New 21st Century Shooting Hydraulic Arbor Press
- Thread starter rxs0
- Start date
It’s a great idea and I too have thought of using the Snclair’s mandrel for this exact purpose in the past but did not find the right force sensor and settled on the K&M.
However, I do think that one potential advantage of the K&M/21th Century method has over the mandrel method is the fact that you are measuring seating force using the actual two components (bullet and case) involved in the actual firing. We have been talking about variance in bullet diameter in another thread and I would think that being able to include that in the measurement would be important?
However, I do think that one potential advantage of the K&M/21th Century method has over the mandrel method is the fact that you are measuring seating force using the actual two components (bullet and case) involved in the actual firing. We have been talking about variance in bullet diameter in another thread and I would think that being able to include that in the measurement would be important?
-Sinclair mandrels help to reduce loaded runout as measured off bullets. This because of straighter seating.
-The only lube I'll ever need is the carbon layer.
-I don't know that neck tension would be affected to a measurable degree by normal bullet variances. I suppose it's possible, never tested it myself.
My focus has been on necks, and getting them normalized.
With Wilson neck sizing I use machine bushings to adjust the length of sizing. This provides adjustment to seating forces from each neck, as seen with a cycle over my mandrel. I match every neck -before seating bullets.
Whether it would be beneficial to also monitor bullet seating? I don't know. I do know it would not work well with my seating method, which includes 90deg turns -twice. And in order to get a valid measure of force here, you have to reach a somewhat consistent seating velocity. Way easier with a hardened mandrel.
As mentioned, this is not a direct measure of actual tension(bullet grip). We're gonna need something pretty special to do that.
And I would rather see these copy companies working on new things, instead of polishing old things.
-The only lube I'll ever need is the carbon layer.
-I don't know that neck tension would be affected to a measurable degree by normal bullet variances. I suppose it's possible, never tested it myself.
My focus has been on necks, and getting them normalized.
With Wilson neck sizing I use machine bushings to adjust the length of sizing. This provides adjustment to seating forces from each neck, as seen with a cycle over my mandrel. I match every neck -before seating bullets.
Whether it would be beneficial to also monitor bullet seating? I don't know. I do know it would not work well with my seating method, which includes 90deg turns -twice. And in order to get a valid measure of force here, you have to reach a somewhat consistent seating velocity. Way easier with a hardened mandrel.
As mentioned, this is not a direct measure of actual tension(bullet grip). We're gonna need something pretty special to do that.
And I would rather see these copy companies working on new things, instead of polishing old things.
Sinclair got it right on mandrel sizes. Either the expander mandrel or turner mandrel leave the neck ~1thou under cal, with the turner mandrel being ~1/2thou smaller. You can get hardened turner mandrels from Sinclair(what I currently use).
The expander mandrels work fine also, they do slightly wear over time, but they're cheaper.
PMA may harden all of them, I don't know.
I don't measure on first expansion after neck sizing, this don't matter. I measure when the necks are ready to load & get em matching. Then I charge & seat bullets.
The expander mandrels work fine also, they do slightly wear over time, but they're cheaper.
PMA may harden all of them, I don't know.
I don't measure on first expansion after neck sizing, this don't matter. I measure when the necks are ready to load & get em matching. Then I charge & seat bullets.
John has asked me to post this data. It is the result of his preliminary testing that he conducted with Bowhunter. When viewing this data, there are some important things to keep in mind. First of all, we have observed ES’s considerably better than these but we did not record the supporting data and therefore will not publish the results or make the claims (at this time). This data was derived using “seconds brassâ€. It was not our best, precision prepared match brass. Second, as a reviewer of this data, you should not expect identical or even similar results. What we have learned is that seating pressure is a parameter just like charge weight or OAL. You must find the optimal configuration for YOUR rifle. It will likely be different even in the case of two nearly identical rifles. Finally, the best conclusions that can be made from this small “one-time†sample of data is this: Extreme Spread will be optimal at a given seating pressure. Consistency (in PSI) alone is not sufficient. In other words, you can have every bullet seated at the exact same PSI, but if it’s not the optimal PSI for your rifle, you will not see consistent results at the muzzle end (i.e. with a chronograph).
One additional note, this data implies that unless you don’t mind setting a lot of loaded rounds aside as rejects, you better be in strict control of the parameters that influence neck tension. A good consistent annealing process, neck turning, and neck sizing will dictate how successful you are at limiting rejects. Most of you know that 21st Century makes a neck turning lathe that is second to none. 21st Century also makes stainless steel arbors and a stainless steel, free floating mandrel/die combination. Both arbors and mandrels are available with a titanium nitride option for longer wear and smoother operation.
Please see the attached spreadsheet for the data.
One additional note, this data implies that unless you don’t mind setting a lot of loaded rounds aside as rejects, you better be in strict control of the parameters that influence neck tension. A good consistent annealing process, neck turning, and neck sizing will dictate how successful you are at limiting rejects. Most of you know that 21st Century makes a neck turning lathe that is second to none. 21st Century also makes stainless steel arbors and a stainless steel, free floating mandrel/die combination. Both arbors and mandrels are available with a titanium nitride option for longer wear and smoother operation.
Please see the attached spreadsheet for the data.
BoydAllen
Gold $$ Contributor
Thanks. This brings up an interesting question. For those who turn necks, if a neck is thin enough, eliminating the higher seating pressures, do we then just have to worry about getting enough? It may also help to explain why annealing has become important in long range. Softer necks are limited in the maximum seating force that can be developed. In the short range game, where necks are around .008 and bullet shank neck engagements tend to be short. I have come to view neck tension (the only handle I have on bullet pull) as being more of a minimum requirement, that once met, had little additional value.
Nice data, thanks for sharing.
I was looking at your data and a couple of things struck me. One is the ES is worst at the two highest seating pressure groups i.e. 46-55 and 56-80. What was more of a surprise to me is these two highest seating pressure groups also had five of the lowest MV rounds. A bit opposite to what I would have guessed but I am sure that there is good reasons for this, just have not figured it out yet – LOL!
I was looking at your data and a couple of things struck me. One is the ES is worst at the two highest seating pressure groups i.e. 46-55 and 56-80. What was more of a surprise to me is these two highest seating pressure groups also had five of the lowest MV rounds. A bit opposite to what I would have guessed but I am sure that there is good reasons for this, just have not figured it out yet – LOL!
Pretty much everything in precision responds well to 'minimal' because this also leads to minimal variance.
But as Donovan & 21st suggested, neck tension is also a tuning adjustment. Get the variance low, and adjust tension across the board for best results.
Boyd, tension is not pull. You can change neck friction to adjust 'pull', or seating forces, with no affect at all to MV.
Tension is grip(squeezing force from springback). When you change this, you see it, regardless of friction.
But as Donovan & 21st suggested, neck tension is also a tuning adjustment. Get the variance low, and adjust tension across the board for best results.
Boyd, tension is not pull. You can change neck friction to adjust 'pull', or seating forces, with no affect at all to MV.
Tension is grip(squeezing force from springback). When you change this, you see it, regardless of friction.
something I would be interested in is seating depth variation due to more/less pressure needed to seat the bullet. I think this is the one measurement that would have been great to have right alongside the FPS, this coupled with an understanding of the bullets jumping or jammed would build a great picture.
6BRinNZ, our seating depth was a constant in this test. Variances of any parameters other than the one you are evaluating (i.e. seating pressure in this case) will make the results difficult if not impossible to interpret. I think it's pretty well accepted that when testing, you alter only one parameter at a time. Additionally, our seating depth is of no more consequence to you than would be our brass type, powder type, charge weight, etc. You need to determine what seating depth performs in your rifle and it will have no correlation to what performs in our rifle(s).
[br]dmoran said:
Unfortunately, not even close to addressing 6BRinNZ's comment. He was referring to seating depth variation caused by more or less seating effort. That would have required sorting bullets using Bob Green's tool, measuring each round and correlating it to seating effort. There is seating depth variation related to seating force. It would have been interesting to see it measured. In this case, it would simply be an artifact of the test and already occurring, so would not have added an additional parameter.
Recall that in my initial post I stated we used "seconds brass", not match grade. What that means is, we didn't weigh cases or water test them for capacity. Some were on their second firing after annealing, some on their third. We also did not uniform bullet tips, sort by weight, base to ogive or bearing surface. Variances in any one of these parameters will sufficiently hide any discernable effect (if it even exists) on FPS by a sub .001" variance in seating depth.
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