My first build in the planning/buying stage- Pistol AR Daniel Defense in 300 Blackout

[Blockhead]

I don't have any drool worthy pics yet, but I've started down the path to doing my first AR build. I'm on the list for a Shadow Ops lower and have arranged to purchase a complete Daniel Defense upper in 300 Blackout with a 10.3 barrel. My mid-term plan is to use build the rifle in pistol configuration and eventually put together paperwork to make it a registered SBR after I make sure the lower will work well with the upper. The really long term plan is to get a suppressor for it eventually too. I wanted another AR in a heavier caliber and liked the interchangeability of parts and mags between the 5.56 and 300 (especially since we will soon be restricted on buying mags).

Does anyone have any tips or hints for what seems to me to be an ambitious project for a newb?

[Hoser]

Brass, dies and bullets should be on your shopping list.

[Blockhead]

Brass, dies and bullets should be on your shopping list.

All good points. I've never been a reloader, but trying to feed this rifle will likely provide some strong motivation.

[Dave]

Brass, dies and bullets should be on your shopping list.
From what I have read here and a few other places, if you get into either .300 or 6.8 uppers you will want to reload as prices and availability of ammo can be dicey at best. I am wanting to get a rifle length .300 for hunting purposes to swap out with a 20" 5.56 upper on my Shadow Ops lower. This way I can swap the uppers out on my hog hunts in TX, .300 for the pigs and 5.56 for varmints and coyotes and use the same mags.

[Rocket88]

I have been making 300 AAC cases from .223/5.56 for some time now. A full set of 300 AAC dies is all you need. I cut a .223/5.56 right at the wide shoulder on the neck of the case, run it through the 300 AAC FLS/DeCap die, then trim to length (de-burr in and out), and run it through the die once more. The head stamp will be wrong of course - but if that matters, you might need another hobby.

Proper projectiles are not hard to come by- but the powders can be a challenge. Pay attention to the OAL of the projectile- you will want to buy projectiles that are "optimized" for 300 AAC (longer than a typical .308" projectile of the same mass).

Assembling the rifle is no more challenging than a .223/5.56 as the only difference is the BBL. www.midwayusa.com has a good tutorial on building an AR.