AR 223 change to 300 blackout?

[rschu53]

I'm an old dog trying to learn new tricks. I have an AR in .223 and wanted info on converting to another caliber. What parts do I need to replace, what still fits. I just threw 300 blackout here, but what other calibers are out rhere I can use?

[Deedle]

For 300 BLK just get an upper:

[Flintlock Tom]

For 300 Blackout you just need to replace the barrel and muzzle brake. You can use the .223 BCG and magazines.
7.62x39 is also popular; just replace the magazine, bolt and barrel.
Most other calibers: magazine bolt and barrel.

[Ora Serrata]

300 black out is really easy. Just get a barrelled upper and you're good to go. It uses the same bcg as 223,and the same magazines. I've got a couple that I just swap out on the same lowers as my .223's.

PSA has them for around $230 without bcg. Shipped directly to your door.

[Flintlock Tom]

A replacement barrel is only 42 bucks, plus shipping...

300 Blackout barrel

[alpha_romeo_XV]

If just swapping barrel just be sure the feed ramp on your upper is compatible with the feed ramp on the new barrel extension. AR15barrels.com has a good explaination with photos on his website.
My 7.62x39 upper has required some dremeling of the feedramp and magazine front lip. Relatively easy DIY for me.

[FlyingShooter]

While fun to put holes in paper up close, I think you will be disappointed in 300 Blackout performance overall out of barrels 16” & longer. The caliber shines in a pistol or SBR’s.

[edgerly779]

I have a 300 aac blackout 16" upper I am selling . Use you bcg and charging handle and mags. I have 2 and don't need this one.

[DazedandConfuzed]

Certainly 300 BO is the most cost effective caliber change, but there are many more, i.e. 22LR, 6.5 Grendel, 6.8 SPC, 5.7X28, 7.62X39, 458 SOCOM, 50 Beowulf. I may have left something out, but you get the idea.

[crufflers]

300 BLK has similar energy to .223 at 200 and 300 yards if you use a 110 grain bullet.

[toiletfighter]

300 BLK has similar energy to .223 at 200 and 300 yards if you use a 110 grain bullet.

[crufflers]

Yeah, Honady's website is one place you can look at different loadings they sell at different distances, etc...

https://www.hornady.com/ammunition/rifle/300-blackout-110-gr-gmx-full-boar#!/

they use 16" test barrels for 300 BLK.

If you compare M193 to 110 grain 300 BLK it looks pretty good to me out of 16" barrels.

https://www.ar15.com/forums/ar-15/300BLK_Ballistics_vs_Barrel_length/121-709725/

There's a caption on the chart in this thread that says it is "better in shorter barrels than 5.56" but the chart shows it is better than 5.56 in longer barrels too.

[Lightstrider]

So was 300bo developed mainly for extra stopping power and better ballistics for the military or....?

I could google but would rather have story time

[Flintlock Tom]

Someone accidentally fired a .223 in a .308 barrel and blew out the mouth of the case. Then someone said "Hey! Let's stick a bullet in that."

[Tommy Gun]

I thought 300 blk was for suppressed fire. It's also known as whisper for the aforementioned reason. Guess it's pretty quiet and the American answer to the 7.62 x 39mm??