Can the 458wm be loaded with reduced loads of H4895 ?
I never heard of this before but just read on hodgdon website that i can take the max load and multiply by .6 and start there.
So my load of a 350gr.bullet with published 80gr.charge of H4895 is 80x.6=48
I had no idea i could load that low a charge.
How can i calculate the speed?
Has anyone else use this powder reduced and did you ever have any proplems?
Do you think at 48 grains the velocity would be around 1500fps.?

Ok i finally got to try 60 gr. H4895 WITH 350GR.HORNADY RN. In the 458wm.
The round fired just fine but i wonder what my speed is running.1750-1800?

Probably about 1900.

This was calculated from your 60-grain charge divided by the 80-grain maximum charge listed for 350's by Hodgdon, which gives slightly under 2500 fps in their 24" test barrel. One nice thing about single-based rifle powders is they're very predictable: Within normal pressures, velocity increases or decreases at the same rate as the powder charge.

Thanks for the help John.
I loaded some more last night with 68gr. I hope to be around 2,100fps.?
Will shoot them when i get time.should be fun and hopefully accurate!
So far i really like the H4895 powder.

It's great powder. You should get around 2100 with 68 grains, though you never know unless actually chronographing the load.

How fast should 400gr.speers run with 65 grain H4895?Any ideas?
Would like to duplicate the 404 Jeffery old tyme load of 60gr. Cordite@2050fps
I dont know anyone who shoots either the 458wm or the 404 jeffery...and i dont have a crony.

Speer shows 2300 fps at 76 grains with the 350 grain bullet. No data for the 400 but you could compare it to the 45-70 loads for a cross reference.

Looking at Hodgedon data: https://www.hodgdonreloading.com/data/rifle a WAG number of about 68-70 grains will get you into the 450/400 or 404 Jeffrey range. Since this is below the starting load you could just begin at 68 grains and work up to see if you can get good accuracy.

I have used H4895 with 6 or 7 different cartridge and it is VERY predictable. What ever percentage you drop from the max load, you will get a equal drop in speed. A 40% reduction of a max load should equal a 40% drop in speed.

I will give you the numbers if you can explain why you are asking the question on the Reloading Software Forum.