The test platform was an Empire Rifles Mauser action with Wiseman barrel, Bell and Carlson stock and a Schmidt & Bender 1.5-6X scope set in New England Custom Gun scope rings.

The rifle George had put together was his standard grade African-style with the following options: dropped magazine to hold one extra round (four in the box instead of three), iron sights and a barrel band front swivel. George’s controlled-round feed Mauser-type actions in both standard and magnum length, for right-handers and lefties, are built exclusively for him here in the States.

Extraction and ejection are purely Mauser, but the safety is basically Model 70 Winchester, with a horizontal-swinging three-position wing on the bolt shroud that withdraws the striker assembly from contact with the trigger sear. The trigger itself is manufactured in Germany by Recknagel and is similar to that of the Remington 700. It broke at a very crisp and creepless 31⁄2 pounds.

The barrel is a 22-incher button rifled and fitted by Bill Wiseman, one of the most respected custom barrel and rifle makers in the country. The test gun wore a Bell and Carlson Aramid fiber synthetic stock with an integral aluminum bedding block. The gun arrived already fitted with a 1.5-6X Schmidt & Bender scope, and ready to go the test gun weighed 111⁄4 pounds, about right for a rifle of this type, caliber and intended use.

Included with the Redding dies was a tapered expander that allowed me to neck up the .375 Ruger brass to .416 inch in one pass. I then sized the necked-up cases, adjusting the sizing die to just kiss the shoulder enough to give a little resistance to the down stroke of the bolt handle.

After running all the cases through the resizing die, I was ready to pick a powder and a starting load. Before doing so, however, I again checked the comparative case volumes of the .416 Remington Magnum and my .416 JRS.

Empty, the two cases are literally identical in weight: 260 grains. Filled with water to the case mouth, the Remington case holds 105 grains of water, the Ruger 100. But the .416 Remington Magnum case has a longer neck, so when I reduced the water lever in both cases to where it was even with the base of the neck--which is the real measure of case volume--both held 89 grains of water by weight.

The reason for these machinations was simple: with both cases being of identical capacity, I knew I could safely use any published starting load for the .416 Remington Magnum in developing loads for my wildcat.

Checking four reloading sources--Barnes, Hornady, Nosler and Speer reloading manuals--the consensus had Reloder 15 as the top-performing powder. Taking the starting loads listed in all four manuals for a 400-grain bullet and averaging them, I came up with 75.5 grains. The average maximum load was 80 grains on the nose.

Just to be safe, I started with 74.0 and loaded three rounds each in one-grain increments up to 79 grains, color coding the bases with felt tipped markers and recording each as I went along. With three rounds each of six different loads, I packed up my shooting gear--including my Caldwell Lead Sled (I’m not stupid)--and chronograph and headed for the range.

I fully expected to match the nominal 2,400 fps listed for Remington’s 400-grain factory load, and I wasn’t disappointed. Big bore cartridges suffer less velocity loss than smaller calibers as barrels are cut back from the 24-inch norm used in establishing factory ammo velocities, so I figured if I could get 2,350 fps out of the test gun’s 22-inch spout, that would essentially meet my goal. As it turned out, using Hornady’s 400-grain softpoint, I achieved 2,405 fps with a mere 75 grains of Reloder 15--with no signs of excessive pressure.