I decided to try giving the 180 grain Swift Scirocco II a whirl in my .300 Winchester Magnum again after letting them sit on the shelf for the last 7 seasons. When I tried them before I was pretty methodical, but started them close to the lands and worked deeper until I gave up. Nothing seemed to work at that time, and I finally scrapped the idea.
Since then some ideas of how to work up loads by seating depth have become a little more published and accepted and I read the article of how to get Berger VLD hunting bullets to group. I had already tried from the long end of things so I mixed it up a little bit and decided to start from the shortest OAL I could go and move them out in .040" increments. I don't have the measurements sitting here with me so for the pictures just know that Seating Depth 1 is the furthest I dared push the bullet in the case and then each depth is .040" further out.
I fired the three shot groups in this order 1,2,3,4,4,3,2,1.
Anyway, it appears that with no adjustment other than seating depth that what the article says is true...there would be one group that was significantly better than the others. The average size of the two groups at Depth #4 was better than the other three. What is throwing me a littel is the fact that the last group I shot was the .404" group at seating depth #1, making the average on that setting acceptable.
I am thinking I need to load up nine rounds at each of Depth 1 and Depth 4 and fire three, three shot groups of each of those to see if the groups hold, and which one is actually more consistent. However, if I think too long I think I should go with Depth 4 and start tinkering with powder adjustments as it was the tighter group, and the impacts were a little more triangular.
The images are in order of seating depth 1-4
Thoughts?
Since then some ideas of how to work up loads by seating depth have become a little more published and accepted and I read the article of how to get Berger VLD hunting bullets to group. I had already tried from the long end of things so I mixed it up a little bit and decided to start from the shortest OAL I could go and move them out in .040" increments. I don't have the measurements sitting here with me so for the pictures just know that Seating Depth 1 is the furthest I dared push the bullet in the case and then each depth is .040" further out.
I fired the three shot groups in this order 1,2,3,4,4,3,2,1.
Anyway, it appears that with no adjustment other than seating depth that what the article says is true...there would be one group that was significantly better than the others. The average size of the two groups at Depth #4 was better than the other three. What is throwing me a littel is the fact that the last group I shot was the .404" group at seating depth #1, making the average on that setting acceptable.
I am thinking I need to load up nine rounds at each of Depth 1 and Depth 4 and fire three, three shot groups of each of those to see if the groups hold, and which one is actually more consistent. However, if I think too long I think I should go with Depth 4 and start tinkering with powder adjustments as it was the tighter group, and the impacts were a little more triangular.
The images are in order of seating depth 1-4
Thoughts?
