IMR 4227 vs H4227- Sort'a OT, But gun related

[20cows]

I am trying to find a mild smokless load for a cap-n-ball to cartridge conversion. KirkD has been working on similar type loads in his vintage Smiths.

I have found some data that will help me get started using H4227. I don't have any of that, but I use IMR 4227 in my .38-55 and have plenty on hand to play with.

My burn rate chart has those two pretty close to one another. Just how close are they to being "the same"?

[RKrodle]

I have always been told they are the same powder in different cans but, reloading manuals sometimes will show both powders with a different max load. The difference isn't much. I've heard the difference explained as nothing more then lot to lot variations. Kind of like 110/296. Now, I have never set down and did a side by side comparison myself so take it for what it's worth.

[20cows]

Thanks! That's kinda' what I hoped.

[Ysabel Kid]

What caliber conversion?

[20cows]

I have a Pietta 36 caliber 1862 "Police". It's a '61 navy with a 5" barrel. I am using a Kirst Konverter.