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Posted: 9/14/2026 10:20:45 AM EDT
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I'm troubleshooting a 10.5-inch .50 Beowulf/12.7x42 AR and am looking for actual gas-port measurements from anyone running a similar short-barreled, carbine-length gas setup. The upper originally had a Bear Creek Arsenal barrel with a pistol-length gas system. That barrel cycled, although I had feeding issues with it. I replaced it with a Hitman Industries 10.5-inch barrel with a carbine-length gas system. With the Hitman barrel, the rifle is severely short-stroking. I'm using a standard carbine spring and a 2.8 oz carbine buffer. Slow-motion video shows the carrier moving far enough rearward to reset the hammer, but not far enough to eject the fired case. Fired cases extract and eject easily when I manually cycle the action. I've swapped in another known-good BCG to rule out a carrier/gas-key issue. The gas block appears properly aligned and secure. I've also removed the handguard so I can access the gas system while troubleshooting. I measured the Hitman barrel's gas port with drill bits and a #48 (.076") is snug. For comparison, I pulled my original BCA barrel. Its port accepts a #45 (.082") and appears to be just under .086". The BCA uses pistol-length gas, though, while the Hitman uses carbine gas, so obviously it's not a direct comparison. I contacted Hitman asking what their intended gas-port diameter is but haven't received a response. Does anyone have an actual measured gas-port diameter from a 10- or 10.5-inch .50 Beowulf/12.7x42 barrel using a carbine-length gas system? I'm particularly interested in actual measurements rather than generic gas-port charts. I don't want to alter the Hitman barrel until I have a better idea of what a properly functioning comparable barrel is using. Any help or suggestions would be greatly appreciated! |
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