6.5 CM headspace issue

[G38xOC]

I was trying to figure out why my own reload wouldn’t chamber . I was full length sizing with foster die and shoulder would not bump .

Headspace using new brass @ 1.556 bolt closes fine
Headspaces using fired brass ( not out of rifle ) Fl sized , trimmed @ 1.563 bolt won’t close

I grind down shell holder 0.020” ( compared with new spare ) and check head space @ 1.555”

The FL die out of spec ? It was purchased back in 2018

Even if Redding competition shell holder only goes 0.10” max , right ? Still would have same issue .

Has anyone had issues with foster dies as well ?

[baih777]

Adjust your die. Additional turn 1/16th of.a turn.

[fguffey]

My cases do not have headspace. If you lower the deck height of a shell holder .020" and then use it to size a case to minimum length you will reduce the length of the case from the datum to the case head at least .020".

Someone will have to determine the length of the chamber from the datum to the bolt face, your short shell holder should give you 'lots of clearance'.

I have never screwed up a die by grinding/reducing the deck height, there are other ways to accomplish better results.

If I had your problems, I would purchase a new, over the counter, factory box of ammo.

F. Guffey

[fguffey]

Adjust your die. Additional turn 1/16th of a turn.

A reloader, when full length sizing will adjust the die down to the shell holder with an additional 1/4 turn. The additional 1/4 turn after contact increases the presses' ability to overcome the cases' ability to resist sizing.

1/4 turn equals .017" plus a little. 1/16th of a turn equals .004.3" plus a little.

F. Guffey

[pacrat]

https://saami.org/wp-content/uploads/2019/02/ANSI-SAAMI-Z299.4-CFR-Approved-2015-12-14-Posting-Copy.pdf

1.551"-MAX to 1.541"-MIN is the chamber HS spec according to SAAMI.

I have on several occasions in the last 54 yrs. Seen where FL sizing dies have been machined overly deep.

I grind down shell holder 0.020” ( compared with new spare ) and check head space @ 1.555”

Options are to turn down the face of die opening incrementally to bring it in spec.

Or contact Forester.

[G38xOC]

I was trying to remember I got the brass . Should've labeled it . It sure wasn't fired out the my tikka . Then again , FL die is gona do what it supposed to and if it's set right , out come should be the same regardless where the brass came from .

I do have some 6.5 creedmoor American gunner that I have shooting and saving brass . I will process them and compare the difference .

[G38xOC]

I have measure HS with hornady tool at each points with non modified shell holder

1/4 turn -- @ 1.563 bolt wont close
3/4 turn -- @ 1.560 still won't close
1 full turn -- @ 1.560

Shaved shell holder once --- 1.558 won't close
Shaved lil more at 0.020. --- 1.555 close nicely

I emailed foster tho . Interested I'm what they have to say

[G38xOC]

I just tried sizing fired brass from my own rifle using non modified shell holder and I only had to turn in 1/2 to get it chambered .

I guess the problem is the fired brass that I purchases . Maybe shot out of gas rifle or something?

2nd , would be safe to resize those brass with modified shell holder get it sized , then shoot em to reform to my chamber ?

[fguffey]

I guess the problem is the fired brass that I purchases . Maybe shot out of gas rifle or something?

I do not know what it would be like to not know how to determine if my press, die and shell holder failed to return the case to minimum length when sized. A reloader should be able to determine if the case was sized before he lowered the ram.

F. Guffey

[fguffey]

Options are to turn down the face of die opening incrementally to bring it in spec.

I have never shortened the length of a die, but if I did, I would determine 'by how much' first.

F. Guffey

[fguffey]

I have 12 Herter presses, all of my Herter presses are cam-over presses, because my Herter presses are cam over press all of them will bump twice, once on the way up and once on the way does. I have got 3 Rock Chuckers, none of my Rock Chuckers cam-over, meaning they are not bump presses.

I was full length sizing with foster die and shoulder would not bump

I find it impossible to move the shoulder back, I also find it impossible to bump the shoulder back, the only direction the shoulders move is forward. Another problem reloaders have with sizing a case, the shoulder they finish with is not the same shoulder they started with.

F. Guffey

[fguffey]

I just tried sizing fired brass from my own rifle using non modified shell holder and I only had to turn in 1/2 to get it chambered.

So, you raised the ram to the top of its travel and then screwed the die in until the die contacted the deck of the shell holder. After the die contacted the shell holder you gave the die an additional 1/2 turn?

The additional 1/2 turn lowered the die .0355". I have a feeling that means nothing to anyone involved in this thread but the .020" you removed from the deck of your 'modified' shell holder increased the presses' ability to reduce the length of the case from the datum to the case head.

F. Guffey

[FLIGHT762]

Even if Redding competition shell holder only goes 0.10” max , right ? Still would have same issue .

Redding competition shell holders make your shoulder bump LONGER not shorter.

A lot of reloader that don't actually use the Competition shell holders don't understand how they work.


I had a Mighty Armory 308 die that had the same issue you're experiencing. I was able to send the die back to them. They faced off about .008" off of the bottom of the die. They sent it back and it now works perfectly.

There are NO shell holders from a manufacturer that will shorten your shoulder. The manufacturers don't want to be responsible for a shell holder made out side of SAAMI spec. That's why you have to shave off a regular shell holder yourself.

[fguffey]

A lot of reloader that don't actually use the Competition shell holders don't understand how they work.

I could say the competition shell holder was developed after most reloaders discovered reloading. I could but we all should know the instructions come with the shell holder set.

Before the competition shell holder? There could have been 2 reloaders that used a feeler gage to adjust the die off of the shell holder. I still do, I have a M1917 that has a long chamber. The chamber is .002" longer than a field reject length chamber. For the reloader that understands what that means; the chamber from the shoulder to the bolt face is .016" longer than a minimum length/full length sized case from the datum to the bolt face.

What does that mean? It means I form 280 Remington cases to 30/06 cases by adjusting the die off the shell holder .014" to acquire a .002" clearance between the shoulder of the case and shoulder of the chamber.

My favorite shell holder is the RCBS shell holder, it fits the case like my old hand-me-down shirts, it fits where it touches. I use the loose fit of the shell holder to size cases for short chamber etc.

F. Guffey

[fguffey]

That's why you have to shave off a regular shell holder yourself.

I had rather know how to determine 'how much to grind' first. With 'nice to know stuff' I believe it would be nice if he knew how to measure the deck height of the shell holder. I have never shortened the deck height of a shell holder; I have never ground the bottom of a die to increase its ability to shorten a case from the datum to the case head, but JIC as in 'just in case' I have a perfect tool for that purpose.

F. Guffey