That gas block works fine as long as it is aligned. The ammo is your culprit, but to make the gun run cheap ammo or mil spec, you would be advised to read my post above on gas port size in the barrel.

This really has nothing to do with the chrono speed of the bullet, but how fast the burn rate of the powder is and the associated pressure curves. The guns come gassed for slower burning, US made hunting ammo as used commonly in a 24" or so barrel to achieve full push!

Look at your ejection pattern and last round lock back as well.

The specific sizes I mentioned at .073- .075 do require specific number or letter drills in most cases, but they are cheap.

Enlarging the hole is easy enough with a quality sharp drill, just install a stop so you do not disturb the other side of the barrel bore. The metal is soft enough to drill easily without breaking a bit. If you do, you did not heed advise given by me and you likely have two thumbs in each hand, get help!