30 Full Length vs. Neck only sizing

[Gun Geezer]

Ok. Next problem / concern with my 30-30 loading.

I have two 30-30s: Win 94 and a Marlin 336.

I have cases fired from both. Those fired in the 94 will easily slide all the way into the 336 chamber. But not vice versa. The 336 fired cases stick about 3/16 from the rim. Bummer.

I had hoped to only resize the neck as I understand case life will be longer that way. Since I'd prefer to have all ammo go in either rifle, apparently, this neck sizing only thing ain't going to work!

Am I missing something?

 

[rcmodel]

No.

Neck sizing doesn't work with more then one gun.

And neck sizing doesn't work with any lever-action.

Unlike bolt-actions, lever-actions like both of yours have rear locking bolts.

Resulting action springiness and headspacing on the rim will cause case stretch that has to be returned to normal by FL sizing.

rc

 

[Slamfire]

Your lever action does not have powerful cocking cams and in time, even those rounds that fit now after neck sizing, won't in the future.

Even though I have a 30-30 and have a cartridge case gage, I don't remember if the case gage measures off the shoulder. Regardless there are "comparators" that will measure fired case headspace dimensions and these will be relative to the chamber of the rifle.

Get one or the other and full length resize. Bump the shoulder back 0.003" from chamber dimensions. Your cases will chamber and last forever.

Bumping the shoulder back 0.006" will result in a short case life.

 

[Gun Geezer]

Your lever action does not have powerful cocking cams and in time, even those rounds that fit now after neck sizing, won't in the future.

Even though I have a 30-30 and have a cartridge case gage, I don't remember if the case gage measures off the shoulder. Regardless there are "comparators" that will measure fired case headspace dimensions and these will be relative to the chamber of the rifle.

Get one or the other and full length resize. Bump the shoulder back 0.003" from chamber dimensions. Your cases will chamber and last forever.

Bumping the shoulder back 0.006" will result in a short case life.

I am a total noob on rifle caliber reloading.

What do you mean "bump the shoulder back"?

 

[rcmodel]

Your case has a shoulder or step right behind the case neck holding the bullet.

That is called the case shoulder.

All rimless rifle calibers set headspace in the chamber based on the location of the shoulder.

Your rimmed 30-30 with factory ammo headspaces off the rim.

If you don't push the shoulder back where it started out, it can then headspace of the shoulder like a rimless cartridge.

That in turn keeps case stretch to a minimum, and extends case life so they don't stretch to the breaking point nearly as soon.

So, set the sizing die to just "bump the shoulder back" enough for easy chambering, but not clear back to the point it is headspacing off the rim again.

rc

 

[Slamfire]

I recommend using cartridge headspace gages for rimless rifles, been using a special one for my 375 H&H.

This is a 308 gage.


You size the brass so it is between the "Go" and "No Go" ledges of this gage.




Wilson shows a rimmed case gage. Makes me wonder whether shoulder length is controlled in the 30-30.

http://www.lewilson.com/images/CASE_GAGE.pdf

 

[murf]

only by partial full-length resizing, as per rc's post above. otherwise, headspace is controlled by the rim.

murf

 

[Walkalong]

Just don't push the shoulder too far back. That is where a case gauge comes in handy, or some way to measure where the shoulder is before firing, after firing, and after sizing.

It can be fancy and complicated, or simple, like the .300 Blackout shoulder bump gauge I made.