Re: Advice? Surefire FA762K or Gemtech Quicksand?
I have both systems. I'm currently using both an HVT and Surefire 7.62 and .338 cans, plus I have the first Sandstorm (threadmount Quicksand).
The Sandstorm is the same as the Quicksand, the Quicksand just has the HVT mount.
I've used the HVT on several different rifles and I've sold several to other instructors here at Gunsite, none of us has ever had an accuracy issue, in fact every gun shoots better with the can in place.
The Surefire units are slightly less quiet, but the K is shorter and lighter than the QS.
Zero shift is minor and repeatable in all cases, the SF has the least shift, then the SS and then the HVT. Of course, the HVT is all steel and quite a bit heavier. Shift on the 20" .308 is 1.75 MOA down and .75 right, I've just got it dialed in as an offset in my FFS progeam.
Excepting the .338, I really don't have a need for the quick attach feature, where having the break in place when the can is not installed is a big deal. That's why I use the Sandstorm on my current new build. I'd rather save the weight and length, thread mount is no problem. Unless you have multiple guns with varying thread patterns for which an adapter is available, I would just use the Sandstorm. Since you want to down size to 5.56 guns, make sure you can in fact get the mount you want. I don't recall SF making a 1/2-28 mount for the 762 series of cans.