Ijust obtained a new Japanese made Winchester 73 in 45 Colt. It has a 20 inch barrel
I tried 9.0 grains of CFE Pistol which is supposed to be around 13,000 psi. Using Star-line brass, a Win stan/mag primer and heavy roll crimp into some mystery 250 grain rounded flat point cast bullets with a beveled base. They are .452 to .453.
This load averaged 1120 fps from the 20 inch M-73 and 900 fps from a 5.5 inch Uberti SAA.
But it was still a 1.5 inch to 2.o inch groups at only 25 yards from the rifle. Over a sandbag.
The same load shot a 2.5 inch group from the 5.5 inch SAA off hand.
NOTE: My original 1892 in 38wcf will shoot cloverleafs at 50 yards with hand-loads if I use jacketed bullets. So it is probably not me.
The next load was 8.0 grains of Unique into the same brass and primer.
This load averaged 1,082 fps from the 20 inch M-73 and only 780 fps from a 5.5 inch SAA. And this was even worse at 2.0 to 2.5 inch groups at only 25 yards. It did shoot a 1.5 inch group from the SAA at 25 yards.
While both these loads are not wimpy, bit had a lot of gas escaping back down the side of the case in two revolvers and in the rifle. So I am not obtaining a good gas seal. SEE PIC
So any ideas why I am still experiencing gas blowing back down the cases at these velocities? Any thoughts on a better load?