97th Signalman
Member
I am often puzzled by the differences in recommended loads in various manuals. The two books that I consult most often are the Speer manual (my favorite) and the Hornady manual. Lately I have been trying to develop loads using Alliant Power Pistol powder for my 9mm handguns using 124 grain FMJ bullets. The Speer loads are based in using Speer brass, Speer bullets and CCI 500 primers. The Hornady recommendations use Hornady brass and bullets with Winchester SP primers. Both have C.O.L. of 1.150”
The Hornady Manual shows a starting load of 4.3 grains of Power Pistol (900 fps) and a max load of 5.7 grains (1100 fps).
The Speer Manual has a starting load of 5.6 grains of Power Pistol (1033 fps) and a max load of 6.4 grains (1157 fps).
As you can see, the max load in the Hornady book (5.7 grains) is approximately equal to the starting load (5.6 grains) in the Speer book. Stuff like this really baffles me. I have tested loads of 6.2 grains behind 124 FMJ bullets. They have noticeably more felt recoil than my rather mild standard Unique reloads with 115 FMJ bullets but they shoot to the POA where as the 115 grain bullets tend to shoot several inches below my POA. I don’t see any signs of severe overpressure using the 6.2 grain Power Pistol charge in either my S&P M&P9 or my CZ-75. There may be slight bit of primer cratering in the M&P9 since you get that weird tear drop marking on the primer from the indent around the pin on the bolt face. I see nothing that would indicate overpressure on the brass fired in the CZ-75. The felt recoil of the 6.2 grain charge feels about the same as that from using the Winchester NATO ammo that is about 10% higher in pressure than SAAMI standards.
Should I feel confident that the 6.2 grain charge is safe based on the Speer manual or should I be more cautious based on the more conservative max charge of 5.7 grains listed in the Hornady manual?
The Hornady Manual shows a starting load of 4.3 grains of Power Pistol (900 fps) and a max load of 5.7 grains (1100 fps).
The Speer Manual has a starting load of 5.6 grains of Power Pistol (1033 fps) and a max load of 6.4 grains (1157 fps).
As you can see, the max load in the Hornady book (5.7 grains) is approximately equal to the starting load (5.6 grains) in the Speer book. Stuff like this really baffles me. I have tested loads of 6.2 grains behind 124 FMJ bullets. They have noticeably more felt recoil than my rather mild standard Unique reloads with 115 FMJ bullets but they shoot to the POA where as the 115 grain bullets tend to shoot several inches below my POA. I don’t see any signs of severe overpressure using the 6.2 grain Power Pistol charge in either my S&P M&P9 or my CZ-75. There may be slight bit of primer cratering in the M&P9 since you get that weird tear drop marking on the primer from the indent around the pin on the bolt face. I see nothing that would indicate overpressure on the brass fired in the CZ-75. The felt recoil of the 6.2 grain charge feels about the same as that from using the Winchester NATO ammo that is about 10% higher in pressure than SAAMI standards.
Should I feel confident that the 6.2 grain charge is safe based on the Speer manual or should I be more cautious based on the more conservative max charge of 5.7 grains listed in the Hornady manual?
