dstoenner
Silver $$ Contributor
Thought I would show you my attempts at developing a load for the Berger 85.5. My gun is a Remington 700 that has a 223 Criterion Remage 1:8 heavy Palma profile at 26 inches long. When I started this series of shots I was at 1844 rounds down range on this barrel. The original chambering is a Wylde but the throat has advanced about .065 inches. The rifle is in a MDT LSS-XL chassis with a Golden Eagle scope. I shot all of these at a magnification of 40 due to being indoors.
At this point I loaded all of the bullets at 2.570 which is about .020 off the lands but also is the longest I would ever load this bullet placing the junction of the boat tail at the shoulder neck junction thereby giving full bearing surface contact.
I loaded 10 increments of Varget from 23.0 to 24.8 in .2 gn increments. I loaded 4 at each step, 3 to be used for a group and 1 to be used to pressure test how far I would go up. Our weather turned colder by the time I could get to the range, about 45 degrees. This was shot from a concrete bench indoors at 100 yards.
First up was the pressure test. I did this with my magnetospeed attached and when I saw where shot 1 landed I did no adjustments to the scope. I went through all 10 without any sign of over pressure. These bullets just really shoot. I thought the 80.5's were good but these seem to be even better.
Next were group testing. I started at 23.0 and walked all the way up. I then added 2 groups of my standard load of 80.5 for comparison purposes to finish out the day. I have recorded the average of each 3 shots and the SD for each group on the target. What got me was that some really wild SD's shot excellent groups while the last one with an SD of 8 looked more scattered. Go figure.
I personally see 2 nodes that I am going to test out, 23.7 ( with 24.6 and 24.8 as guard bands) and 24.4 as the widest node. I might also load some at 24.4 with increased jump to see how this bullet would do as the throat advances even more. I usually call a barrel done when the throat has advanced about .100 inches.
I will append to this my final testing as outlined in the previous paragraph unless anybody has better ideas. That is why I am sharing this data. Also at 2780 or so FPS, I only see this as a good 600 yard bullet, not 1000. The 223 is still pretty limiting as compared to even something like a 22 BR.
David
At this point I loaded all of the bullets at 2.570 which is about .020 off the lands but also is the longest I would ever load this bullet placing the junction of the boat tail at the shoulder neck junction thereby giving full bearing surface contact.
I loaded 10 increments of Varget from 23.0 to 24.8 in .2 gn increments. I loaded 4 at each step, 3 to be used for a group and 1 to be used to pressure test how far I would go up. Our weather turned colder by the time I could get to the range, about 45 degrees. This was shot from a concrete bench indoors at 100 yards.
First up was the pressure test. I did this with my magnetospeed attached and when I saw where shot 1 landed I did no adjustments to the scope. I went through all 10 without any sign of over pressure. These bullets just really shoot. I thought the 80.5's were good but these seem to be even better.
Next were group testing. I started at 23.0 and walked all the way up. I then added 2 groups of my standard load of 80.5 for comparison purposes to finish out the day. I have recorded the average of each 3 shots and the SD for each group on the target. What got me was that some really wild SD's shot excellent groups while the last one with an SD of 8 looked more scattered. Go figure.
I personally see 2 nodes that I am going to test out, 23.7 ( with 24.6 and 24.8 as guard bands) and 24.4 as the widest node. I might also load some at 24.4 with increased jump to see how this bullet would do as the throat advances even more. I usually call a barrel done when the throat has advanced about .100 inches.
I will append to this my final testing as outlined in the previous paragraph unless anybody has better ideas. That is why I am sharing this data. Also at 2780 or so FPS, I only see this as a good 600 yard bullet, not 1000. The 223 is still pretty limiting as compared to even something like a 22 BR.
David
. Good luck with it.
