Redding die question

[eric1115]

Ok, so I have what is probably a dumb question, but I haven't been able to find an answer.

Why are the Redding Competition bushing neck dies cartridge specific? If the neck die isn't supposed to touch the shoulder, why does it matter what the body of the case is?

Obviously the body die needs to be cartridge specific, and a FL die needs to be, but what does a .243AI neck die do vs a straight .243? Is it just a matter of supporting the body to make sure the neck goes through the bushing straight and centered?

 

[Seabeeken]

Is it just a matter of supporting the body to make sure the neck goes through the bushing straight and centered?

Bingo. A Lee collet neck die would be a better option if you dont want the body sized but eventually the case will get so tight that closing the bolt will be an issue

 

[Mikecr]

I doubt it really needs to be cartridge specific. Same with a seating die. Just sufficient in clearances, as you suspect.
Bushings, while loose in the die, are as self-centering as seating bullets are.

 

[ShtrRdy]

I would guess that it has something to do with aligning the neck of the case with the bushing

 

[Coyote Shadow Tracker]

If you have an "AI cartridge" and only want to neck size with a bushing probably would not matter, but you still would need to get a FL sizer for your "AI" after a number of firings.
This is the same question as to why you need a special "AI Seater" die opposed to like stated a .243 win or a .243 win AI..
Is it that critical to have a Seating Die cut to the shoulder to seat the bullet???

I have asked this question to a major Custom Die Maker. for example, how much of a difference from the .338LM Micro Seater Die opposed to the .338LMAI Micro Seater Die? The .338LM Micro Seater Die cost is $157.69 + Tax and the .338LMAI Micro Die is $241.91+ Tax. They are same die unless they cut the seating die to a AI shoulder, but when seating a bullet it is measured from the CBTO. Extra charge of $84.22 + tax.
I know PRS shooters that have 6br, 6brai, 6dasher sizer dies and use a 6BR Seater for all three. Do Die Manufactures just charge you more for a "Custom" package and make your custom Sizer and then put a Standard(Micro) Seater in it????

 

[243winxb]

The Redding Competition Bushing Neck Sizer Die is similar in concept to the Competition Seating Die, the cartridge case is completely supported and aligned with the sizing bushing before the sizing process begins. As the sizing process starts, the cartridge case remains supported in the tightly chambered, sliding sleeve as it moves upward. The resizing bushing self-centers on the case neck. The decapping rod is maintained in precise alignment by using the internal parts of the die as a linear support much like that of a firing pin. Meanwhile, the micrometer adjustment of the bushing position delivers precise control to the desired amount of neck length to be sized.

The neck is the only part sized. I like the FL size S type bushing die.