I want to load the 404 with 400grain A-Frames. I have Varget and 4831 at hand. I understand both are suitabel powders but with which one should I start? Powder supply is very difficult so I cannot afford to waste too much for trying.

I have found IMR4831 to be the best of the powders I tried in my 404 but then Varget was not made back when developing my loads.
I did try IMR4064 which is close to Varget but the Dupont 4831 beat it for accuracy.

You won't go wrong with IMR4831 but obviously not as economical as Varget.

I shoot 92 grains of IMR 4831 with a 400-grain A-Frame in my custom 404 Jeffery. This load gives me 2350 fps, which is 200 fps higher than what the original Jeffery loads produced, and about the same as .416 Rigby factory-load ballistics. The compressed load is a little on the hot side in my tight chamber and barrel, since primers start getting loose after about four loadings, but the extra ummph gives me a little more confidence when hunting in places where elephant, buffalo or rhino might take exception to your presence. (Of course, if a rhino charges, you might as well go ahead and let it skewer and stomp you, because the penalties for killing one, even in an emergency, are about the same as what the rhino will do!)

With long mono-metal solids, I use Reloader 15 (close to Varget in burn rate). Seventy-eight (78) grains gives me 2300 fps, and shoots to the same POI as the A-Frame load out to 100 yards. With shorter Woodleigh solids, I just use the same powder and load (92 grains of IMR 4831) as the A-Frame load.

Hope this helps.

84gn of H4350 was the load behind the 400gn Woodleigh in mine and gave better than 2300fps. Mild load, good case life and accuracy. I got velocity with varget but pressure signs and didn;t try the slower 4831 as the 4350 worked so well.

Ditto on the H4350.

I got about the same fps as Von Gruff on my rifle with 400 gr Woodleighs and 84 gr.

I used the H4350 with 380 gr NF SS (82 gr 2,315 fps) and 430 gr NF FPS (79.5 gr 2,200 fps). Both loaded to 3.59"

Very accurate, no pressure.

I used CCI #250 primers and Norma brass.

95 grs of IMR-4831 is the usual max load in a 404 and it got me 2600 plus a little in my 27 inch barrel Mauser and 2500 plus in the shorter tubes (24 inches)

My go to DG load has been 93 grs with 400 gr. bullets for a number of years for 2440 FPS in my present rifle...

Historically the 404 is underloaded for whatever reason, its easy to get 2400 or more with it..Keep in mind, the old loads were just that, and the 404 case has the same powder capacity as the 416 Rigby for all practical purposes and that's another one that has been traditionally underloaded, but probably for good reason as you can get plenty of velocity at low pressure in those big cases..

I personally like the magical 2400 in any big bore DG rifle as long as you can keep relatively mild pressures. Some tend to go to the extreme both directions when once again moderation is the key.

Thank you, this is all very helpful. Actually I am quite impressed by the velocities eben with mild loads.

You might want to try Varget. I have a M70 Win with a 26 inch Pac Nor barrel. I load 78 grains of Varget with 400 gn North Fork Solids and 400 gn Swift A-Frames with a Remington 9 1/2 primers. Chrongraphed velocity is 2412 for 5 shots. The extreme spread for the 5 shots is 6 fps. There are no high pressure signs. It seems to me a moderate load. Easy extraction, easy bolt lift and the primers are not flattened. I am now on the 4th reloading of the cases. Cases resize easily and the cases have not needed trimming.

Tenga cuidado

Hoot