Got one of my blocks and still having cycling issues? Chances are your gas port is too small. This is done by a lot of barrel manufacturers to ensure a reasonable level of reliability with a standardized build setup without causing an over-gassed condition. Anything exotic outside of that standardized build, however, causes problems with reliability.
The solution to this is to blow out your gas port to the max possible size (0.125") and then use an adjustable gas block to "choke the gashole" to an acceptable level for reliable function. To do this safely and effectively, one uses a 1/8" drill bit and inserts a dowel rod down the bore to back the drill bit from marring the bore. Drill out the port, assemble everything together and get back to shooting.
Included in this kit is the following:
-1x 1/4" dowel rod, 12" long (for .30 builds)
-1x 3/16" dowel rod, 12" long (for 5.56 builds)
-1/8" drill bit.