Toprudder
Member
I thought I would take a stab at neck turning, to see if there would be any significant improvements. I purchased the 21st century tool, and I went whole hog and got the carbide cutter and nitride coated mandrel. I also got the matching neck sizing mandrel and die to complete the set. (I have been very pleased with their products!).
My first bottleneck rifle loading was with 223, and that is where I have done the vast majority of my learning and experimentation. So, that is where I thought I would start with learning to neck turn. If anyone is wondering 'why waste the time on 223', it is because it is one of the less expensive rounds to experiment with, and if I waste some brass - so what. I will be able to transfer anything I learn now over to a more worthy cartridge later.
For this experiment, I matched the brass by weight (I know volume would be better) using twice fired LC. I also annealed all the brass. The sequence was as follows:
1) Decapped.
2) Wet tumbled 10 minutes (no pins).
3) Salt bath annealed.
4) Washed again (no pins) to remove any salt residue.
5) Neck sized with Lee collet neck sizer. (so neck would fit the turning mandrel).
6) Turned necks. I had the wall thickness set to ~ 0.011".
7) Lubed, full length sized, without expander
8) Expanded using 21st Century mandrel and die.
9) Wet tumbled, with pins, 1 hour.
10) Trim, chamfer and debur.
11) Matched by weight.
12) Loaded. No crimp.
I realize that it might be best to turn the necks AFTER full length sizing, trimming, etc., but my intent was to make a final product that would have the bullet completely concentric to the case body as possible, and I thought the best way to do that was to full length size AFTER the necks were turned and the neck walls were uniform. I welcome comments on this.
I also loaded an identical set, but left out steps 5 and 6. This would be the control group. Both groups were loaded at the same time to maintain consistency.
Loads were with 8208XBR powder, 22.7, 22.9, 23.1, and 23.3gn. Previously, 23.1 was my accuracy load. Hornady 75 BTHP Match.
Non-turned necks
22.7gn, 2661 fps, SD=13.9, ES=26.24.
22.9gn, 2689 fps, SD=16.0, ES=38.2.
23.1gn, 2712 fps, SD=8.4, ES=21.22.
23.3gn, 2754 fps, SD=15.1, ES=35.3.
Neck turned:
22.7gn, 2678 fps, SD=6.5, ES=18.4.
22.9gn, 2700 fps, SD=7.8, ES=19.8.
23.1gn, 2733 fps, SD=9.5, ES=23.4.
23.3gn, 2749 fps, SD=7.1, ES=18.3.
Interesting to note the consistency across the charge range with the neck-turned loads. The only one that was not better was the 23.1gn load, and the difference there was not statistically significant. I can only assume that the more consistent velocities were due to more consistent neck tension.
Shot from my 20" AR, all of the groups were 1.0" - 1.4", with the groups showing some horizontal spread that I would associate with the 10-15mph crosswind that was present, so I can't really say that any one group was any better than the others. The 23.3gn loads both showed the least amount of vertical spread, though, at about 0.5". With the turned brass showing less extreme spread, this could only translate to more accuracy at farther distances.
This was an eye opener for me. Prepping rifle brass is one of the least enjoyable parts of reloading for me, but seeing the benefits when proper attention is given during the process, it makes it a little more tolerable.
Comments welcome and encouraged.
My first bottleneck rifle loading was with 223, and that is where I have done the vast majority of my learning and experimentation. So, that is where I thought I would start with learning to neck turn. If anyone is wondering 'why waste the time on 223', it is because it is one of the less expensive rounds to experiment with, and if I waste some brass - so what. I will be able to transfer anything I learn now over to a more worthy cartridge later.
For this experiment, I matched the brass by weight (I know volume would be better) using twice fired LC. I also annealed all the brass. The sequence was as follows:
1) Decapped.
2) Wet tumbled 10 minutes (no pins).
3) Salt bath annealed.
4) Washed again (no pins) to remove any salt residue.
5) Neck sized with Lee collet neck sizer. (so neck would fit the turning mandrel).
6) Turned necks. I had the wall thickness set to ~ 0.011".
7) Lubed, full length sized, without expander
8) Expanded using 21st Century mandrel and die.
9) Wet tumbled, with pins, 1 hour.
10) Trim, chamfer and debur.
11) Matched by weight.
12) Loaded. No crimp.
I realize that it might be best to turn the necks AFTER full length sizing, trimming, etc., but my intent was to make a final product that would have the bullet completely concentric to the case body as possible, and I thought the best way to do that was to full length size AFTER the necks were turned and the neck walls were uniform. I welcome comments on this.
I also loaded an identical set, but left out steps 5 and 6. This would be the control group. Both groups were loaded at the same time to maintain consistency.
Loads were with 8208XBR powder, 22.7, 22.9, 23.1, and 23.3gn. Previously, 23.1 was my accuracy load. Hornady 75 BTHP Match.
Non-turned necks
22.7gn, 2661 fps, SD=13.9, ES=26.24.
22.9gn, 2689 fps, SD=16.0, ES=38.2.
23.1gn, 2712 fps, SD=8.4, ES=21.22.
23.3gn, 2754 fps, SD=15.1, ES=35.3.
Neck turned:
22.7gn, 2678 fps, SD=6.5, ES=18.4.
22.9gn, 2700 fps, SD=7.8, ES=19.8.
23.1gn, 2733 fps, SD=9.5, ES=23.4.
23.3gn, 2749 fps, SD=7.1, ES=18.3.
Interesting to note the consistency across the charge range with the neck-turned loads. The only one that was not better was the 23.1gn load, and the difference there was not statistically significant. I can only assume that the more consistent velocities were due to more consistent neck tension.
Shot from my 20" AR, all of the groups were 1.0" - 1.4", with the groups showing some horizontal spread that I would associate with the 10-15mph crosswind that was present, so I can't really say that any one group was any better than the others. The 23.3gn loads both showed the least amount of vertical spread, though, at about 0.5". With the turned brass showing less extreme spread, this could only translate to more accuracy at farther distances.
This was an eye opener for me. Prepping rifle brass is one of the least enjoyable parts of reloading for me, but seeing the benefits when proper attention is given during the process, it makes it a little more tolerable.
Comments welcome and encouraged.