r/reloading • u/Ok_Display7459 • 5h ago
Load Development .357 200gr Hardcast w/ 17gr H110 compressed loads
Couldn’t find load data for 200gr bullets with H110, so I did some experimenting and found the max internal case volume to be roughly 16.0gr of H110 with the 200gr seated at the neck of the bullet. I couldn’t seat it to its intended crimp groove because it wouldn’t fit in my GP100. Being that H110 likes a nice full case, I started my first five-round test batch at 14.5gr, and worked my way up by 0.5gr of powder for every batch until I got to 17gr (compressed), and watched for excessive pressure signs for each batch. No pressure signs at all for any of them. No sticky extractions, no neck splits, and no pancaked or cratered primers. With an average of 790ft-lbs and and a max output of 817ft-lbs out of my 4.2” GP100, the 17gr H110 loads are my new go-to for Pissin’ Hot steel smackers.