So I finally bought a stripped AR lower and decided to build an AR. I've never owned an AR of any kind but always wanted one. Anyways what I'm curious about is what caliber to go with. For simplicity sake I'm looking at either 5.56 or .300 blackout since they both use the same parts except the barrel. Right? So what's the pluses and minuses of these two cartridges?
Any input is appreciated. Thanks all
Yes, you're correct, the only thing different is the barrel... Same bolt, same mags, same everything else.
Pros and cons...
Pro's: 5.56 is easy to find, cheap, fast, low recoil and is a great varmint rifle and plinking round.
Con's: 5.56 is not very powerful and because of this, it is not really good for hunting anything much larger than a coyote. It will kill, but not as efficiently as something larger with a bigger bullet. Even with a suppressor, the supersonic velocities of the 5.56 will still make it much louder than the .300 BLK.
Pro's: .300 BLK has a larger and heavier bullet. It's purposely designed for shooting sub-sonic rounds suppressed and to be VERY quiet. Ammo is getting much more common these days and there's lots of good factory options for both subsonic and supersonic ammo. Also, if you reload, it just uses any standard .308 caliber bullet, and you can make your own .300 BLK brass from cut-down and re-formed 5.56 cases (which is what I do).
Con's: While ammo prices and options have improved, .300 BLK ammo is still ridiculously expensive for what it is, compared to the 5.56. So, unless you have a progressive press and are loading your own, it can be very expensive to shoot. Luckily, I work for an ammo plant and one of our calibers that we make is .300 BLK, so I get 220gr subs very cheap, so I buy a bag about once a month to stock up, since I don't have a progressive press yet.
Overall, to start out in the AR game, I too, recommend the 5.56. Make sure you get a barrel that's actually chambered for 5.56 NATO and not .223 Rem. And make sure you get a 1:7 twist, this way, if you plan on hunting hogs and deer, you can stabilize the heavier 75-80 grain bullets.
