270 WSM load development on the Hammer HUNTER 124 grain .277 diameter bullet. COL: 2.780 inches.
I used Lee SECOND Edition and Hornady Tenth Edition as reference material. I selected H-4350 powder. That is the one powder I had on hand that both books listed both 110 and 130 grain bullet loads so finding the charge weight in between was easy. The basic formula is using the maximum grains listed for the 130-grain bullets and insuring that that charge will not be too heavy on a 110-grain bullet. The Lee Manual lists 61.5 as max on Barnes “X”, 60.5 on JSP 130-gr. A 110-gr JSP lists 63.0 as max.
I tested three charge weights, 58,59 and 60 grains. My criteria was at least 3,100 FPS. I discovered that 58.0 grains of H-4350 averaged 3,077 FPS, 59.0 grains created a 3,237 average and 60.0 grains a slightly lower average of 3,210 FPS. No signs of pressure with any of the test loads. The best group was from the 59 grain charge .253 inches at 100 yards. The 60 grain charge produced a .323 inch group.
I selected to stick with the 59.0 grain charge, this is the combination used on a California Hog Hunt. I used the basic BulletDrop App to estimate ballistic performance. Sighted 2.0 inches high at 100 yards the zero should be around 225 yards, -4.6 at 300 yards. At that distance estimated velocity is 2,213, solid copper bullets as a rule do not expand well once speeds drop below that mark so I consider that as maximum game distance.
The boar harvested (probably 150 pound live weight) was dropped in his tracks with a shot behind the front shoulder at 100 yards. Literally the animal dropped at the shot, aside from some leg thrashing the boar never moved. Bullet passed through the opposite side in a straight pathway, exit wound was approximately twice the size. It was discovered the lungs was destroyed leaving the heart intact. I used the BulletDrop App to estimate velocity at that distance where impact occurred, that value is 2,868 fps with energy 2,265 ft-lb.
This was hog number two I shot at, missed one the day before, totally my fault. Hammer Hunters bullets worked as advertised, hollow point design penetrates and rapidly sheds pedals and the core continues to penetrate.
Rifle used is a Kimber “Montana” with Leupold VX-3 2.5-8X.
Denny McDaniels