shoulder measurement on fired cases

[Bill Norris]

I have never seen a need to as far as seating bullets. What does the dwell time do for that ? Not bucking you just want to try and learn

I find it helps with consistency especially when seating in full cases where the bullet actually is touching the powder.

 

[6MMsteve]

I've never cammed my rockchucker....wouldn'd that stretch the threads on the die and put undo pressure on the casting and pins and mushroom the shellholder..maybe I'm wrong I don't know...if you need cam over for sizing then you need cam over for seating also...

 

[Homerange]

I've never cammed my rockchucker....wouldn'd that stretch the threads on the die and put undo pressure on the casting and pins and mushroom the shellholder..maybe I'm wrong I don't know...if you need cam over for sizing then you need cam over for seating also...

You are in charge of the die settings, no one else !
If you can't cam the press over lift the die until you just can.

 

[6MMsteve]

You are in charge of the die settings, no one else !
If you can't cam the press over lift the die until you just can.

I never had the need for camming, I may remove material from shellholder top but never cam, I don't really see the campoint..I guess some do some don't and some maybe, I am camming my 9mm a bit but I removed .040 from the shellholder and got my desired plunkster, with A smidge on camnation so I guess I lied on never cammington but it's moving the die bout .005. I put my trusty home dial up there on the side and it said .005 movment, but you can also remove .040 from the bottom of the size die and get the same results take out some of the chamfer and squeeze better

 

[rebs]

rebs, can you clarify whether you are asking about fired cases or about sized cases? Additionally, were they reloaded with less than full power loads?

asking about fired cases and sized cases

 

[6MMsteve]

I find it helps with consistency especially when seating in full cases where the bullet actually is touching the powder.

dwell time works wonders

 

[Kracken McGraw]

Guffy, whereeee are you!

 

[243winxb]

Redding Competition Shellholders are needed. Fl die & shell holder, needs to be making contact on sizing.

Light loads may make a fired case head to datum shorter, as the case body expands.

 

[searcher]

If you are taking your measurements on fired cases - I'd disregard the posts listing dies and such as being the culprit. The measurement differences are simply telling you that you have at least some cases that are at least .005" shy in length from fully blowing the shoulder forward. It is not uncommon to still have such discrepancies in length even after four firings when one or more of the following conditions is present:
1) You are bumping the shoulders before they are fully blown forward. You should measure a large number of your fired pieces and set your bump once you see there are a number of the LONGEST pieces the same approximate length. When your brass extends fully - it simply will go no further. This is the sign to watch for - and use that "MAX" length as your basis from where to bump.
2) You are shooting light loads. It can take forever to blow the shoulders forward on light loads.
3) You are shooting light bullets. They can take longer to get the shoulders forward - especially when using light powder loads light loads.

I'd measure all your fired pieces before sizing. Take the longest pieces and use that as your bump basis. Record that number before you size and fire again. After firing again, re-measure. If ANY of the pieces are longer than your last noted longest measurement - it tells you that your brass is still being set back prematurely. Just remember brass doesn't grow longer than your chamber. Good luck!