AR build: Suggested caliber?

[cartmanfan15]

Crap. Now I'm thinking .300 blackout might be where I'm leaning. Seeing some 16" stainless steel barrels for $200. Oh man...now I'm stoked. Already have the upper and everything chambered in 5.56.

 

[Kick]

I want to build one in .308 cal soooooooo bad but, that's a project ay down the line. I have 5-6 in line ahead of it right now...

I have never been a big fan of pistol caliber long guns. It almost defeats the purpose. You can be more accurate with it but, you still do not have the range of a "true long gun".

 

[DarkRose]

Crap. Now I'm thinking .300 blackout might be where I'm leaning. Seeing some 16" stainless steel barrels for $200. Oh man...now I'm stoked. Already have the upper and everything chambered in 5.56.

I'm looking at a blackout my a build down the road. I don't plan on shooting much (if any) subsonic, and can't seem to find any barrels over 16"... To reach it out a bit more, a 20" seems like a good length...

I like the fact it uses same bolt and mags as .223, no swapping bolt heads or enlarging ports like the .458 SOCOM, and more punch without swapping lower and all (AR-10)...

 

[mammynun]

I'm looking at a blackout my a build down the road. I don't plan on shooting much (if any) subsonic, and can't seem to find any barrels over 16"... To reach it out a bit more, a 20" seems like a good length...

I like the fact it uses same bolt and mags as .223, no swapping bolt heads or enlarging ports like the .458 SOCOM, and more punch without swapping lower and all (AR-10)...

My understanding is that factory 300BLK typically uses fast burning "pistol-ish" powder(s) and there's nothing to be gained in (FPS) by going over 16". It's been suggested on other forums that the 16" barrels exist only to satisfy the BATFE. If you reload I guess you could work up something.

I have a 300BLK for the reasons you mentioned as well as a few others. I wanted an SBR and a suppressor. 300BLK lets you have .30-30/7.62x39 ballistics (supersonic), and exceptional ballistics and sound suppression when compared to 9mm/.40S&W/.45ACP sub guns (subsonic ammo)... all accomplished by switching ammo. That's what I was looking for. Sure, there are choices that are better at one end of the scale or the other, but nothing else that I'm aware of does both as well.

 

[DarkRose]

My understanding is that factory 300BLK typically uses fast burning "pistol-ish" powder(s) and there's nothing to be gained in (FPS) by going over 16". It's been suggested on other forums that the 16" barrels exist only to satisfy the BATFE. If you reload I guess you could work up something.

I have a 300BLK for the reasons you mentioned as well as a few others. I wanted an SBR and a suppressor. 300BLK lets you have .30-30/7.62x39 ballistics (supersonic), and exceptional ballistics and sound suppression when compared to 9mm/.40S&W/.45ACP sub guns (subsonic ammo)... all accomplished by switching ammo. That's what I was looking for. Sure, there are choices that are better at one end of the scale or the other, but nothing else that I'm aware of does both as well.

Ah, well, that seems to negate any gains, unless a medium burning powder would work to "spool it up" a bit more so to speak. Was just thinking of gaining velocity and flatter trajectory, in a seemingly more economical package. The least number of components that have to change (barrel only).

 

[Ljungman]

My 2 cents would be the 6.5 Grendel. Its SAAMI rated now which means more companies are free to produce ammo, brass, bullets and the like with out the hassle of licensing fees...I.E. cheaper for YOU to buy the affore-mentioned items. also it willb e easier to get ammo to access the brass to reload. And grendel, although not as hyped as 6.8 spc, has always had one chamber specification. The 6.8 has i believe 3 different chamber specifications..too much confusion there..
Id toss for 6.5. Bigger round much better balistics and penetration than the .223/5.56

 

[ryknoll3]

I'm building .300 BLK myself. but AIM Surplus has brass-cased Wolf Gold 6.5 Grendel for $12.95/box, which is only $1 more than the cheapest 300 BLK out there (Remington UMC @ 11.99/box)

Don't know how well it works, but that's not that big a difference. You will need to invest in in different bolt though.

 

[melensdad]

The Wolf is not too bad. This is a 5 shot 200 yard target.