I noticed that a lot of rifle and carbine 300 AAC barrels have pistol length gas systems, does this mean they run better with that size gas system? Thanks for setting me straight on this.

Steve............

300 Blackout has much less powder, and a much larger bore diameter so the gas volume is much higher. As a result, pressure drops very rapidly as the bullet goes down the barrel, much faster than in 223/5.56. Consequently, the gas port needs to be closer to the chamber to get enough total energy to cycle the action.

There are 16" barrels with carbine gas system lengths in 300Blk, but some say they are marginal or unreliable with lower-pressure ammo (mostly subsonics).

So does an adjustable gas block closer to the chamber fix any cycling issues depending on if you're firing suppressed or unsuppressed?

I kind of feel like all the science and mechanics kinks should have been worked out of this by now. No?

That's what I was thinking but wasn't sure, it seems that if I got one of the 300 AAC barrels with a carbine length gas systems I would be ok as I don't plan on shooting suppressed or subsonic ammo, I hope, LOL.

Steve..........

This is the route I went. I looked at the various methods claiming to correct issues. I wanted to be able to shoot both subs and supers so I went with an adjustable gas block from the start. And it works! 

wingsnthings

Is your gas system a pistol length system?

Steve..........

Steve, It will depend on what your are planning to shoot really.  I chose a carbine length gas system because I will never shoot my .300 suppressed or use sub sonics.  It is a dedicated hunting rifle and whether or not the HPA passes, FL does not allow using a suppressor for hunting.  I agree with what has been said above about the science behind pistol vs carbine systems. IIRC an adjustable gas block wont do you any good on a carbine system, you may actually have to open up the gas ports some if you plan to use a suppressor or shoot subsonic.  It would be all the way open anyway to get the system to cycle.  You may want to use one on a pistol length system to have it cycle properly with different loads and suppressor use.

I did some research before buying parts for my .300 build so I would suggest you do the same.  I may not be providing accurate info because its been a while since I looked around.  I do know my carbine system has not hiccupped with supers so I am happy with it.

Good luck from another Steve!

I built a 300 with the sole purpose of hunting and shooting super sonics. 16" barrel with carbine gas. Works just fine.

My 16 inch AAC upper with carbine gas system cycles subs and supers without a hitch.

IIRC being able to shoot subs and supers interchangeably without adjustment was one of the design goals of the .300 Blk cartridge.

I don't know about other brands but the AAC uppers do, and I think this is due to the pistol length gas systems.

Not trying to hijack the thread but you guys that are hunting with the 300blk what are you hunting and what kind of effective ranges are you seeing? Thanks.