Thanks Daryl , yes Nitro proofed for a "Superior Load" but I don't know what that is & no load info on the rifle . I even rang the proof house but they could not help !

I did find on this sight reference to an old chart - 9 Drams for 1859Fps and one at 1806Fps

And H4227 is made by ADI as AR2205 - might try that next !

Thank you for your email help also !