What NV or thermal rifle scopes are out there capable of withstanding a 50 BMG recoil force? I checked on the Thor thermals and they are not; but could be made so but only on a large order basis. I think the FLIR units like the T50 and T70 are 50 BMG rated; but their price is beyond my budget. Also appears the Armasight Vulcan NV scopes are all 50 BMG rated as is the Meopta ZN 6x; but the latter is not sold in the USA. Thanks, Dale