NitroX:

My hunting partner has a Krieghoff .500/.416 (with extra 20 bore and .375 Flanged Magnum barrels) that I've shot quite a bit.

As noted above, standard ballistics for it were developed in 25,5" barrels and the Krieghoff barrels are 23,5". I chronographed three lots of Krieghoff factory (Wolfgang Romey) ammo and none came up to 2300 fps, averaged around 2260. This stuff was pretty erractic and accuracy wasn't great.

We worked up a load using Krieghoff's recipe of H1000, Federal 215 primers and 410 grain Woodleighs in new Bell cases. 107.5 grains H1000 gave 2250 fps and excellent accuracy. Heavier charges gave slightly higher velocity, but produced immediate and significant vertical dispersion.

Hmmm. So, with 410 grain bullets the .500/.416 gives 125 fps more velocity than the 400 grain .450/.400 3" NE, but does so at the expense, despite the larger .500 case, of 18 tons pressure vs 16 tons for the .450/.400. It falls 150 fps short of the .416 Rigby. Traditionally, 18 tons has been considered rather high pressure for use in a double. It is too early to tell if the .500/.416 rifles will come off face prematurely and it may work out fine in the new doubles with their modern steels. I suspect it will be OK.

Ted's rifle functions smoothly, is pleasant to shoot and is very accurate with both rifle barrel sets. The .416 often gives 2.5" 4 shot groups at 100 with sights (these barrels are not scoped) and the .375 (1.5-5X Leupold) will stay in 1.5" at 100 with 300 grain Woodleighs but 270 grain produce buckshot patterns. Hard not to like a double rifle that shoots like that. Pity about the safety though.

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