Downloading Magnums

[ZeroJunk]

Has anybody had any accuracy success with light loads in something like a 300WBY.I tried with H4831SC and got a 6 inch group.Would a faster burning powder work better or is it a lost cause.Was aiming for something in the range of a 30/06 factory load.

 

[rnovi]

Zero,

First off, good on you for trying to download such a big cartridge to make it more shootable on a daily basis. I do the same thing with my .350 Rem Mag - it's a lotta fun and I have even worked up Bunny loads using pistol bullets.

BUT, and I do mean BUT, do NOT go into this blind. An undercharged case can be just as dangerous as an overcharge! The first thing I am going to recommend is to go to www.midwayusa.com and buy a "Loadbooks USA" on your cartridge. They are around $8 or so and contain ALL the load data from any published resource on your cartridge in one place. I'm very willing to bet that someone (Speer, Lyman come readily to mind) have already worked up reduced power loads for you.

Start there.

IF nothing is available, send me a PM or the like and we can exchange phone numbers. I'll be glad to tell you how I go about creating a reduced load - but I'm sure not going public with it lest someone mis-interpret something and get in trouble!

 

[toolguyb]

Zero

I download my 300 wby. I use IMR 3031, 58 grns, and 180 grn rem psp.
I have wrote down 2700 fps.

rnovi is correct about the danger of downloading powder charges. I also would make sure that I only used a published data.

 

[ZeroJunk]

Thanks for the responses.I don't want to go below the published minimums.My problem has been that I can't seem to find one that is accurate.

 

[Mike Irwin]

Downloading a magnum-size cartridge often creates a huge dropoff in accuracy.

The cases are just too large and the pressure curves to erratic.