Loading the 357 Super Mag, I do not call it a Max, for a simgle shot does not require any crimp at all. But if you must crimp, seat first and then use a taper crimp untill the case is straight only, as a separate stage or station. I expanded the mouth my cases just enough to start the base. You will find the best accuracy without a crimp, just increase the heat of the primer. I mostly shoot 200 grain very hard cast bullets or the Rem 200 RN. The 200 Rem was deigned for the 35 Rem cartridge and the SM will like that bullet.
With 296/H-110 (same) use small rifle primers at least. You should do the same with AA #9. I use 205m Federals with H-110 in the single shots. Cruising ptessure on the SM was designed to be 50k psi. Flattening primers starts about 55k, a TC will definitely load up to flatten primers. . The SMs, all, were originally designed on a TC frame by Elgin Gates, the 357 SM was done using two 357 Mag cases silvered soldered together, got one shot per case. Only used to prove the theory.
Steve Vogel Executive VP Ruger sent me two of the first SRM guns. I have owned SM guns since well before there was any ammunition, since, I have owned a few SMs including Contenders, BFs, Merrills, Martinis, Sevilles, El Daradoes, and a dozen 357 SM Dans made by Seth Wesson, also 445s and 3755s and these 3 custom guns, I built. including the revolver on a SM frame.
May help to know that the 357 SM case has the same case capacity as the 7 BR, 6 BR or the 7 TCU. It can, in a single shot, use the same powders. All you need do is work up the load.
L is the walnut Martini 357 SM, M. is the Maple 357 SM Martini, R. is the DW SS 357 SM / 30 cal
