Almost a year ago I commissioned a 300/221 Fireball AR15 barrel to be made by Lothar Walther. The barrel was designed to have the following specifications:
- 16 inch barrel
- Pistol length gas system
- 1:8 twist rate
I was later informed by Lothar Walther that they would be changing over the production of all 300/221 Fireball barrels to the 300 AAC Blackout chambering, and that mine would so too be changed. After a little research though, I discovered that the pistol length gas position is less than optimal with the 300 BLK cartridge, and that a carbine length gas system is preferred. Since the barrel has already been contoured for use with the pistol length gas system, both Lothar Walther and myself are unsure of what the best diameter of the gas port should be in the pistol position. I will be using the rifle in both supersonic and subsonic capacities equally. Also I would like it to cycle reliably with sub/supersonic rounds whilst firing without a suppressor, and yet not be too over-gassed when firing suppressed supersonics.
Does anybody with experience have any idea what the gas port diameter on the barrel should be if the barrel is set up for a pistol length gas system? Any help would be more than appreciated. I'm kinda at my wits end with this project.
- 16 inch barrel
- Pistol length gas system
- 1:8 twist rate
I was later informed by Lothar Walther that they would be changing over the production of all 300/221 Fireball barrels to the 300 AAC Blackout chambering, and that mine would so too be changed. After a little research though, I discovered that the pistol length gas position is less than optimal with the 300 BLK cartridge, and that a carbine length gas system is preferred. Since the barrel has already been contoured for use with the pistol length gas system, both Lothar Walther and myself are unsure of what the best diameter of the gas port should be in the pistol position. I will be using the rifle in both supersonic and subsonic capacities equally. Also I would like it to cycle reliably with sub/supersonic rounds whilst firing without a suppressor, and yet not be too over-gassed when firing suppressed supersonics.
Does anybody with experience have any idea what the gas port diameter on the barrel should be if the barrel is set up for a pistol length gas system? Any help would be more than appreciated. I'm kinda at my wits end with this project.
