sizing die

[Clem Bronkoski]

I'm assuming this is normal. I took some once fired Petersen cases that were fired from my rifle and (the 300WM) and they chambered easily. I ran my FL sizing die into my press until it contacted the shell holder then backed it out 2 full turns.
I checked a couple cases in my Hornady comparator and set the caliper to zero. After running the cases into the sizing die I rechecked the cases and the shoulder was pushed forward .002". (every one) The cases still chamber easily in the rifle. I'm assuming this is normal because the brass has to go somewhere - right?
I guess I'll continue to do the same until my cases reach a point where the fired ones do not chamber then go about resetting my sizing die for the .002" shoulder bump. Is that the correct thinking?

 

[Jester896]

the datum area in the die did not contact the datum area of the case if the sized brass is .002 longer after sizing. That would be expected if you backed it out that far. If it wasn't a belted case the bolt may not have closed on the sized round. It sounds like it didn't hurt you if they still chamber.

 

[WV Hitman]

I was told by Brian & JD Jones, owner of SSK Firearms to size my bottleneck cases with just a little light between the shell holder & die. Has worked great for 45 years. Never any case problems.

 

[Seabeeken]

the datum area in the die did not contact the datum area of the case if the sized brass is .002 longer after sizing. That would be expected if you backed it out that far. If it wasn't a belted case the bolt may not have closed on the sized round. It sounds like it didn't hurt you if they still chamber.

^^^^ right there it is.

 

[Clem Bronkoski]

the datum area in the die did not contact the datum area of the case if the sized brass is .002 longer after sizing. That would be expected if you backed it out that far. If it wasn't a belted case the bolt may not have closed on the sized round. It sounds like it didn't hurt you if they still chamber.

That's exactly what I was planning on. Next firing should be a better fit to the chamber. Then I'll readjust the die for the .002" shoulder bump if necessary.

 

[cdherman]

I'm assuming this is normal. I took some once fired Petersen cases that were fired from my rifle and (the 300WM) and they chambered easily. I ran my FL sizing die into my press until it contacted the shell holder then backed it out 2 full turns.
I checked a couple cases in my Hornady comparator and set the caliper to zero. After running the cases into the sizing die I rechecked the cases and the shoulder was pushed forward .002". (every one) The cases still chamber easily in the rifle. I'm assuming this is normal because the brass has to go somewhere - right?
I guess I'll continue to do the same until my cases reach a point where the fired ones do not chamber then go about resetting my sizing die for the .002" shoulder bump. Is that the correct thinking?

Not clear if you sized the case at all, you backed the die out like 0.142" so quite a lot.. -- are you using resizing die with an expander ball? The expander will "pull" the case longer at the shoulder sometimes. So you can resize the case, mostly the body and the neck and be surprised that the base to shoulder is longer. That is because the expander ball, on exit, pulled the shoulder out a bit.

Hope this makes sense....

 

[Clem Bronkoski]

Herman that's what I wanted to do. Basically just size the neck but I also sized most of the body and stayed off the shoulder until it's fully fire formed to my chamber. The design of the die and the way I currently have it set does resize most of the case body and the neck but doesn't touch the shouler. So what I'm surmising is that the brass has to move somewhere and takes the path of least resistance and moves forward.

 

[cdherman]

Herman that's what I wanted to do. Basically just size the neck but I also sized most of the body and stayed off the shoulder until it's fully fire formed to my chamber. The design of the die and the way I currently have it set does resize most of the case body and the neck but doesn't touch the shouler. So what I'm surmising is that the brass has to move somewhere and takes the path of least resistance and moves forward.

I follow your logic -- that resizing the body of the brass has to go "somewhere". I have not really seen cases get longer in that fashion. If you are willing to experiment -- take the expander ball out and see if you are still getting longer cases. In my experience its the expander ball that "pulls" the shoulder out.

Want to keep it shorter? decap with a decapping die, resize with a FL die not touching shoulder, but most of neck, w/o expander. Then use a mandrel to bring it to ready to load. I know. More steps. How much accuracy you want?

 

[Clem Bronkoski]

Herman I'll try that next time but right now all my brass is sized, primed and ready to load. I'll have some tomorrow after I run a seating depth test.

 

[243winxb]

backed it out 2 full turns.

Called neck sizing. One day, the loaded rounds will not chamber. Bad idea.

 

[Mikecr]

Instead of using rules of thumb, you should be setting your sizing die to produce the correct sizing.
That means full fire forming (without body sizing), 2-3 shots usually, THEN set the die for correct shoulder bumping to YOUR chamber.
Capture that die setting.

Many body sizing/FL dies squeeze down on body taper so much that they initially push shoulders forward at first,, and then continued inward case travel allows the die to reset the shoulders back. You will likely need to screw the die in more, until shoulders are measuring correct.
It really demonstrates how standard FL sizing excessively moves brass all over the place. NOTHING 'good' about it

 

[Clem Bronkoski]

Called neck sizing. One day, the loaded rounds will not chamber. Bad idea.

That's what I'm counting on so that I can size to just bump the shoulder back to allow for easy chambering. I just need to fire them another time or two until they won't go back in. What I am doing is not neck sizing but more accurately called partial sizing. Neck sizing is using a die that only resizes the neck and not the case body and there are dies made specifically for that purpose.

 

[QuietTexan]

You've landed on the best way to set up a die.... because there's no such thing as "bumping" a once fired case. You have to let it grow until it fits the chamber, THEN you bump it back. "Bumping" too soon is just overworking the brass. Mike and I are always saying this.

Called neck sizing. One day, the loaded rounds will not chamber. Bad idea.

This generalization is your opinion, and I vehemently disagree with it. I consider it to be the best idea to achieve stable brass that is not over-worked.

If someone is neck-sizing and not fitting the brass to the chamber before completing a loaded round, then their process needs improving because they're skipping steps. That doesn't make the concept invalid.

What's you're saying is analogous to "feel free to excessively trim your brass, because if you don't one day the brass will be too long and cause a problem."

 

[Clem Bronkoski]

Instead of using rules of thumb, you should be setting your sizing die to produce the correct sizing.
That means full fire forming (without body sizing), 2-3 shots usually, THEN set the die for correct shoulder bumping to YOUR chamber.
Capture that die setting.

Mike that is what I am trying to achieve. But I have to run the case into the FL die somewhat to size the neck otherwise I will have insufficient (or no) neck tension for the bullet.