable recipe with the gas system so you really only need to check which buffer weight to use. Especially shooting out as far as you’re talking about you’ll be much happier with a match level AR especially since you’re coming from bolt guns. One other thing you can send an upper receiver of your choice to Compass or Dtech. I’m really happy with my Iron City Hatchet billet receiver set, it has a very tight fitment no wobble which is good especially coming from bolt guns. A bit larger ejection port for the bigger 6mm ARC case, a thicker wall around the thermo fit barrel extension. I believe Iron City is a great value for the quality. That’s comparing my Colt, JP Enterprise(billet) and V-Seven receivers. Lastly try a AR out and if the recoil spring noise bothers you like it did me buy a JP silent capture spring.
Cheers
 
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