At the club today, I was able to test some new 7.5x55mm Swiss handloads. It was fitfully cold which made shooting for accuracy a wee bit difficult.
But I managed to do my best to eliminate shivering on the ground. My rifle shoots very well so the main variable was the test ammunition I had loaded. Using one bullet and one powder for all loads left the powder charge and the different case manufacturers remaining as the “X” factor.
First up was the Swedish Norma brass. Starting with the slowest load of 40.5grs. of IMR-4895, all rounds impacted low in a group of about 5 inches. Next, 41.0grs. yielded similar results. Moving on, the load firing 41.5grs. really improved. The group shrunk to about 3″ and impacted higher on the target near center. The last test load of 42.0grs. impacted nearly in the same same place but the group opened up to almost 4 inches.
The next series was fired with the same powder charges loaded into Frontier brass. This run did not go well across the board. From slow to fast, the groups ballooned into shotgun patterns!
The last series followed the same powder charges loaded into Portugese FNM brass. The results closely mirrored the results of the Norma brass with one exception. The load weighing 41.5grs. grouped in at around 2.75 inches! Now I have something to work with. I have about two months before the Swiss rifle season begins and warmer testing and practice weather to look forward to.