Do you think the recoil from a 68 would be to much for the PVS-14. I found a place that listed G force for a given caliber and the 68 was about 20% more than the 5.56. But I assume they were talking bolt guns. I used a PVS-14 with ITT tubes last weekend and all I know is that I want one LOL. I did some reading on how these units don't hold well to heavy recoil.
Edit. It's looks to be more than 20%. From a list I found the 222mag (556 not listed) at 59000 psi has 333gs. The 68 at 59000psi is at 480gs