What's the optimum barrel length for a 300 blackout pistol?

Who makes a good 300 barrel at a good price?

Twist rate?

Go 9"-12" for the barrel. If you plan on shooting 220 gr. and heavier, go with a 1:7 twist rate for sure.

Aeroprecision offers several lengths. I like the 8.5 as I like to run suppressed.  It is also very lightweight and maneuverable  unsuppressed.

Thanks, I do plan to suppress it down the road, initially unsuppressed
What is the standard grain on commercial ammo?

CMMG does a nice 8".

Commercial made ammo can run projectile masses from 110gr to 240gr.  The 110gr Barnes TAC-TX (black-tipped) are designed specifically for the 300 blackout and are very effective at causing destruction.  I've handloaded 125gr Speer, Sierra; 194gr, 210 and 220 gr combos of varying manufacturers.  The subsonic stuff (typically 194gr and heavier) works very well (unbelievably quiet)  if you can suppress.

Depending on powder, etc.; the optimal length is said to be around 9 but a lot of builders are having luck with shorter barrels.  I've got one under construction, going with 9".  Currently have a factory built 16" 300blk Carbine.

EDIT:  +1 on the twist rate statements already made.  My 16" has a 1x7.  That's really only necessary for the 220+ projectiles but it works just fine with the full range of projectiles.

ok so keep it around 9" and 1/7 is the better rate to run overall, my 556 ar's I run 1/8

i am assuming the short "pistol length" gas system is the one to use since what i see for sale is mostly the short gas system

on barrel weight, should i look for heavy medium or light? is there alot of muzzle rise where the heavier barrel is better or go for a light stainless barrel?

Pistol gas is pretty much mandatory for 300BLK because the pressure curve drops off a lot faster than 5.56. For subs to function well, the gas port needs to be close to .125, which is close to the ID of a standard gas tube. Making the port larger won't help cycling because gas flow will be limited by gas tube diameter.

Options on ammo

I will second the Aero Precision . Everything I've bought from them has been excellent.

For a 9" you would have a pistol length gas tube. I like light weight profile barrels for pistols myself. Recoil is not an issue.

I also suggest a linear comp or some other comp that directs muzzle blast down range.

thanks for all the replies, like i said i am going to end up doing a form1 and building a can for this so should i still do a linear comp or is it tolerable with one of those aac t11 suppressor adapter fh i keep seeing in the ee cheap

also for a ff rail are there pistol lentgh out there or should i buy a long one and cut it down to what i want like on my sbr?

A flash hider isn't going to help with redirecting the blast forward. It's about $50 for a linear comp (ie BRT, Kineti-tech, etc)

Use a car length rail instead of a pistol...  I have a 7.5" barrel and the car length is good. I used a mid length rail for a 10.5" barrel.

THANKS

http://www.kakindustry.com/kak-300-blackout-9-inch-pistol-stainless-barrel-5r7 fantastic barrel!

is a stainless lighter then the steel barrel at this short? think a steel one i looked at was 9" and 21 oz, the kak one does not list a weight for stainless

Barrel profile (ultralight, HBAR, etc.) makes far more difference than the type of steel.

What is your price range on barrels that you are seeking.  

They seem to run anywhere between $90 and $450.  Lower end of the spectrum will be CMV, no chrome bore/phostate finish finishes.  Higher end you are looking at Noveske SS barrels.

You have material options from 4140CMV to 4150CMV to 416SS.

You have finish options from chrome lining, no chrome lining/bare bore, melonited/QPQ, phosphate finishes, SS finish etc.

I narrowed down my pick to Aero Precision because of a couple of reasons:
Sub $200 barrel (AP has their 8.5" for sale for $189 with free shipping right now.  I waited 3+months for the 8.5"s to come back into stock.  I just saw they came back into stock within the past 2 weeks or so.)
1:7 twist
Melonited barrel inside and out
Dimpled for LP gas block
8.5" length (Wanted 9", but there are not many options out there for 9" barrels.  Most are in the 8-8.5" range.)

Many other barrels offer similar specs/prices like Ballistic Advantage (I actually liked that BA had a 9" 300 BO barrel), CMMG etc.  The 2 deciding factors for me was that I had an Aero Precision LP gas block and figured I would just match it.  The biggest factor is that AP labels their products to be HP and MPI tested while others did not.  Barrels I've seen around this price point seem to not advertise their barrel being tested or not. So the other manufacturers/distributors may indeed HP/MPI test their barrels, but I have no way of knowing.

around that $200 mark is where i want to be, i run ss barrels on my precision ar and my sbr figured i would do the same here but ss barrels are stupid hi for 300 blk and every used one i see short like 8-9" guys want to sell the whole upper so...

i also want to keep it lite

7.5" 300 AAC BLACKOUT 1x7 HBAR STAINLESS STEEL BARREL for $129.99 @ Mas defence . thats what im going with next  

Also look at the Palmetto State Armory 10.5" upper - the barrel is a heavy profile and manufactured by FN. I own two .300 Blackout pistols - one with the Palmetto upper and one with a Spikes Tactical upper which, I believe, has a Lothar barrel. The Palmetto is easily as accutate and reliable with both supers and subs with a Spikes H2 buffer. The only difference - the Spikes was $1K; the Palmetto was $399 (including the BCG).

mas defense barrels look good i may grab a stainless from them    just need to decide 7.5" or 8.5"

any pice of these sizes on a 7" ff rail?  and does that 1 inch make a huge difference on accuracy?

I have an 8.5" that I found to be surprisingly accurate, it's  Radical Firearms.

ok lets look at length this way, i am going to suppress this after i do the form 1 which length barrel is better for that?

Surplus Ammo has BHW stainless, 10" 300 BO barrels for $228 and they give you a stripped SAA upper.  The barrels have a black coating, not sure if it is QPC or not. That brings the barrel price under $200 when you consider tge free upper.

A longer barrel is easier on the suppressor baffles. Doubt if 1" is going to make a world of difference though...

double tap

Thanks all,  ended up with 7.5" ss h bar 1/7 for 129 shipped, and a 10 oz 7" ff quad for 35 shipped, already had the upper

Thanks again for all the info