Making a .357 Sig Luger Carbine

I started out wanting to make a .45 Luger carbine, but have decided that may be too difficult at this time. What about a .357 Sig Luger carbine with a 16 inch barrel? Would pressure be a problem? Could the bolt block be enlagred enough? I think the .357 Sig is based on the .40 S&W case. Would it function without a spring in the forearm like the 1902. I think using the .357 Sig only one frame would be used, thus saving another luger. Or again maybe use a stainless steel luger. Any ideas?