Ccrider
Gold $$ Contributor
Following up on this post. 330 shots down the barrel now with some quality time spent wit Bart Hammers. 70 shots fired are Lapua fireform loads.
Long and short of it is that I decided that the node was around 29.9 and 30.4., depending on the seating depth chosen. I also notice that my fireform loads pushed hard into the lands shot well. So, I decided to test 15, 20 and 23 into the lands at 29.9 and 30.4 powder charge.
30.4 shot well at 15 and 20 in. And started to open up at 23 in. So, I picked 17 into the lands as a fair compromise between 15 and 20.
Next I wanted to see how wide the powder charge window was so I loaded 30.0, 30.2 and 30.4, 17 into the lands.
30.0 looked about like 29.9 did- out of tune with a lot of vertical. 30.2 was back in tune and 30.4 repeated nicely. I will try 30.5 just to see what happens. 30.2 17 in gave me zero es for three shots with a mv of 2948. Rarely have I had three shots with the exact same mv. Better still, they all went into a nice tight hole. 30.4 gave me an es of 3 and mv of 2972. A nice right group in the exact same place on the target as 30.2.
I tried a smaller neck bushing with 30.4. Hit the same place in the target but the group opened up a bit to about .19.
Last, I am having some problems with Alpha OCD brass but will not get into it until I hear back from Alpha.
Long and short of it is that I decided that the node was around 29.9 and 30.4., depending on the seating depth chosen. I also notice that my fireform loads pushed hard into the lands shot well. So, I decided to test 15, 20 and 23 into the lands at 29.9 and 30.4 powder charge.
30.4 shot well at 15 and 20 in. And started to open up at 23 in. So, I picked 17 into the lands as a fair compromise between 15 and 20.
Next I wanted to see how wide the powder charge window was so I loaded 30.0, 30.2 and 30.4, 17 into the lands.
30.0 looked about like 29.9 did- out of tune with a lot of vertical. 30.2 was back in tune and 30.4 repeated nicely. I will try 30.5 just to see what happens. 30.2 17 in gave me zero es for three shots with a mv of 2948. Rarely have I had three shots with the exact same mv. Better still, they all went into a nice tight hole. 30.4 gave me an es of 3 and mv of 2972. A nice right group in the exact same place on the target as 30.2.
I tried a smaller neck bushing with 30.4. Hit the same place in the target but the group opened up a bit to about .19.
Last, I am having some problems with Alpha OCD brass but will not get into it until I hear back from Alpha.
