Yeah. I’m not playing pistol. I like 16 & 18 inch barrels.
You can certainly build whatever you prefer, but simply in terms of accuracy, a 300bo gets its maximum power burn in 9-10" of barrel. There's no real advantage of a longer barrel than that. So take a 9" barrel and slap a suppressor on it, and your overall length is still in the 16" range, WITH the suppressor. Slap a 12-15" handguard on there and you're ready to rock and roll. The only downside is you are still technically shooting a pistol, so it has to have a pistol lower, with a "brace", but hell now they got "braces" that are 6-position just like a regular stock. That whole thing is a joke.
There’s nothing wrong with a pistol length barrel for 300blk. In fact it is preferred by most to wring what “benefits” there are in that particular cartridge out of a weapon. But the idea that barrel length effects accuracy is a myth. It does not. There are 9” barrels that will shoot 3/4” groups and others that will shoot 3” groups with the same ammo. Sight radius may come into play if the user is relying on iron sights but that can be mitigated with a reflexed handguard (assuming you are only running it with a can). Of course that can is going to add another $600 or so and a years wait to your build. It is true that, in general, all of the powder is burned in the first 9-10” but you’ll gain about 25fps velocity per inch of barrel out to about 18” and then 5-10fps out to around 30” if I recall correctly.
If you intend to hunt with subs and a can, a 7-9” pistol is all you’ll ever need. If you plan to use supers most of the time then 9” is also fine but going out to 16” will extend your effective range with premium bullets. The difference between 150 yards and 250 yards is moot if, like many, you are looking at the 300blk for very short range hunting. Until you’ve found yourself with an opportunity at 225 and you just don’t have as much ‘ooomph’ as you need with what you are carrying.
