Interesting. I set up a similar excel formula in my reloading log file & I also found that the same bullet (225gr) with same velocity (2350 fps) in 358 Win gave different recoil with different powder / charge. A light powder like AR 2207 (H4198) versus AR 2206 (similar to IMR3031)- showed a noticeable increase in recoil with the AR2206.