RCBS has a special a competion seating die , and a sizeing die at a reduced price.The sizing die both neck or full can use bushings , been at this a long while but never been exposed to bushings , can some one enlighten me?
Thank Bill

The bushings are available in .001" increments and are used to size the neck of the cartridge. Check out Wilson, Redding or RCBS web sites for more info.

Bushing dies let you control how much you want to size the neck (dia) and how much of the neck you want to size. They work best if the case neck has been neck turned to get the same neck wall thickness on all cases. Benchrest shooters use bushings, with neck turning, to control clearance in there tight neck chambers.Most all standard factory dies, full length and neck sizing, size the neck down way more than needed to hold the bullet, over working the brass and making the neck thinner with each loading (243win). The expander button does this as it opens the case back up to useable dia. The Redding bushing die type S Full lenght sizing die i use can decap the primer with or with out the expander giving you full control of how much you size the neck. You will find that a neck sized about 1/2 way down the neck will give better accuracy because the unsized part of the neck will expand to the chamber on firing , centering the round in the chamber, making for a more accurate round over all, bench or factory guns. If the bushing die must size down the neck more than .010", there can be a problem (see Redding website) Overall the dies may or may NOT make your gun more accurate, only way to know is try. My Redding bushing die does not size fully to the shoulder area. Before neck turning in my Lyman turner i must full length resize in a standard full lenght die so i can get a good cut all the way to the shoulder.

to add my .02 and say it another way
All that drag produced by expander button is the result of excessive sizing by the neck of the sizer die. When the neck is sized correctly you do not need the expander or much force to size the neck either.

To get the most out of a bushing die the neck should be turned to a uniform thickness, or as close as possible. If not the error in neck thickness is transmitted to the neck I.D. as the O.D. is basically right on. This is not a good thing.

The bullet expands the neck back to round.
The less the neck is sized the less off center it can get. Turned necks can help but they may not help much if you don't use a tight neck chamber.

The smallest groups of 10 or more shots I know of with 30 caliber rimless bottleneck cartridges have all been shot with full-length sized cases. The die's necks were lapped out to about .002-inch smaller than loaded round neck diameter which eliminates the need for an expander (neck-bending?) ball. And the fired case shoulders set back no more than .002-inch.

When the firing pin slams into the primer, that force centers the front of the case in the chamber as the shoulders of both make an ideal centering arrangement for the case in the front of the chamber. In fact, the case shoulder is set back a bit from impact before the round fires.

Sierra Bullets uses full-length sized cases to test their product line for accuracy. They get groups in the ones at 100 and 200 yards with a good batch of match bullets. And their hunting bullets shoot more accurate from full-length sized cases. They tried all sorts of neck only sizing techniques back in the 1950s but never got the accuracy attained with full-length sizing. More and more benchresters are switching over to full-length sizing these days.

Case life? No worries. Done correctly, you can get 50 to 100 full-power loads from a .308 Win. case.

I asked RCBS back in the early 1970's to make such a die, but they weren't interested 'cause they didn't think there was a market for it. Even though such dies were used by top scoring highpower rifle competitors to win matches and set records. They finally have one; it's a good die indeed.

When I started handloading in the 50's neck sizing was in. Lyman made most of the tools then and the Truline Jr. or whatever it was only had neck sizing dies. If you wanted to FL size something there was a non threaded die that the case was pushed into in your vise and then hammered out with a rod!

The talk then was that neck sizing was more accurate. Turns out it was not.

As for myself I started FL sizing anyway as it makes ammo that is not a problem two years later or at dawn as you head into the woods.

Most of the conventional FL sizing dies over size the cases neck and then require a button to size the inside of the neck. This overworks the brass and also requires an extra lubricating and cleaning operation along with more runout and case trimming.

With a bushing die you get an old fashioned expanding button but you also get a holder for the decaping pin that clears the inside of the neck so no lube is needed. This works out very well and saves time.

I was not the first to try FL bushing dies but I did do have a number of them now. Most of my early ones are Redding but I prefer RCBS and now they make them. My first RCBS FL bushing die is a 243 and it's superb.

quote:

Case life? No worries. Done correctly, you can get 50 to 100 full-power loads from a .308 Win. case.

I don't think so. Try it some time.
The primer pocket loosens from just the press fit of the primer. Cases necks and bodies crack from the expansion and resizing.

Puleeze! "talk then was neck sizing was more accurate. It is not....". Don't ever go to a benchrest rifle match and say that out loud. You will be laughed out of the county... Nobody shooting bolt action rifles from rest for sub-moa accuracy full length resizes cases anymore, not since the 1970's.
FL sizing is for hunting rounds, neck for accuracy and target shooting. Go to www.benchrestcentral.com and catch up the last forty years of rifle accuracy development.

Rich

Rich, You should get your facts straight. Just about EVERY BR shooter FL sizes every time they reload. We use custom matched FL dies to the chamber, and size every time. Neck sizing went some time ago.

I agree with rws. Every BR shooter, that I know, except Vince Pastorella, full length sizes. The dies, however, are not your "run of the mill" dies. A good "bump" die uses a bushing to control neck sizing, but also is cut with a special reamer that was ground to be .001" smaller at the base than the finish reamer. This die is then adjusted to "bump" the shoulder back .001"-.002" while only sizing the body .001".