Does anyone have a Quickload or other source to suggest powders and charge weights for the 416 Rigby that would duplicate 450/400 ballistics - 400 grain bullet @ 2150 fps?

The two case's capacities aren't that different, about 10%. A powder deemed ok for the 450/400 should work in the Rigby as well. My books are still in boxes after a recent move, but I'm sure the A-Square manual has loads for the 450/400. Re15 would likely work, but check the book. Come to think of it, the .416 is surely covered in that same book, and they generally offer reduced loads, one of which might be what you're after. All loads there are pressure tested.

Thanks asdf: That seems a good idea, I'll try that.

OK, I finally dug out my books. Neither the A-Square manual nor the latest Hodgdon manual has reduced loads for the .416 down to 450/400 levels. Both are recommending large charges of slow powder (4831 class), and reducing these greatly is generally frowned upon. A-Square's 450/400 data uses large charges of these slow powder as well, but the somewhat bigger .416 case puts you into uncharted territory.

Lyman 48 has loads down to 2200 fps with 4350, but these apparently were not pressure tested.

The big Rigby case along with it's low working pressure suggests it was originally loaded with cordite. Search these forums for information on cordite substitutions. Many seem to feel the old cordite charge can be scaled to get the correct charge of Reloder 15. The big debate is whether one should try to use a filler. A certain primer is always used with this formula as well, some hot Federal job.

As for QuickLoad, it suggests a nearly full case of powders such as Reloder 22 will do the job as will a case about 3/4 full of Reloder 15. The program does NOT claim, though, to be able to predict powder performance at these lower pressures.

Good luck.

AK,
the hornady book as some 2120ish loads, ircc. as i give rusty static about (sure, i really download a 416 and just barely make it match your 450/400..."

heh
jeffe