I have been told the Norma MRP is the RL22 equivalent but is also less temp sensitive.
I think they are the same damn powder but have never tried it. May be worth the research.
If you haven't tried it then obviously, you simply don't know do you?
FYI, they are
NOT the same powder............in fact they don't even look the same.
'22 is lighter (more gray), & is flatter with much more irregular sized granules than MRP which is darker, rounder granules & much more uniform in grain size.
As for MRP being less temp sensitive, I've read & been told it is but since I've not done side by side testing, I really don't know with certainty.
As far as loading goes, manuals that list both are generally very close, but
not exactly the same.
In my loading experience with both powders, I usually find that top loads with '22 are usually about a .5-1.0 grains less than with MRP........That's mainly in the 270 Win & 280 Rem where I've used both extensively.
In lots of cartridges, besides the 270 & 280, including the Rem 7 Mag & 300 & 338 Win Mags I've found that RL-22 is really hard to beat for both velocity + accuracy; never tested the extremes of it's temp sensitivity but from around +10F - around 65F, which encompasses 99% of my hunting, I don't see any issues.
'22 almost
always out performs 7828 & 4831, IME, unless you are paranoid about the temp sensitivity issue.
MM
