Can I Use IMR4227 in 7.5 Swiss?

[Rick N Bama]

I have an almost full can of IMR4227 that I would like to use in the 7.5 Swiss rounds I'll be loading tomorrow. The boolit is the 311407 from the group buy & weighs around 175grs ready to load.

My Lyman #47 manual shows a starting charge of 25grs for a 180gr boolit loaded in a 308 Winchester round.

Can I safely use this powder for my loads? I'm after accuracy and possibly using it for Whitetails.

FWIW, I've only been shooting cast for about a year now and in my rifles, 2400 is the only powder I've tried.

Thanks to all,

Rick

[Maven]

Rick, Yes you can, but I'd be happier if you reduced the charge to 22gr. If it doesn't perform well, increase it in 0.5gr. increments up to 24gr. Go to 25gr. only if you need the higher velocity.

[Buckshot]

............I'm with Maven. I don't think 25.0grs would be dangerous or hurt anything, it just isn't a place to start. I use 23.0grs of H4198 (which is slower) in a 30-06 (which is a larger case) under a Lyman 311284 (which at 215gr is a heavier slug) and it goes 1650 fps. If you're after the velocity do as Maven said and load increading charges. Watch your groups.

4227 is a great powder with no surprises and has been a favorite Schuetzen powder since forever . It's capable of some really outstanding accuracy with low ES's.

...............Buckshot

[Rick N Bama]

Ok, 22grs it is. I've just loaded 2 & shot them out back. They both went "Bang" and the gun didn't blow up so I guess we're off to a good start with a new powder.

Again, thanks.

Rick

[sundog]

I don't know the percent difference between 7.5 Swiss and and '06, but one of my benchmark loads in an 03 is 21.0/4227 with 180ish boolits. Yields ~1625 fps. Wins mil bolt matches sometimes, too. Like Maven said, run up and down a couple grains in 0.5 gr increments. Sooty necks means too little powder. Blossoming groups mean too much powder. Can you neck size? 4227 is an excellent cast boolit powder and worth working with. Range report required! sundog