Alan, I tried my 357max barrel (before it became a 35 Rem) on a 2003 Topper SB1 frame a few years ago, I shot about 6 rounds of the Dan Wesson factory ammo thru it, all had pierced primers, the larger shotgun firing pin and surrounding hole makes the SB1 frame unsuitable for the higher pressure of even pistol rounds, you have to remember that shotgun pressures are no higher the 14kpsi. Please see the rifle barrel on a shotgun frame info in the FAQs, it's not worth life and limb to save a few bucks, follow LaOtto's advice and get an SB2 frame for the Max.
Tim