Lee Collet Neck Die question or any neck sizing die

[280shooter]

Ok here is my question and questions,, I load 8mm. 280.. and 223,, The 223 brass I have is from,spent cases from others, mine and new,,I have lots and lots of 223 brass from my auto. and bolt rifle, Now if the case was not shot from my Bolt action,, Do i use the FL die first, then shoot the loaded round in my bolt gun,, then use the collet die after that for my bolt gun,,
My 8 mm, i noticed it starting to have splits and cracks at the neck and I had to take the resizing die apart, because the necks broke apart,,Am I to late for the neck sizing die for my 8 mm,,?
I have new brass and some older brase for the 280.. the older brass I would say was loaded 4 times,,And the price for new brass, I would like to keep as much as I can,,
I just trimed 300 223 cases,, and that gets old fast,,would neck sizing retard the need to trim ?

 

[kingmt]

I think your saying you have a bolt gun in 223. If it were me I would pick a headstamp for the bolt action & FL all the cases the first time then any new to you brass should be FL. Say you picked Hornady as your bolts brass after first fireing keep it to itself & NS only.

You probably already know to FL all your auto brass.

You can heat treat the top half of your brass to relieve stress but since I don't know much about it I will leave that for someone with knowage about it.

NS with the collet will cut down on trimming.

 

[Blue68f100]

If any of the ammo was not fired in your bolt guns you need to confirm they will chamber easily. If not they need the shoulder bumped back/ FL sized. You can neck size the brass that was shot in your bolt guns. But you need to keep up with the number of firings or check for head spacing before you size so yo know which one to do. Annealing brass is something you normally have to do with bottle neck brass to keep it soft. Once it gets hard it starts splinting like you are seeing. Google Brass Annealing to find the procedure. All that is required is a propane torch and a pan of water. I normally set my brass up on a brick that is setting in a bucket of water. Once the brass is to temp I just knock it off into the water.

NS will reduce the wear and tear on the brass. But is best when you only have 1 gun the same caliber. If you have 2 you need to determine which gun has the shortest head space and size to that one. Then you can add shims to set the die back for the other.

If your shooting an AR you may want to look at the RCBS X-Die. This die has a mandrel to restrict the brass from stretching. You only have to trim the brass once, -0.020" below max.