Does anyone have a "relative difference" between these two powders. Say if it calls for 90 gr of IMR, would the Hodgdon powder need a bit more due to its slightly slower burn rate? I am reloading for a 450 NE and want to try some 4831 (short cut version) that I have a fair amount of, and don't want to go buy the IMR version. I am having good luck so far with RL15 w/o a filler....but there is a tiny airspace.

Thanks in advance for the responses.

Gary
DRSS
NRA Lifer
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The exact difference will be depend on the case size bullet pressure etc. H4831 is normally 2-3 grs slower than IMR. Meaning you can use more H4831. If your load data calls for IMR4831 you should be safe is starting with H4831 and working up.

i find that imr 4831 is about half way between h4831 and 4350

Thanks, gents....you all confirmed what I had calculated. I appreciate the response.

Gary
DRSS
NRA Lifer
SCI
DSC

quote:

Originally posted by GarBy:
I am having good luck so far with RL15 w/o a filler....but there is a tiny airspace.

In the flanged nitros from .400 up, if you haven't tried RL 15 with a filler, then you haven't tried RL15. I tried it without once and won't do it again. The filler makes a significant difference. I use it with filler in these cartridges, or not at all. There's no reason whatsoever to avoid using one.
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"Serious rifles have two barrels, everything else just burns gunpowder."

400.....I agree 100% with what you say. I load for my 470 NE and it uses the Kynoch foam wad and between 89 and 90 gr of RL15 depending upon which bullet I'm using. I think the foam fillers are definitely the way to go.
With the 450 NE, though, and I get this from "Shooting the British Double" as well as some other DR guys, the 450 doesn't need a filler with RL15. Anything bigger does, but the 450 case is such that there IS a TINY airspace, but not one to cause issues. I certainly don't claim to be an expert, just going by limited experience.
I just want to try the 4831 powder to see how she shoots with it....plus it has is one of the "Extreme" powders so temp variance should be a major concern.

Thanks for your input.

Gary
DRSS
NRA Lifer
SCI
DSC