Joe,
I understood the action was an "intermediate" length,not Kurz.
I agree that about the only way to avoid altering the action would be to barrel mount the scope. He could use a different bolt body (and save the original)and bend it some to gain a little room, but not enough to notch the action.He could also use a different trigger guard assy to open up for Dst,and save the orig.with the bolt body. A 6x57(using 244 reamer and dies) seems like an excellent caliber choice for varmits and deer.
Mike