Hi all. I've been lurking for a bit, but this is my first post...I hope this is the right forum for this question. Be gentle!
Curious to know what your thought would be on this question.
I recently developed a load for my S&W 1854 lever gun in 44 Magnum. It spits a Rim Rock 255 gr (260 actual) Keith SWK-G/C bullet at 1720 fps from a 19" barrel. Bullet sits atop 23 gr. H110 with WLP primers. The load was holding multiple 5 shot 1" groups at 50 yards from my rifle with open sights. Extreme spread was 25 and Std. Deviation was 10.4. This is a pretty hot load but doesn't quite max out based on load data I've found on LoadData.com.
Recently I received some 280 gr (279gr actual) Montana Bullet Co. WFN-GC bullets. Given that they are 20gr heavier, my initial plan was to back down to about 21-22gr H110. But upon closer inspection, I also recognized that these bullets are shorter behind the crimp groove than the RimRock 255's, which then effectively decreases seating depth. I also have to consider that H110 likes a full case of powder and very little air space for maximum consistency and minimum deviation. Reducing the charge would be working against me in this regard.
So, that left me to wonder, should I keep my load at 23 gr given the bullet isn't seated as deeply, or back it down? In other words, how much consideration should I give to bullet depth vs. bullet weight when building up a load? My goal would be to get this 280 gr slug above 1600fps and to maintain the accuracy I achieved with the Rim Rock bullet.
Thoughts?