Home Forums Reloading Big Game Rifles Hammer Hunters in 6.5 WSM

Update on progress:

I used my previous data from the 125 Bulldozer as a basis for the 124 Hammer velocity test loads. The 4 test loads got 3174, 3252, 3367, 3392 fps. No hard bolt lift and no flattened primers for any of the 4 loads. I did notice a faint ejector mark with the heaviest charge.

Next was some 5-shot groups of increasing charges at 100 yards. Charges were 66.0, 66.5, 67.0 and 67.5 gr Ramshot Magnum. Velocities of the groups averaged from 3251 to 3294 fps. SD varied from 18 to 90. Group sizes ranged from 0.57 to 0.93". I don't know about the set that had a extreme spread of 195 and SD of 90, although the group size was 0.82". The brass that averaged 3294 showed some ejector marks. Next will be to vary the seating depth of the load that gave the SD of 18, from 0.02 to 0.10 off the lands.

After shooting the 5-shots groups with increasing charges, I chose the charge of 67.5 gr Ramshot Magnum to try different seating depths even though Hammer Bullets says it does not make much difference.  I chose 67.5 gr as it had the best combination of ES and group size from the previous set.  I loaded up 5 rounds each with the bullet seated 0.018, 0.045, 0.070 and 0.095" off the lands.  This morning I went out and shot the groups at 100 yards and allowed 6-7 minutes between rounds for the barrel to cool.  I started with the 0.095" off (labeled 3.275 COAL on the target) figuring the pressure would increase as the bullet was seated closer to the lands.

For the target images, 3.275 COAL corresponds to 0.095" off, 3.300=0.070, 3.325=0.045 and 3.352=0.018   The AVE VEL on the target table includes numbers for average velocity, extreme spread and standard deviation in that order.  Chronograph was a ProChrono at 10'.  Rifle is a Winchester 70 with 26" 1:8 Shilen barrel threaded with Omega Suppressor.