The G7 turret cap is only for the ZeroStop model. If you had the ZeroStop adjustment on your scope, you could just replace the cap with the G7 Ballistic Cap.
For Non-Zero Stop BDC caps, look at Kenton Industries.
There is also someone making mylar laminated tape strips that are printed with your ballistic data. They are reusable as well as come in several DA's (density altitude).