NEED HELP

[Straight Shooter]

Need some help gentlemen. I am resizing some 6MM creedmoor cases and am having trouble which I have never had before. I can't get my shoulder bumped back far enough.And I have screwed my die all the way down. Never had this happen before. What am I doing wrong?

 

[Dmagna]

There are a few ways to solve this, number 1 is that you can resize as much as you can and if it chambers you are good. You can shave the shell holder. Try a different die.

 

[MagnumManiac]

If this is once fired brass, STOP!
There is no NEED to size once fired brass.

Cheers.

 

[Straight Shooter]

I am using the same shellholder that I have used for years. This is ADG brass on its 4th firing.

 

[Lefty7mmstw]

Did it make spec to start with? If so, I'd bet your lock-ring migrated on the sizing die a bit.
Been there, done that once or twice. I've gone to lock rings that clamp so they won't walk.
Btw, I fl size all my brass every time and It's been working fine for 3 decades for me. I don't care if I lose a firing of 2. My ammo fits the rifles right and the accuracy is good.

 

[jseandsje]

Don't bump until you feel significant resistance chambering a casing. Then .002.

If that's not it and you're already tight, get someone to mill .002 off the top of your shell holder. But first I'd adjust for to 1/4 past flush and really cam over - if you have that type of press.

My son's 270 wsm had the same problem. The extra cam over in a Rockchucker Supreme solved that problem.

 

[jseandsje]

I am using the same shellholder that I have used for years. This is ADG brass on its 4th firing.

Do you anneal? Possible overanneal?

Using an expander ball type die? If so do you lube inside case necks? If not, and soft brass, could be lifting shoulder when re/expanding necks.

 

[KNOTFERSAIL]

Take a strip of paper 1/4" ish wide, fold it over itself two (or three if you need more bump) times and slide in the shell holder, lube inside of case neck, put brass in shell holder on top of paper and run through the size die. Measure the shoulder and see if it will chamber, if all good "polish" a couple thousands of top of shell holder. I use 600 grit paper and water..kinda of a wet sand . Doesn't take long to remove a few thousands

 

[MagnumManiac]

Forget all the BS, do you have a head space comparator?
If you don't, get one.
Guessing is a futile exercise.
If you have started FL sizing from the get-go without knowing your fired dimension first, you are probably already bumping too far without knowing it and the die is just bringing it back to that dimension.

Cheers.

 

[Straight Shooter]

Have been using the comparator and I can screw the die down far enough so there is no cam over and it still doesn't bump the shoulder enough.

 

[MagnumManiac]

Why no cam over?
This is how you get the case sized, without it, the slop in the linkages doesn't allow the case to enter the die fully.
If you size a case and can see a gap between the case head and shellholder, this is your answer as to why the case is not sizing.
To overcome this, place a .003" feeler gauge UNDER the case head, size and check, if no difference, use a .001" thicker feeler gauge until you get bump, then use the correct feeler gauge thickness to bump the correct amount. Remove the decapping stem if doing this.
If the die is short, turn .010" off the top of the shellholder and adjust the die as normal until you bump.
Again, I recommend camming over, it is far more accurate than not doing so.

Cheers.

 

[Straight Shooter]

The reason it is not camming over is because I have the die screwed in so far.

 

[MagnumManiac]

The reason it is not camming over is because I have the die screwed in so far.

Sorry, this makes zero sense.
I will just move on.

Cheers.

 

[CogburnR]

Have been using the comparator and I can screw the die down far enough so there is no cam over and it still doesn't bump the shoulder enough.

How does a resized case measure compared to a fired case? That is what you need to know. As mentioned there are a number of ways to deal with this and this is why Redding makes competition shellholder sets. I've seen dies from different manufacturers be close to .015" different(that is a LARGE amount). I've ground shellholders, welded up shellholders , ground the bottom off dies and bought different dies for this issue.