Complete Upper or Swap barrel and Bolt

[RhinoinTx]

I am very new to the AR scene. I have a AR in 556 and have a new 18" group by barrel and bolt in the mail. Question is do I swap them out or build a complete 6.5 Upper so I can just swap them out. If I go complete upper I need serious guidance on what to build.

[A5BLASTER]

I say build a new upper, that way after you get addicted to the grendel you will still have a full 556 upper you can sell and make back most of what it cost to build the grendel upper.

[grayfox]

Build the upper. It's not that hard just take your time. Get the upper-receiver block ("Delta Series Upper Receiver AR-15 Action Vise Block Clamp") that folds over the upper recvr and holds it all in a vice from Wheeler engineering.
I usually get an "upper assembly" that has the dust cover and fwd assist already installed, then go from there. Then you can swap uppers and pretty much have have 2 for 1 type of thing.
Aero makes a good one, so is BCM but the BCM is really tight (there's easy trick to getting the barrel fitted in.. no sweat).

[LRRPF52]

New upper. Get a made in Texas LaRue Stealth 2.0 upper/handguard combo.

https://www.larue.com/products/stealth-2-0-receiver-and-handguard/

Any decent AR15 bolt carrier and small parts will work, but I personally have had best results with BCM, PF, and LaRue.

I really like the Bootleg adjustable gas carriers, which might be something to consider with an 18" MLGS.

Set aside a good portion of your budget for optics and a quality mount.

[RhinoinTx]

Thanks,

Barrel came today so now I am ready to get started. Thanks for the advice.

[RhinoinTx]

New upper. Get a made in Texas LaRue Stealth 2.0 upper/handguard combo.

https://www.larue.com/products/stealth-2-0-receiver-and-handguard/

Any decent AR15 bolt carrier and small parts will work, but I personally have had best results with BCM, PF, and LaRue.

I really like the Bootleg adjustable gas carriers, which might be something to consider with an 18" MLGS.

Set aside a good portion of your budget for optics and a quality mount.

I have a spikes lower that I will be putting the new build on. I really like the Larue product you posted but really want a FDE handguard. I want to suppress it so I am thinking a 15" handguard and was told to get a rifle length gas system. Thoughts?

[Swampfox]

Agree complete upper. Rhino check out https://www.armorally.com. Aero Complete upper receiver with hand guard. Spikes tactical gas tube, raptor LT charging handle, superlative arms adjustable gas block, and RTB low mass carrier group.

[biodsl]

Don't disassemble the 5.56. I think it's wise to keep one around just in case of the end of the world as we know it. Build a complete Grendel upper.

[Klem]

Build a new upper. Keep the 5.56 upper.

Are you wanting a reflex or muzzle-forward suppressor? Reason I ask is because you don't need 15" of handguard which then limits you to a muzzle-forward can (unless that's what you want). Look at where you naturally hold the rifle, whether it be a vertical grip or hand on the handguard. I put it to you that anything forward of your hand needs to have a good reason to be there. For me, 11" or 12" is as long as I will ever need, maybe even less. That's also for bipod and barricade resting. Let's face it, the likelihood you you will never need that extra 15" of sight radius if you have a scope on the gun, and it happens to break, in the field, and you can't withdraw, and you can remove the scope at the time, for those BUIS, is about never. If however you are going to build and use that AR15 without a scope, which would be unusual in 2018, then by all means.

Reflex cans typically need about 4" of barrel clear back from the thread. Unless you use a wide-body handguard that encompasses the can like a Seekins MCSR (with 1.8" inside clearance).

If it's a muzzle-forward suppressor then your handguard can be as long as you like, but I still think anything further than your hand is of limited value.

[RhinoinTx]

All great info. Still need to do my research on suppressors to answer that question.
So I have 18” monster barrel.
Thinking Areo upper/handguard in 12”.
Questions is about gas system if I suppress it. Mid length or rifle length? Superlative adjustable seem to be most popular considering they are sold out most places.