You will probably also need 7.2" spacing to reach back far enough to prevent stock crawling. The next width is 10.8" which is a bit less convenient (3 units per C" at X00 yds) and moves the rear most scope position 3.6" further forward.

You do not need and probably don't want a recoil return spring, thought I suspect in a .220 Swift recoil is pretty minimal.


_________
BrentD, (Professor - just for Stan)

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