Didn't want to hijack the other thread, so I'm starting my own. For those in the know, what length barrel would you get for a 300blk pistol and why? I am not interested in other calibers at this point. It will be suppressed part of the time, and I will fire subs and supers depending on the situation.

Currently, I'm not suppressing my 10.5" barrel and no plan to. I like the 10.5" length (unsuppressed) and for an AR pistol, it is very compact. When shooting it sometimes, I catch myself with my forward hand right on the edge of the forend. I don't want my hand having a chance going forward of the end, so I think 10.5" is as short as I would go unsuppressed. If suppressing, it changes things up. A 7" or 8" would work well, even 10.5", and you won't have to worry about your hand going forward of the barrel. I forget the FPS loss per inch, but at about 7" or 8" and going shorter, the FPS fall off gets more.

But, there are a lot of Super Short Barrels (SSB) out there. There's some 5" one's I've seen now. I'm also loading 300 blk out ammo specific to the SSB pistols. With the 5" barrels, the traditional ammo used for 16" barrels becomes VERY dirty in the 5" due to the incomplete burn of powder. I've changed it up to allow a 99.7% burn of powder with the SSB ammo. Going that short, you can still get a good load, better velocity, and much cleaner round. There's good options with whatever length you want.

I personally run a 8” 300BLK barrel on my SBR. I’ve only shot pigs with it out to 150 yards. Have smoked them all so I have no doubt it would be very effective on 2 legged critters as well. I run mine suppressed 100% of the time. I don’t have the problem chad talked about. For one I have TRex arms and 2 I run a vertical foreword grip so that is where my hand rests. A hand stop, which is legal to put on a pistol, would alleviate that issue.

That said I’ve been wanting to build a super short barreled PDW in 300BLK. Glad Chad is making loads for them. I’m wanting to go 5.5” barrel and build a complete SLR PDW SBR. If I ever sell my Seekins that will be what I’m doing.

I was thinking 8.5. I have been watching the PSA website, and they have 10.5's and 7.5's coming in and out of stock, but I haven't seen an 8.5 in a while.

I like the balance of the 10.5" guns, so that's how mine are set-up (.22, 9mm, 10mm, 5.56, .300, 7.62x39)

Really depends on what you want to do. I think about 7in is as short as I would go. If you are only subsonic, barrel length doesn’t matter. Also if you really want subsonic performance faster twist can help, think some people make 1 in 5 twist.

So what are the best quality 300BLK barrels out there? I'm a big AR15 Performance fan but Harrison doesn't make any in the BLK. I would want a barrel commensurate to the ARP.