Redding Competition Bushing Neck Sizing Die

[TxCigarMadCap]

I acquired a set of Redding Competition Bushing Neck Sizing Die, Competition Seating Die and Body Sizing Die. I have always used the basic full length sizing die and seater die for all my hunting calibers. I understand stand the body sizing die acts a full sizing die minus the neck?

What I do not fully understand is the advantage in neck sizing the full length of the neck or just 1/2 or 1/3 of the neck? Or am I completely off in my understanding?

Thanks in advance for the help

 

[243winxb]

The body die is said to act like a FL die,minus the neck . Sizing 1/2 of the neck lets the unsized part of the neck expand to the chamber, centering the neck/round in the chamber. Works, i would guess, only with a FL sized case? I use the Type-S FL bushing die for 243 win. If i size more of the neck, accuracy drops off. Rem. 40X single shot rifle. Testing is the only way to know.

 

[jlow]

It’s an interesting question.

I think one of the advantage of sizing only part of the neck with a bushing die is you absolutely control the bearing surface length of the neck that contacts the bullet bearing surface. That surface length is affected by how far down the bushing goes down the neck and the OAL of the case.

One would think that the same would be true if you bump the shoulders down consistently and trim the case so that the OAL is consistent but there could be slight differences in where the neck shoulder junctions are?

Having a consistent bearing surface length allows you to better control the part of neck tension which is contributed by contact surface area between the neck and the bullet.

 

[TxCigarMadCap]

The idea is to size slightly more of the neck than the bullet is seated.

So if the shank of the bullet is seated into the shoulder area then you want the entire neck sized? I am trying to understand, I am not familiar with some of the more technical aspects of reloading. My reloading experience up to this point has been basic hunting reloads. I use a bullet comparator to measure ogive off the rifling but that's about the extent of my technical knowledge. So you are dealing with a very green newb.

I want to thank you for your input. I learn from every post. Well some of them, when I understand what's being explained!

 

[jonbearman]

No dont size the whole neck,leave about a quarter of it in the fired condition to center the acrtidge once it is chambered.I do this even when I am slightly into the shoulder area.By the way you can do this with a regular neck sizer with a busing or a full length type s die.You dont need to sping for the micrometer as it adds significant cost to the die.

 

[TxCigarMadCap]

No dont size the whole neck,leave about a quarter of it in the fired condition to center the acrtidge once it is chambered.I do this even when I am slightly into the shoulder area.By the way you can do this with a regular neck sizer with a busing or a full length type s die.You dont need to sping for the micrometer as it adds significant cost to the die.

Well the dies come with a rifle I purchased so I got out of the expense. So with a no turn neck chamber you are leaving a 1/4 unsized to center the cartridge? That makes sense if I am understanding you correctly.