View Full Version : 1st and 2nd ar builds what caliber would you suggest

10-17-2009, 8:29 PM
so im doing or tiring to do 2 ar builds right now as much as money will let me anyway and im wondering what caliber i should build the second first is gonna be 5.56 and for the second im thinkin 7.62x39 or 9mm since i already have guns in those calibers and thinkin it would be good to minimize the diffrent types of bullets i need because of this restriction thing but i have also been thinkin about doin it in 5.7....whats your thoughts??

10-17-2009, 8:44 PM
What are you going to do with them? If anything long-range, get a 6.5 Grendel

10-17-2009, 9:22 PM
will that fit on a reg mulit cal reciver?

10-17-2009, 9:24 PM
will that fit on a reg mulit cal reciver?


10-17-2009, 9:27 PM
My first build was a KISS 5.56, I want my second build to be a tactical 5.56 carbine with rails, light, and a red dot. I stay stick with the 5.56, IMHO 7.62x39 is for AKs and SKSs.

10-17-2009, 9:31 PM
Here are my suggestions:
1) Carbine in 5.56. Red dots or iron sights. Gas piston if you like that kind of thing.
2) SPR rifle (something more precise w/ a longer barrel) in 5.56. Scoped.
3) AR in 22LR for practice or plinking. Or one of the new beltfed uppers from Lakeside Machine.
4) AR build in a pistol caliber. I chose 7.62x25.


10-17-2009, 10:07 PM
Hey don't forget 6.8SPC. One of the better intermediate rounds available for AR15 platform.

Purple K
10-17-2009, 10:14 PM
My second was a Stag in 6.8 SPC. I've had no regrets.

10-17-2009, 11:09 PM
1) 5.56

2) 6.5 Grendel.

10-18-2009, 9:00 AM
Anyone know how remington's new 30 AR cartridge compares to 6.5 grendel? Supposedly 30 AR is between 7.62x39 and 7.62x51. Its a fat cartridge so it can only fit as a single stack in an AR type mag.

It probably wouldn't be suited for a "tactical" application, but might work well in a precision or DM role.

10-18-2009, 11:56 AM
The .300 whisper (aka 300/221 or .300 Fireball) will do a better job than the 30 RAR for most purposes. First of all, since the .300 Fireball cartridge can be (and should be, IMHO) made from .223 brass, it's a double stacker and will work in unmodified AR magazines. Even more interestingly, .300 whisper has two domains and is almost a two-fer cartridge.

Supersonic: with lightweight bullets (up to about 170 grain), it has muzzle energies and velocities that parallel the 30-30 (which makes it slower than 30 RAR). Using 30-30 soft-points and hollowpoints ensures effective expansion, though many report excellent hunting results with .308 bullets as well.

Subsonic: with heavyweight bullets (from 170 up to 250 grain), the 300 whisper can be dialed back into a very reliable subsonic shooter with equivalent muzzle energies to the .45 ACP but much better ballistics from the long high-BC bullets. If you ever move to a free state, this can be very effectively suppressed (the origin of the name "whisper").

In order to get reliable functioning with both supersonic and subsonic ammo, you need to put the gas port in the pistol position and use an adjustable gas block (wide open for subsonic, reduced for supersonic). If you put the gas port in the carbine position (this is where M1S puts theirs) you may have some difficulty getting subsonics to reliably work the action.

10-18-2009, 12:03 PM