Would S type Bushing help in Lowering ES
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DUSTY NOGGIN
Well-Known Member
a bushing die will help with ES's
i prefer the bushing approach , with or without the expander , depending on how much sizing is being done , that has alot to do with the starting brass neck thickness , expander outside dimension , the inner dimension of the sizer die & , and how much its moving the brass on each operation
i think the bushing first to .001 under your intended diameter , which will leave stress in the brass/ spring back . if then opened up with the expander mandrel to your intended size , reduces the stress left from the bushing die and because the expander only sized a small amount , it would have not created very much spring back in the other direction , plus the remaining spring back will be in the same direction as when seating ( it will want to squeeze tighter ) -- this method also leaves you with the best run out possible IMO as long as your seating operation after doesnt create it
you could get away with just using a bushing without a die expander . but in that scenario id hope that all neck wall thickness's were very consistent ( turned ) and go with a slightly smaller bushing so when seating a bullet it basically will overcome that sized down stress/spring back , then basically use the bullet to expand it just past were where the neck wants to be relaxed ...
if you anneal after any way of sizing you go , itll create a very relaxed state of brass at your intended dimension , that is where that low ES happens IMO , especially if you add dry neck lube to that mix
the thicker the neck the more spring back memory you have
i prefer the bushing approach , with or without the expander , depending on how much sizing is being done , that has alot to do with the starting brass neck thickness , expander outside dimension , the inner dimension of the sizer die & , and how much its moving the brass on each operation
i think the bushing first to .001 under your intended diameter , which will leave stress in the brass/ spring back . if then opened up with the expander mandrel to your intended size , reduces the stress left from the bushing die and because the expander only sized a small amount , it would have not created very much spring back in the other direction , plus the remaining spring back will be in the same direction as when seating ( it will want to squeeze tighter ) -- this method also leaves you with the best run out possible IMO as long as your seating operation after doesnt create it
you could get away with just using a bushing without a die expander . but in that scenario id hope that all neck wall thickness's were very consistent ( turned ) and go with a slightly smaller bushing so when seating a bullet it basically will overcome that sized down stress/spring back , then basically use the bullet to expand it just past were where the neck wants to be relaxed ...
if you anneal after any way of sizing you go , itll create a very relaxed state of brass at your intended dimension , that is where that low ES happens IMO , especially if you add dry neck lube to that mix
the thicker the neck the more spring back memory you have
Last edited:
Mikecr
Well-Known Member
Low tension will reduce variance of it. But be sure to load develop with low tension (or any chosen tension), whether from annealing or minimal sizing.
Some cartridges & loads won't like it.
It seems often implied that frequent annealing is something you should do.
But sometimes it's just opposite of what you should do.
Some cartridges & loads won't like it.
It seems often implied that frequent annealing is something you should do.
But sometimes it's just opposite of what you should do.
Braunschweiger
Well-Known Member
my setup has been to use a bushing FL sizing die with the sizing button removed, then using sinclair Neck Turning mandrel die to size the Inside Diameter of the case neck. So you are saying that you use a normal NON-bushing style sizing die (Mighty armory FL sizing die for example) with everything pulled out so that it bumps the shoulder, then use the sinclair mandrel to size the neck? I may start doing that.
Mikecr
Well-Known Member
FL sizing of necks causes a range of neck tension from very high to extreme.
For sure it causes high tension variance.
This can be just what the doctor ordered for a tiny or underbore cartridge running competitive(extreme) pressures. Something like a 6PPC/30BR well into diminished returns(pressure-wise), which also equals diminished variance of returns.
But this is not viable with hunting capacity cartridges.
You might need a binding shelf in necks to prevent bullet setback with extreme recoil of ammo loaded in length limiting magazines.
A FL sized neck with bullet bearing seated deep has not only full area of neck spring back gripping all the bearing area, but also the unexpanded donut area (beneath bullet bearing) binding on the bearing base junction. If the bullet bearing is seated too close to, or in neck-shoulder junction, and you've FL sized the neck, then you've also added shoulder angle as a factor of neck expansion needed to release bullets.
None of this occurs with partially sized necks. The shoulders don't matter. The donut area thickness doesn't matter. The spring back area gripping bullets is precisely set by sizing length, and any deeper portion of seated bullets is clear of influence.
I can think of no down side to this (where appropriate to do it).
For sure it causes high tension variance.
This can be just what the doctor ordered for a tiny or underbore cartridge running competitive(extreme) pressures. Something like a 6PPC/30BR well into diminished returns(pressure-wise), which also equals diminished variance of returns.
But this is not viable with hunting capacity cartridges.
You might need a binding shelf in necks to prevent bullet setback with extreme recoil of ammo loaded in length limiting magazines.
A FL sized neck with bullet bearing seated deep has not only full area of neck spring back gripping all the bearing area, but also the unexpanded donut area (beneath bullet bearing) binding on the bearing base junction. If the bullet bearing is seated too close to, or in neck-shoulder junction, and you've FL sized the neck, then you've also added shoulder angle as a factor of neck expansion needed to release bullets.
None of this occurs with partially sized necks. The shoulders don't matter. The donut area thickness doesn't matter. The spring back area gripping bullets is precisely set by sizing length, and any deeper portion of seated bullets is clear of influence.
I can think of no down side to this (where appropriate to do it).
Yes sir as long as that brass isn't neck turned of coarse. Just FL non busing die with everything removed from inside bumping the shoulder and then run mandrel.
I accept the sincerity. As a long time skeet and NRA bullseye shooter time prevented my eyes from pursing those great sports. The scopes on rifles make up what sight failures I have and so I started shooting rifles. While I have reloaded for years for shooting sports rifles are new. Some questions may seem common to others they are indeed sincere to my learning. The bottom line my rifle now shoots extremely accurately with help from forum members.
