300 black out

[Throttle_monkey1]

Hey guys,

I just picked up an AR on impulse after getting out of the AR game. It’s in 300 black out. I know nothing of this round. Should I just re-barrel to 5.56? What weights of bullets do you guys normally shoot? Velocities?

Can I use 5.56 brass to make 300 brass? Powders? Average cost to reload? For a range toy what advantages are there to keeping it as is vs re-barrelling to 5.56

 

[nic404]

I'm new to 300 blackout but I shoot subsonic cast 220 powdercoated loads for something in the realm of 10-12 cents with a bit of labour on my end by trimming once fired 223 and casting my own projectiles. For a range toy considering I shoot mostly indoors its cheaper than 223.

Making 223 brass is pretty easy with a chop saw at the 223 neck, followed by sizing with a 300 blackout die and then cleaning it up after the trimming.

 

[CHEMMY]

300 blk is a superior round to the 5.56.

 

[mikeelliot]

Love the impulse anti gun control 300BLK
I have one too

 

[Juster]

As a range toy there isn't much advantage, except that 300 is more suitable for shorter barrels.

 

[Bartok5]

As a range toy there isn't much advantage, except that 300 is more suitable for shorter barrels.

This is they key advantage of .300 Blk - full powder burn in a 9" barrel (optimal cartridge barrel length) due to the use of fast-burning pistol powders. This means that you can easily run a 7.5" barrel on a pistol gas system without the excessive muzzle flash and blast that you get with 5.56mm.

Then there is the fact that you are launching .30 cal pills downrange as opposed to .22 cal rounds, the latter which whistle right through a target unless you happen to strike major bone. Not so much a problem with .30 cal bullets in the ~140 gr range. Whereas the effective velocity of 5.56mm is limited to ~200m out of a short-barrelled AR, The .300 Blk retains effective velocity out to ~400m, fired from an AR envelope with no increased recoil or muzzle flash/blast. All other factors being equal, bigger bullets = better results...

 

[BillD]

I have a 10.5" 300blk AR I put together last year - for ammo I got lucky with a vendor clearing out stock and bought a bunch. But I also reloaded my own using cut down .223, H110 for powder (already had a bunch of it for magnum pistol loads), and whatever light (been shooting light supersonic only so far) .308 bullets were available cheap.

P.S. as an option for ya, it's probably not much more expensive just to pick up a cheap complete 5.56/.223 upper off the EE as to rebarrel your existing 300blk upper.

 

[greentips]

As a range toy there isn't much advantage, except that 300 is more suitable for shorter barrels.

As a range toy 300 blk out doesn't do anything a 5.56 can't do and it is more expensive. It is basically shooting a 7.62X39 designed for an AR and the trajectory is like a rainbow out of a short barrel.

As a PDW, 300 blk has a lot to offer.

 

[rifleman338]

300 blk is a superior round to the 5.56.

Superior for what? Just asking as aren't these both just for punching paper or ringing steel?

 

[Candocad]

If you do not already, reloading will be a must unless you are economic with the rounds / big disposable income.

If you reload it can be reasonably economic, but never cheap unfortunately. I find the optimum bullets are always pricey. Super calibre to shoot, if only they legalized moderators now.

Candocad.

 

[Twan]

Superior for what? Just asking as aren't these both just for punching paper or ringing steel?

Like greentips said above - realistically, for the range is doesn't offer any real advantage. Given that it was designed to be shot out of short barrels - 7-9" in length, it will have minimal flash as all (most) of the powder will be consumed. The aforementioned also lends it's self well to being suppressed, and equally as important, there are various loads available in both subsonic and supersonic - often the PDWs designed for it will also reliably function with both sub and supersonic loads.

 

[Throttle_monkey1]

Thanks for all the input guys! Lol still don’t know what to do

 

[unstableryan]

How long is the barrel in your upper? If it was under 12” I’d keep it, if it was over, I’d trade it for a .223.

 

[cwtracey]

Dude, just pick up a 5.56 upper off here. You're lower and mags don't change at all. Then you got best of both worlds. I'm running a 300 Blackout with a 7.5" barrel and it's a lot of fun. I'm starting to reload for it now that I have a bunch of 300 blackout brass (got a bunch of factory loads on sale locally). It's almost apples to apples for reloading cost between doing 300 and 5.56. I guess it comes down to if you want to limit the number of calibers you are buy/reloading for.