From the below excerpt of published .32-40 loading data:
For example, two loads I recently handloaded, using a 170 grain jacketed bullet:
1. Powder is IMR 4227. Load was midway between the suggested starting grains of 14.0 and 16.5 grains, at 15.0 grains, and the velocity would be somewhere between 1034 and 1340 feet per second.
2. Powder is IMR 3031. Liad was halfway between the suggested starting grains of 25.0 and 28.0 grains, this being 26.5 grains, and velocity would be somewhere between 1512 and 1845 feet per second.
So, the LOWEST IMR 3031 velocity is 172 feet per second greater than the GREATEST velocity achieved by the MAXIMUM published load for the IMR 4227 powder. Also, the recoil felt for my two loads was significantly greater for the IMR 3031 load vs the IMR 4227 load.
So, given the maximum load is much milder than any of the IMR 3031 load, why is the maximum IMR 4227 load limited to 16.5 grains of powder?
I am well aware that different configurations of powder have different burn rates and different masses achieve a certain velocity, based on the powder, but, beyond this, how is this all interrelated and why would a perceived milder load for a given powder be maxed out well below the perceived stouter load using a different powder?
For example, two loads I recently handloaded, using a 170 grain jacketed bullet:
1. Powder is IMR 4227. Load was midway between the suggested starting grains of 14.0 and 16.5 grains, at 15.0 grains, and the velocity would be somewhere between 1034 and 1340 feet per second.
2. Powder is IMR 3031. Liad was halfway between the suggested starting grains of 25.0 and 28.0 grains, this being 26.5 grains, and velocity would be somewhere between 1512 and 1845 feet per second.
So, the LOWEST IMR 3031 velocity is 172 feet per second greater than the GREATEST velocity achieved by the MAXIMUM published load for the IMR 4227 powder. Also, the recoil felt for my two loads was significantly greater for the IMR 3031 load vs the IMR 4227 load.
So, given the maximum load is much milder than any of the IMR 3031 load, why is the maximum IMR 4227 load limited to 16.5 grains of powder?
I am well aware that different configurations of powder have different burn rates and different masses achieve a certain velocity, based on the powder, but, beyond this, how is this all interrelated and why would a perceived milder load for a given powder be maxed out well below the perceived stouter load using a different powder?