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Discussion Starter · #1 · (Edited)
Ever have a rifle that just doesn't wanna shoot? Most of mine are like that. Seasoned reloaders know that the closer to the lands you can get the bullet, the tighter the group will be, right? Sometimes... Some time ago, I corresponded with Walt Berger of Berger bullets and he recommended I always inclulde a rough seating depth test to see about where your rifle likes to shoot those particular bullets. He said, depending upon the caliber, start about 2 grains below max, which was about 3% below max recommended charge for that caliber (as always, be sure that charge is safe by starting low and working your way up), and load up 6 rounds of incremental seating depths. Start at .010" off the lands for the first 6 and repeat by loading up 6 more, .040" deeper into the case. Load 4 sets of 6 rounds at .040" increments (.010", .050", .090" and .130"). One of these sets will group noticeably tighter than the rest and it isn't always the one closest to the rifling.

I have a 338 win mag I recently had bedded. I loaded up 3 sets of 5 bullets at various seating depths. I decided to shoot round robin and all the groups were horrible after just 2 shots so I stopped and looked closer at the gun. I went home and took it apart and found out the bedding job was not right. I took it back and the gunsmith agreed and re-bedded it. The scope was also slipping due to recoil so I lapped the rings and added some friction paper. I took the rifle out today and decided to finish off the three remaining rounds of each set that I had left. Since my magazine doesn't allow me to seat the bullets anywhere near the lands, I started with a COL (case overall length) of 2.330". The next set was .040" deeper into the case at a COL of 2.290" and the final set was again, .040" deeper at a COL of 2.250". I did not shoot round robin this time. I shot a spare round to warm the barrel up and shot each set straight through with 5 minutes between shots and 15 minutes between sets to let the barrel cool down. The groups in the picture go from left to right with the bullets seated furthest out on the left and the bullets seated deepest into the case on the right. Left group= COL of 2.330" (2-1/2 inch group). Middle group= COL of 2.290" (7 inch group). Right group= COL of 2.250" (1/2 inch group).

I should have tested with 6 bullets of each seating depth but I just wanted to burn up what I had left before I started over again with load development. Point being... you gun likes what it likes. Consider a rough seating depth test before giving up on a bullet.
 

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