Determining the correct powder grains

[wiiawiwb]

I've been reloading 45LC for the past month and am thinking ahead about reloading for 454 Casull. I have a Ruger SRH Toklat in 454 Casull that I've been shooting the 45LC with.

I ordered some 315 grain flat-nose, gas-check bullets from Matt's Bullets. How do I go about determining how many grains of Unique to use with this bullet?

http://www.mattsbullets.com/index.php?main_page=product_info&cPath=71&products_id=257

My Lymans 49th Edition shows 11.3 starting grains of Unique with a 325 gr (linotype) lead bullet (#452651). That yields a velocity of 1,103 and pressure of 38,300. Should I back off the 11.3 grains by 4% (315 grains vs 325 grains) and use 10.9 grains or add 4%?

Any suggestions or alternatives would be greatly appreciated.

 

[matrem]

Delete.

 

[Sam1911]

Generally speaking, you'd be safe with using the same load for the slightly lighter bullet. Then work your load as normal.

 

[Reloadron]

Neither, but as a point of reference as bullet weight increases the powder charge decreases. As to your load? You can call the bullet manufacturer for suggestions. That said I would likely start with 11.3 grains of Unique. The difference in bullet weight between 325 grains and your 315 grains isn't all that great, not enough that I would worry about it. I would use the 11.3 grains as a start load and work up from there. The shown range is 11.3 to 12.6 for the 325 grain Linotype bullet so you have a good margin in there. This is purely my thinking so see what others have to say.

Damn, used all those words to say what SAM said in a single sentence.

Ron