Probably been discussed before, but I am looking for feedback from someone with first-hand experience using the two mentioned powders.
I have two different 450 3/14" guns, one a double, the other a single-shot falling block. I have used imr in both, but lately can't find any.
In every burn rate chart I find, they put the two powders side by side. Is anyone using H4198 in their guns, and what kind of loads? I have been using 325 gr paper-patched bullets as well as 350 gr jacketed bullets, both over 42 grains of IMR4198. This is a bit lower than I have seen most people report with this load, but it regulates extremely well in my double rifle.
What would be the best way to proceed with H4198?

Sorry for the typo! It should read 450 3 1/4" guns!

I have used IMR4198 and H4198 in my H.Holland double, I could tell no difference. My loads use a 300 grain PP bullet over 46 grains of 4198, dacron filler. My groups average in the three to four-inch range at 100 yds. The rifle has seen better days, as have my eyes.

I have used both. IMR 4198 is my favorite--either becsue it works so well or because I have so much of it I need to use it. In my bpe doubles I shoot nitro for black and a 1:1 ratio. Individual rifles may vary a bit but it is a very close ball park.

I have shot H powders and they seem a bit slower and 1-2% more powder is needed to obtain the same velocity.

Others may post differtney but this is my experience.
Cal

I use H4198 in my Nitro for Black loads, .450, .500, .577
For my two .450 3-1/4” BPE’s it is 45grains of H4198, 325g HP Paper Patch or 365g solid Paper Patch, foam backer rod, and Fed 215 primers. The bullets are patched to actual groove diameter when I use smokeless.
- Mike