Boogie has done it again!! He has redesigned the '73 short stroke to be better than ever. This short stroke is made with the strict code of precision we have all come accustom to with SG Boogie Works. It is stronger than anything that is currently on the market. Made from tooled steel, hardened and retreated. What may be the most exciting new feature, are the 2 set screws to adjust the timing. No need to weld or grind like the old days. Does it fit a 45 Long Colt or a 38/357? Yes and Yes. Thats the advantage of the set screws, This short stroke can be adjusted to fit both 45LC or 38/357 in the 1873 rifle.