Case neck upsizing

[Far North Hunter]

I want to upsize one caliber my 260 Rem brass to allow me to partially neck down the neck just enough to force a tight cartridge base fit when chambered. The objective is to fire form the brass for 260 AI/improved.
Not wanting to crush the cases I'd appreciate your advice on expanders that have given you favorable results.

 

[dok7mm]

.284 is what I use, then start working my way down the neck with a bushing die. I like a fairly stiff closing on the bolt. The bushing should reduce the case neck to fit your chamber neck.

 

[Far North Hunter]

.284 is what I use, then start working my way down the neck with a bushing die. I like a fairly stiff closing on the bolt. The bushing should reduce the case neck to fit your chamber neck.

What brand of expander do you use, I'm sure it is a gradual taper to avoid crushing the case neck

 

[dok7mm]

Yes, it has a taper. I use K&M mandrels and use Imperial Wax on a Q-Tip to lightly lube inside the neck. You'll also need the threaded plug to hold the mandrel. Then adjust the mandrel plug in your press so that it sizes the full neck but does not hit the bottom of case. Very simple to use.

 

[GLTaylor]

If you are improving cases, simply seat your 264 bullets to engage the rifling, reduce your normal charge slightly and fire them. The bullet seated in the lands will hold the cartridge in place during the fire corming process. No need to expand the necks.

 

[Far North Hunter]

Yes, it has a taper. I use K&M mandrels and use Imperial Wax on a Q-Tip to lightly lube inside the neck. You'll also need the threaded plug to hold the mandrel. Then adjust the mandrel plug in your press so that it sizes the full neck but does not hit the bottom of case. Very simple to use.

That is just what I needed to hear. I new that a std expander mandrel was not going to work. Had seen 21st century has upsizing mandrels but hoped to get some input from someone with experience.
thank you

 

[DocDoc]

If the chamber was done correctly, .004 short of the parent case, there is no need to expand and downsize the neck or seat the bullet into the lands. A/I was designed to safely fire the parent. There should be a "little" resistance to closing the bolt on the parent.

You can also use pistol powder behind cream of wheat and tissue plug to fire form the case without a bullet.

 

[Deleted member 115654]

Use Zeglin method. No barrel wear.

 

[Far North Hunter]

If the chamber was done correctly, .004 short of the parent case, there is no need to expand and downsize the neck or seat the bullet into the lands. A/I was designed to safely fire the parent. There should be a "little" resistance to closing the bolt on the parent.

You can also use pistol powder behind cream of wheat and tissue plug to fire form the case without a bullet.

Very much the same advise given by Dave Manson's staff.