i'v been using redding bushings in their competition dies for many years and recently bought a 22 BR type s fl bushing die. the decapping stem has an expander ball that is pulled out the neck after being sized by the bushing that will give me .002 neck tension after bullet seating. i'v not used it since the bushing is sizing the neck as stated. what is the purpose of benefit of this expander? i can only surmise the internal expansion uniforms the inside of the neck, being brass is a bit thicker as one goes down the neck. will this improve anything? if there is a benefit does one use a smaller bushing and allow the expander ball to "uniform" the internal neck? thanks.
the expander ball in a redding type s fl bushing die?
- Thread starter lpreddick
- Start date
jonbearman
I live in new york state,how unfortunate !
Stick with the bushing minus the expander . The expander is really not necessary as you already sized the neck properly with the bushing providing it is giving the exact tension you want to run.I don't know why they bother shipping the expander anymore really!
Dusty Stevens
Shiner
Boyd is right. It also makes the mouth round incase theyre dented
The critical final product is a neck that has a consistent internal diameter.
If you do a perfect job of turning your neck, then the bushing will reduce the external diameter giving you a reproducible and consistent internal diameter, and neck tension.
If your brass is not turned and of uneven neck thickness and you only use the bushing, your internal neck diameter and neck tension will be inconsistent unless you use the expander.
If you do a perfect job of turning your neck, then the bushing will reduce the external diameter giving you a reproducible and consistent internal diameter, and neck tension.
If your brass is not turned and of uneven neck thickness and you only use the bushing, your internal neck diameter and neck tension will be inconsistent unless you use the expander.
jonbearman
I live in new york state,how unfortunate !
You learn something new as far as giving advice.If it were fired brass it would likely be better without unless it pushes the indiscrepency inside without an expander. Boyd do you polish yours down for light contact or leave them as the factory made them.
I use the expander ball in all my dies. Turned or no turn. As others have said, its the inside of your brass that has to be correct. The only way to make sure your getting uniform neck tension is to expand out. If you think your turning your brass absolutly perfect every time piece to piece your kidding your self. And letting an outside diameter bushing determine the inside diameter of your brass is just plain wrong IMO.
That is only valid though if your trying to make accurate reloads. If you dont care then throw away that useless ball.
That is only valid though if your trying to make accurate reloads. If you dont care then throw away that useless ball.
So the reality is yes, you cannot turn necks that are absolutely the same but really pretty close, down in the 2-3 ten thousands.
However, if anyone thinks that their brass is going to size down exactly the same because they use the same bushing or the same expander ball, then they are also going to be surprised since sizing is always affected by the degree of work hardening of the brass and no two pieces of brass have exactly the same degree of work hardening so they will spring back slightly differently.
However, if anyone thinks that their brass is going to size down exactly the same because they use the same bushing or the same expander ball, then they are also going to be surprised since sizing is always affected by the degree of work hardening of the brass and no two pieces of brass have exactly the same degree of work hardening so they will spring back slightly differently.
I was always lead to believe that an expansion ball was never lined up with the center axis of the case. I don’t have a run out gauge. The ball is hung on threads about 1.5†from the neck. The more force used to pull the ball through the neck the worse it will be if the ball is off center. How do you line the ball up within 0.001†of the cartridge centerline? You adjust the die to get 0.001†shoulder bump then jerk the ball through the neck? The ball may make the I.D. more uniform but does it pull the neck off center and pull the shoulder forward. It’s the least accurately aligned part in the whole system. I use the bullet in a straight line seater as my expander ball, it’s formed to a tolerance of a few ten thou.
Someone in a reply stated that his 223 brass was used a lot and had more neck tension than he wanted. He solved the problem by expanding the necks with a ball. This should increase the neck tension, not reduce it. Expanding the neck then sizing it back down in a die is just additional cold working. The only way to reduce neck tension on highly worked/used brass is to anneal it.
Perhaps the reason you get an expander ball with the bushing die is because it gives you a depriming pin holder? Running the neck through a bushing then pulling the ball of some diameter through the neck doesn’t make sense. When I got my 6BR I bought a std fl die. Later I bought a bushing FL die. I lowered the depriming rod in my std FL die and use it only for depriming. Then go to my bushing die.
Someone in a reply stated that his 223 brass was used a lot and had more neck tension than he wanted. He solved the problem by expanding the necks with a ball. This should increase the neck tension, not reduce it. Expanding the neck then sizing it back down in a die is just additional cold working. The only way to reduce neck tension on highly worked/used brass is to anneal it.
Perhaps the reason you get an expander ball with the bushing die is because it gives you a depriming pin holder? Running the neck through a bushing then pulling the ball of some diameter through the neck doesn’t make sense. When I got my 6BR I bought a std fl die. Later I bought a bushing FL die. I lowered the depriming rod in my std FL die and use it only for depriming. Then go to my bushing die.
BoydAllen
Gold $$ Contributor
By the time that your case gets down to where the expander engages, it is no longer constrained by the die in any way, and to my way of thinking the case would simply pivot against the lip of the shell holder to allow the neck to center on the expander. I have done a lot of measuring of cases sized with slight expander "work" as compared with without, and my recommendation is not based on a guess. I have done it and measure the results several times. IMO the place where a decapping assembly being off center hurts you is as the case is being run into the die. It can hold the head of the case slightly off center as the neck enters the bushing. The reason that expanders have such a bad reputation is that in one piece dies the ID of the neck portion of the die is too small so that the expander has too much work to do causing axial tension that causes the case to yield asymmetrically at the shoulder, cocking the neck relative to the body CL.
Lapua40X
California Hunter Education Instructor
In search of the best concentricity possible I dump the neck sizing button and use a bushing that sizes necks where I want them. I finish up with an inside mandrel to make sure there's no irregularity when the case leaves the neck sizing die. The mandrel is sized .001 under bullet diameter so that if it contacts the neck walls at all it is so slight that overworking the brass is not an issue.
I also do not normally use the expander ball. I use a bushing that gives me .001 neck tension and then take a mandrel die and open up the neck to .0015 neck tension. I have been thinking about using the .001 bushing and trying to modify the expander ball to give me that .0015 or even .001 neck tension.
The explosion that takes place inside the chamber when a cartridge is ignited and which exerts anywhere from 40,000 to 60,000 PSI to the interior of a case's neck, will certainly iron out any imperfections that may have existed beforehand. Follow-on explosions are cumulative. To think that an expander ball is capable of facilitating an added benefit, is to ignore explosive blast physics. Custom F/L bushing die makers [Harrell's and Steven's dies come to mind] never include them. 
BoydAllen
Gold $$ Contributor
Unturned necks do not have their neck thickness runout improved by any number of firings. When unturned necks are inserted in the ID of a die or bushing, the irregularities in their thicknesses make their IDs irregular, and their shapes and dimensions inconsistent. This results in variation in the force that it takes to seat bullets, which is known to increase the extreme spread of velocities, which increases vertical dispersion, reducing overall accuracy. That dies which are made pretty much for the target shooting market, for use with turned necks do not have expanders says noting about their suitability for applications where necks are not turned. Have you loaded ammunition using cases with unturned necks using bushing dies?
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