Ian
Notorious member
Got an M1A....with a scope. CASM makes the only scope mount worth having for the platform and I have a nice ffp scope on it along with a suppressor-mount muzzle brake and a Schuster adjustable gas plug. Magnificent weapon and it loves cast bullets but the whole package is nearly five feet long and weighs 13 pounds.
The Superlative Arms gas block would not vent sufficiently even when full-open with the 4320 load, but it was a lot better than nothing. When installing it I discovered that it has a dual function and will also restrict flow (nowhere did I see this in the ad hype and it doesn't come with instructions), so I worked it up from the fully-closed direction and got it working well at 23% open.
While screwing around with the gas block I was also collecting chronograph data and halfazz shooting another group. Ten shots stayed inside 1-5/8", not bad for zero load development. Predicted velocity was 2187 and actual was 2145 for a difference of 2%, not bad for throwing powder-coated bullets into the mix and and shooting the loads in a rifle with a big gas leak in the side of the barrel and a big muffler on the muzzle. The pc and gas port robs a little velocity and the can adds some back.
The Superlative Arms gas block would not vent sufficiently even when full-open with the 4320 load, but it was a lot better than nothing. When installing it I discovered that it has a dual function and will also restrict flow (nowhere did I see this in the ad hype and it doesn't come with instructions), so I worked it up from the fully-closed direction and got it working well at 23% open.
While screwing around with the gas block I was also collecting chronograph data and halfazz shooting another group. Ten shots stayed inside 1-5/8", not bad for zero load development. Predicted velocity was 2187 and actual was 2145 for a difference of 2%, not bad for throwing powder-coated bullets into the mix and and shooting the loads in a rifle with a big gas leak in the side of the barrel and a big muffler on the muzzle. The pc and gas port robs a little velocity and the can adds some back.