Hoping German Salazar sees this, as he seems to shoot more of the Lapua D46 than anyone. 
Worked up some loads for my Tikka Master Continental in .308 (26" heavy barrel) and went to the range Sunday. Set up at 200yds and fired some 168g Fed. GMM to make sure I was still zeroed. Three shot group of just under an inch was just below my aiming point - at a previous range session I had zeroed it at 100y. I then started working though the following loads:
IMR 4064 -- 39, 39.5, 40 & 45g
VV N140 -- 41.5, 42, 42.5, 43g
RL 17 -- 45, 45.5, 46, 46.5g
Three rounds of each were loaded in new Winchester cases with Fed. 210 Match primers, with an overall length of 2.80 and a neck tension of .002. These particular D46's are .309 in diameter. Elevation was 600' above sea level, weather about 85F and humid with light wind.
I started with the lightest of each load, but here's the deal - all the rounds hit 8 - 10" below my aiming point. I figured I would be somewhat lower than the GMM, but only by a couple of inches at most. When I realized they were off the paper I skipped ahead to the heavier loads and raised my aiming point. While a couple of the loads - notably 46g of RL17 - grouped pretty well, they were still about 8"low.
As I don't (yet) have a chronograph I was relying on published load data for ballpark MVs. In hindsight I could have set it up as a ladder test, but I figured I would be hitting a bit closer to POA than I did! I ran the D46 through the Lapua ballistics calculator using a 100y zero, and it showed a drop to 200y of 5" for a MV of 2300 and just over 4" for 2400, so a low MV may have been part of it. Been mulling it over and came up with the following possibilities:
1. My Tikka's chamber has a generous leade and I wasn't generating enough pressure to get decent MVs.
2. Loads had lower pressure for a particular charge due to the higher ICC of Win. brass.
3. Even though I was in the higher half of published loads for these powders, they may have been somewhat below the maximum for this particular rifle.
4. This particular Tikka doesn't like Finnish bullets!
Any guidance/suggestions anyone can give are welcome. Realize it's tough without chronograph readings, but I figured you guys have seen enough to narrow down the possibilities.
Thanks in advance,
John
Worked up some loads for my Tikka Master Continental in .308 (26" heavy barrel) and went to the range Sunday. Set up at 200yds and fired some 168g Fed. GMM to make sure I was still zeroed. Three shot group of just under an inch was just below my aiming point - at a previous range session I had zeroed it at 100y. I then started working though the following loads:
IMR 4064 -- 39, 39.5, 40 & 45g
VV N140 -- 41.5, 42, 42.5, 43g
RL 17 -- 45, 45.5, 46, 46.5g
Three rounds of each were loaded in new Winchester cases with Fed. 210 Match primers, with an overall length of 2.80 and a neck tension of .002. These particular D46's are .309 in diameter. Elevation was 600' above sea level, weather about 85F and humid with light wind.
I started with the lightest of each load, but here's the deal - all the rounds hit 8 - 10" below my aiming point. I figured I would be somewhat lower than the GMM, but only by a couple of inches at most. When I realized they were off the paper I skipped ahead to the heavier loads and raised my aiming point. While a couple of the loads - notably 46g of RL17 - grouped pretty well, they were still about 8"low.
As I don't (yet) have a chronograph I was relying on published load data for ballpark MVs. In hindsight I could have set it up as a ladder test, but I figured I would be hitting a bit closer to POA than I did! I ran the D46 through the Lapua ballistics calculator using a 100y zero, and it showed a drop to 200y of 5" for a MV of 2300 and just over 4" for 2400, so a low MV may have been part of it. Been mulling it over and came up with the following possibilities:
1. My Tikka's chamber has a generous leade and I wasn't generating enough pressure to get decent MVs.
2. Loads had lower pressure for a particular charge due to the higher ICC of Win. brass.
3. Even though I was in the higher half of published loads for these powders, they may have been somewhat below the maximum for this particular rifle.
4. This particular Tikka doesn't like Finnish bullets!
Any guidance/suggestions anyone can give are welcome. Realize it's tough without chronograph readings, but I figured you guys have seen enough to narrow down the possibilities.
Thanks in advance,
John
