How much Brass spring back?

[P1ZombieKiller]

My general understanding is that brass has natural spring back in the neck.

If I wanted to expand a piece of brass wide enough for a .3084 bullet to EASILY slide in and out of it, what would I need to expand it too? .3090? .3095?

Let's assume .3090.... In order to expand that ID to .3090, would I need a .310 expander? .3105?

I have a .323 mandrel that I want to turn down to the right size to expand the necks enough for the spring back to still meet that .3090 requirement.

 

[lukehalee]

I have been told to figure about 1/2 a thou on new brass. I have done measuring, but don't have the correct equipment to verify that my busing are what the actually say they are. Hopefully someone that has actually measured with the correct equipment will chime in.

 

[P1ZombieKiller]

I suggest to turn it down on the big side and see on a couple cases. You can always turn or sand more off after the fact.

Good Luck !
Donovan

Would love too except I do not own a lathe so I have to send this out to be done. I'm trying not to have to send it out several times. I can turn the walls to what ever size I want AFTER I get the ID to allow a .3084 bullet to slide in and out easy.

I'm going to ASSUME that a .3095 ID neck will be fine, and ASSUME a .3105 mandrel will allow the spring back to stay on the + side of .3095

 

[Shynloco]

Spring back of case necks will be dependent on wall thickness, softness, and brands. I suggest to turn it down on the big side and see on a couple cases. You can always turn or sand more off after the fact.

Good Luck !
Donovan

P1ZommbieKiller,
Not trying to make this difficult, but since I use mandrels on all the calibers I reload for (I shoot strictly paper) I can say from experience that what Donovan says is very accurate. In taking those words further, the spring back also can vary depending on the caliber of casings you are using, even with Lapua brass which I use exclusively. Just something to consider.