3 ARs in 1 Build

[treillw]

I want to build an AR with a few uppers. There are my thoughts:

• A really nice lower with a good trigger. Probably get the SBR stamp.
• A standard 5.56 upper (probably 16" or 14.5" pinned) for defense. Probably doesn't need to be anything too fancy.
• A 300 BLK upper with an adjustable gas block. Short barrel. Turn the gas block off to essentially turn it into a bolt gun and have it be as quiet as possible for subs. Turn the gas block back on for supersonics and typical defense operation.
• A long range upper. The 243 WSSM sounds like a ton of fun. Coyotes, deer, antelope, wolves.

I know enough about ARs to be dangerous, but never got into them too heavily. Any advice to make all this go smoothly? Does it matter if the uppers are the same manufacturer to aid in fitup, etc?

Who makes the nicest lowers? I'd think to go better quality on the lower and long range upper/barrel. The BLK and 5.56 could probably be more military grade.

A defense trigger and a long range match trigger aren't exactly the same animal - dunno if this will cause any grief.

Does your optic zero shift at all when switching between uppers? I know the optic is fixed to the upper, but does anything else change similar to resetting the barreled action in a bolt gun? I'd imagine the change would be pretty minimal, if present.

What components would you use? Build or buy?

Clarification: I don't intend to build them myself without help from a gunsmith, etc.

Thanks!

 

[sndmn11]

I'd build it as a 300BO pistol first. My last several have been Aero parts.

 

[wind gypsy]

I'm not much of an AR guy but i've got a few.

I have a timney single stage trigger on a heavy 20" that is more precision oriented and a Larue 2 stage in a 14.5" fightin type AR. I like the Larue better and it's cheap. That's probably what I'd use.

 

[BRTreedogs]

Radian
Gelisske trigger

 

[KHNC]

Look at Tactical Solutions. I have a TSAR 300BLK with a Silencerco Omega 30. Very nice! Trigger is pretty good, but the feel of everything is nice, even when i change out the uppers.

 

[Formidilosus]

I want to build an AR with a few uppers. There are my thoughts:

• A really nice lower with a good trigger. Probably get the SBR stamp.

Lowers are lowers for the most part. The ones you see with cutouts and sharp edges are billet lowers versus forged which is standard Milspec. I prefer forged lowers greatly over stylized billet lowers. If you wanted to get a lower that actually offers functional advantages, the LMT MARS-L lower is the one- full ambi done right.

• A standard 5.56 upper (probably 16" or 14.5" pinned) for defense. Probably doesn't need to be anything too fancy.

Fancy no, but a stiff free float rail, quality legit Milspec BCG- yes. Again if you want more than basic, the LMT MLR or MLC upper is the “best” functional setup.

A long range upper. The 243 WSSM sounds like a ton of fun. Coyotes, deer, antelope, wolves.

The barrels do not last long at all. I am not a person that cares about barrel life, however the several we had lasted around 400 +/- rounds before groups opened significantly. Granted that was some competition use, but something to consider. The 6ARC is really where the small frame AR’s are for long range use. Very good factory ammo, good precision, good ballistics, and good barrel life.

I know enough about ARs to be dangerous, but never got into them too heavily. Any advice to make all this go smoothly? Does it matter if the uppers are the same manufacturer to aid in fitup, etc?

It does not generally matter if the upper and lowers are the same manufacture, however with some billet setups it does. If you stay with standard forged uppers and lowers you should be fine.

Who makes the nicest lowers? I'd think to go better quality on the lower and long range upper/barrel. The BLK and 5.56 could probably be more military grade.

Functionally, LMT MARS-L.


As for the uppers, getting things that just work with no fuss takes a certain level. More than likely you will shoot the 5.56 more than the other two combined, so I would proffer that it should be setup to work and shoot very well.

Again, for small frame uppers the LMT MLR monolithic uppers are the most “advanced” if you will of the AR platform. Reliability, durability is excellent, and precision is quite good.
If not a monolithic upper, then I would look at the Hodge Wedgelok for a handguard- they are the best feeling handguards on the market. 14.5” over 16” for anything defensive, would actually heavily suggest 12.5” for that use- with a suppressor; or if not going to suppress than a Surefire Warcomp muzzle device- very good flash suppression with good recoil and muzzle compensation. Pay attention to gas port sizes and go either chrome lined or melonite.

Bolt carrier groups need to be Milspec or better. Lightened, adjustable, or other tinker toy BCG’s are just a pain. Straight up Milspec BCG with an H2 buffer and correctly gassed barrel should run without issue.

A defense trigger and a long range match trigger aren't exactly the same animal - dunno if this will cause any grief.

Not really. Cassette style triggers have much more issues than non cassettes. Geissele two stage or Larue MBT two stage is where you want to be.

Does your optic zero shift at all when switching between uppers? I know the optic is fixed to the upper, but does anything else change similar to resetting the barreled action in a bolt gun? I'd imagine the change would be pretty minimal, if present.

No.

What components would you use? Build or buy?

Buy- LMT monolithic upper and LMT MARS-L lower if you want to spend more to get more. If not, quality forged lower and upper.

 

[2Stamp]

FWIW, a few other options on good lowers (if you can find them) are Sionics, Spikes, Bravo Company and Sons of Liberty.

 

[Adam Gibbs]

I'd forego the 243wssm upper and just build either a other 5.56mm upper more suited to hunting or just hunt with your 14.5" or 16" 5.56 upper. Anything you listed can be killed with 5.56 just fine.

Then you'll have ammo and mag commonality.

 

[menhaden_man]

I’d swap 243 for 6.5G myself. Looks like the ARC is better but I’ve got a pile of brass and components for the Grendel.

300 AAC
223 Wylde
6.5 Grendel

Build yourself, it’s not hard and you’ll learn a ton. Good luck!

 

[CHSD]

If you are going to SBR your lower I would get a 10.5 inch barrel for defense. It is a lot less cumbersome than a 16 inch barrel.

I am a big fan of the Larue triggers! I would take a hard look into getting one.

Also I may get flamed for this but PSA makes some good stuff. Their CHF barrels have been very good for me. My dad has a Larue which shoots lights out, but my psa CHF barrel is not far behind.

If I were you I would buy three lowers for all three of your uppers. I wouldn't be afraid to throw uppers on some poverty ponies or psa lowers. I wouldn't want to mess around with swapping uppers. For sure I would get a separate lower for your defense rifle. And maybe swap the other two uppers. Would hate for a need for the defense rifle to pop up and you've got the .243 upper on. Even thought that would probably make fore a wicked defense gun lol.

 

[Loebs]

Have and 18" in 223 Wylde for my girls to start shooting with. Forged mil-spec lower. Nothing fancy, but a trigger swap to help them learn. Going to put together a 6.5 Grendel upper for this year's antelope season. Could they shoot some 77SMK's, yes. But dang it is windy where we hunt and I want something that will buck the wind a bit better for them. This is their first year hunting with a center-fire and I want to put together a point and shoot rifle for them with out having to teach them how to call for wind yet.

Sent from my motorola one 5G using Tapatalk

 

[justinspicher]

I did this same thing a few years ago and bought an 11.5” 556 upper from KAC, built an 8” 300BO, and built a 16” 6.5 Grendel. All three run off my KAC lower (it is tax stamped for use as an SBR). I also purchased a Silencerco Omego for use on all three rifles, as they use the same ASR mount for a brake.

 

[treillw]

I did this same thing a few years ago and bought an 11.5” 556 upper from KAC, built an 8” 300BO, and built a 16” 6.5 Grendel. All three run off my KAC lower (it is tax stamped for use as an SBR). I also purchased a Silencerco Omego for use on all three rifles, as they use the same ASR mount for a brake.

Do you have any issues with the buffer spring on the lower not mixing for all of those calibers? I've read some stuff that they won't play well together.

 

[h2so4]

Noveske fan here.. They are expensive and kind of fancy- but many other quality options exist that will work just as well.

I like the adjustable gas block, especially for a 5.56. But not sure why would want to turn it into a bolt gun with 300BO subs. I guess maybe if you're at the range and want to work targets without burning through ammo?

Once you built the first lower and 2nd upper, you'll likely start another build for a different application- long range, etc. It's just fun and usually how it goes. The Geissele SSA or SSA-E triggers are a good starting point, too.

A long while ago I remember looking at "my first AR" threads and a resounding theme was the Colt 6920 was a pretty decent do it all, first AR option. It wasn't the best at anything, but did alot while you figured out what you liked, didn't like and needed/ didn't need. You could make the same argument with a factory BCM as well with current Colt 6920 prices.

 

[ElPollo]

I will second others that most forged lowers are all the same. I built one a few years ago on an Anderson lower that was about the cheapest thing I could find and it’s run flawlessly with an Aero slick-side upper.

I will also recommend the Rock River Varmint trigger. It’s a non-cassette trigger that looks like a mil spec trigger. I think I got mine for $80. It’s supposed to have a 3.5# two stage pull, but I’ve never weighed it. It feels lighter to me and is quite crisp. I prefer it to the CMC 3.5# cartridge triggers that cost quite a bit more.

Finally, if you are going to SBR your lower, keep in mind that NFA regulates travel of registered firearms across state lines. It’s not impossible to deal with, but requires that you contact law enforcement and inform them at your destination before departing. My AR crosses state lines a lot as it generally rides in my truck while I am quail hunting. I ended up going with a 14.5” pinned and welded barrel to keep things compact. Honestly, I don’t know if I would bother with anything less than 16” if I were doing it again.

 

[justinspicher]

Do you have any issues with the buffer spring on the lower not mixing for all of those calibers? I've read some stuff that they won't play well together.

I use an H3 buffer with the issued KAC buffer spring. No issues.

 

[treillw]

Noveske fan here.. They are expensive and kind of fancy- but many other quality options exist that will work just as well.

I like the adjustable gas block, especially for a 5.56. But not sure why would want to turn it into a bolt gun with 300BO subs. I guess maybe if you're at the range and want to work targets without burning through ammo?

Once you built the first lower and 2nd upper, you'll likely start another build for a different application- long range, etc. It's just fun and usually how it goes. The Geissele SSA or SSA-E triggers are a good starting point, too.

A long while ago I remember looking at "my first AR" threads and a resounding theme was the Colt 6920 was a pretty decent do it all, first AR option. It wasn't the best at anything, but did alot while you figured out what you liked, didn't like and needed/ didn't need. You could make the same argument with a factory BCM as well with current Colt 6920 prices.

Noveske has caught my eye as well.

300 Blk ARs are louder than 300 blackout bolt guns because of the action cycling. My theory is by turning the gas off, it would be just as quiet as a bolt gun (if you're going for that) and you can turn a knob and have it ready for zombies. Basically saves me from spending $500 on a ruger american that I will only use for shooting subs.

 

[treillw]

Any experiences with this dude? Seem to be very nice.

Precision Firearms - Custom Competition AR-15 Uppers

Custom AR-15 Type Rifles and Uppers. Specializing in 6.5 Grendel, 6.8 SPC, 308, 260 Remington, 243, and 5.56 or 223 Wylde Chambers. We build on the AR15 Type Action and AR10 or LR308 action. We use Barrels from Lilja, Bartlein, Hart, Kreiger, and Lothar Walther. Precision Firearms is an FFL...

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