300 blk AR converted to??????

[BigBore45]

I'm not sure if you cast bullets or not. I love the 7.62x39. I run a 160 gr. That finishes at 170gr. G.C. lee hitek coated at 2068fps out of a 16" ar. It shoots sub MOA at 100 yards and should be a power house in deer sized game out to 300 yards. It also does well with heavy 220gr sub sonic pills and the standard 120-130 grain bullets.
As far as the 300 blackout doing what a x39 can. That's false when it comes to speed. Also the magazine for the x39 is a bit of hindrance if you want more than 15 rounds. I can get 15 rounds of x39 in a standard 30rnd mag and it works.
I do have x39-6.5g specific mags aswell.
.17 cents a round for x39 ammo to shoot is great. I have built 14 ars in x39 and all have held atleast 1.5" with the steel case ammo.

 

[Walkalong]

I keep going back an forth between 9mm, 6.5 Grendel and the 277 wolverine. I’m most likely going to go 9mm simply because anything I would do with a 6.5g or 277 is already covered by one of my many other guns, but a pistol caliber carbine is something I don’t currently have

Yep, for a range toy a 9MM AR is hard to beat, tons of fun, cheap to shoot, ammo can be had anywhere, low recoil, puts smiles on anyone's face who shoots it from kids to grandpas.

Sure, a 6.5 Grendel would be cool, and even useful, and a 277 Wolverine sounds cool and should be fun, but for cheap fun at the range, the 9MM AR is hard to beat. And being an AR, it can be suited up in a thousand configurations.