cst Wrote:I hear what ur saying..do u feel that clamping may be more retentive than setscrew? I am trying to build a rock solid tactical rig..thats why I was gonna pin it
Yes.
Clamping is the latest innovation in gas block retention. Originally it was pinning and then set-screw. There seems to be general agreement that set-screws are not as solid as pinning and have a tendency to come loose, especially if the gun is worked hard. This is unacceptable for those who trust their lives to the gun.
There does not seem to be the same doubt about clamping. When you think about it set-screw designs 'pull' the top of the block down to create the bind. When tensioned, the only parts of the block making friction contact with the barrel is the inside top and the tips of the screws at the bottom. This is less efficient than a block designed to flex as it is clamped. Clamping has more surface area contact with the barrel for a better seal and more friction. This probably has a bearing on keeping the clamping screws from coming loose. But, they still use screws to clamp and any screw can come loose.
There are some low profile clamping designs out there. Daniel Defense and VLTOR are two low profile designs of clamping blocks.