Getting a 5.56 to just be a training/300 blackout supplier, worth it?

[Musicman1eanda]

I want to get my first AR, but I'm essentially only interested in the 300 blackout for defense (especially with great hearing safe suppression capability).

That said, should I even bother to get a 5.56 upper essentially just for training and the collection of casings for reforming into 300BC? If I got a 5.56 upper, I think I would want it to be the same length or similar in length to my blackout upper (for training consistency).


Can you even legally put a standard 5.56 upper (16in +) on a pistol lower? I would think that would result in some issues? Would you have to have an entirely separate buffer tube/buffer as well for when shooting the longer barrel? How easy is it to change buffer assemblies back and forth?



Maybe I should just jump into hand loading 300 BC. I don't know how much cheaper that would be if I even had to buy most of my brass.



This AR world is vast and confusing to a strict CCWer with two handguns lol.

[esh21167]

Until you put a stock on the lower, it will be a pistol, regardless of barrel length.

Buffers are easy to change. Same pistol tube.

Barrel length is a consideration. Full powder burn for 300 BO comes from a 9" barrel, 5.56 is 20", but the loss of velocity is minimal (around 100 FPS or so) from a 16" barrel.

Here's link with some velocity/barrel length comparisons. https://www.ar15.com/forums/ar-15/-/118-509733/?page=1

If you're stuck on the ammo cost, maybe consider this: a 16" 5.56 upper and a 8.5-9" 300 upper. If you're going suppressed with the 300, perhaps the suppressor length/weight will make it feel/handle similar to the longer 5.56 barrel.

Of course there's the initial cost of both uppers, and if you aren't reloading now, there's the initial cost of that equipment to consider. Will you recover that? And if you use your spent 5.56 casings, you have to figure how much you use for each caliber.

I wouldn't personally get a 5.56 upper for the reasons you're considering. If set on suppressed 300 BO, just go that route. Not saying a 5.56 upper is bad, just that there are different reasons to choose it.

And just to muddy the water some more, I'm just learning about 9x39, which is a kind of a Russian take on 300 BO. Don't know pricing for AR uppers, but I've read steel case ammo should be like .20/round. I believe it's a 270ish gr projectile with more energy than 300 BO.

[Hodgie]

This is pretty much a duplicate thread to you other one.

http://forum.pafoa.org/showthread.php?t=343956

[DukeConnor]

300 blackout brass is pretty cheap now. if you want to reform 5.56 just take a shovel and bucket to your nearest gun range and shovel it up.

[Yellowfin]

You'll find plenty of reasons to have 5.56 around too.