Depending upon exactly what you wish to accomplish, the partial neck sizing and the little donut for me usually produce greater accuracy through the alignment of the bullet to the bore. You need simply to have enough "bullet pull" to have consistant ignition of the powder charge. One of the reasons that I often seat to have engagement with the rifling is this ignition issue. Bullet pull is mainly controled by the bushing size, preferably about .002 less than loaded round neck diameter. I have found the current crop of Redding tools to be the best for my shooting needs. Good luck There really is no specific length to size down the neck, though many would say at least one caliber, i.e., .25 inches or so... .2 would do I am sure.

I have recently aquired a set of Redding competition Dies in 25-06. The amount of neck the bushing dies resize is variable. Is there a recommended amount or optimum length of the neck which enhances accuracy or should I resize down to the base of the neck to avoid a donut? I am at present resizing all of the neck and accuracy is definately better with these dies than my old RCBS ones. Thanks AM

My goal is best accuracy in all my rifles. I wondered if there would be anything detrimental if I were to partailly size the neck, for example the length of the case that a particular bullets shank is in contact with. I do not want to end up with the chance of case failure if I size too little - if that is possible?

Thanks for the replies, I will try re-sizing 3/4 the length of the neck and see how that goes. At present I am obtaining sub 1/2" groups consistantly, usually two keyholing and another just off. I put that one down to my trigger pull technique!!
AM

Good advice above.

Redding says .002-.003 smaller than loaded round.
I have been playing with .0005 smaller on rounds that are seated .005 into the rifling.

I resize about 2/3 of the neck.
IIRC Redding mentions something to the effect that many loaders are gettng best results from sizing approx half of the neck.

Travis F.

BTW

I need to mention that the sizing I descrbed above ( .0005 ) is for single loaded bolt guns only.

Please use more neck tension for your semi auto stuff...

Travis F.

Andy, I had e mailed Butch Lambert of thebarrelman.com and he suggested that you measure the diameter of ammo that you loaded in the neck area and use a bushing that was .003 inches smaller. Example,if your loaded ammo measures .333 in diameter in the neck area, he said to use a bushing of .330 diameter. He also suggested using a carbide bushing to avoid having to use lube on the cases and to eliminate scratching the cases which happens if you don't use enough lube.