Shoulder bump headspace

[Brad615]

Hello,
I'm having an issue with shoulder bump/adjusting my headspace & hoping somebody can help. I use redding competition dies (FL sizing die & micrometer seating die) with redding competition shell holders & RCBS shell holder. So I resized my brass & noticed my shoulder bump was not adjusting to the 2 thou under that I'm looking for. I have moved my die to both cam over, to just touching, to off the die slightly. I used every redding shellholder as well as rcbs shellholder & it will not adjust up towards the 2 thou under my fired brass measurement. In fact it only keeps moving it the opposite direction (10-15 thou under my fired brass) I did use the same piece of brass with each shell holder & die adjustment. Could it be that I'm using the same piece of brass? Something I'm doing wrong? Problem with my die? Any help would be appreciated. Thank you.

 

[cajun]

Back the die out if its over sizing your brass.

 

[cajun]

When I size brass for the first time I adjust so it touches the shell holder then back it off 1/2-3/4 turn. Size then measure. Some dies have to be adjusted to max came over some way off. Just depends on your chamber and the die tolerances.

 

[cajun]

Also once you over size a piece of brass its not going to get smaller head space.

 

[Brad615]

Thank you

 

[jimbires]

if you are using once fired brass this is your problem , it's not fully expanded . take 3 or 4 pieces of brass and fire them . then neck size only , reload , and fire them again . do this until the brass gets tight to chamber , it usually takes 3 or 4 reload cycles . when you get the brass fully expanded , now you can set up your die to bump the shoulder . use good case lube , and have the die adjusted to make firm contact , or cam over with the competition shellholder . start with the +.010 shellholder size a piece of brass and measure . if the length stayed the same , or got longer go to the +.008 . measure the brass , if it stayed the same or got longer go to the +.006 . keep doing this until you get the brass .002 shorter . it is normal for the case length to get longer during the first few shellholder steps . as mentioned above , if you over size the brass it's to short now , until it's fired again . grab another one of the fully expanded ones and work with it .

 

[Brad615]

if you are using once fired brass this is your problem , it's not fully expanded . take 3 or 4 pieces of brass and fire them . then neck size only , reload , and fire them again . do this until the brass gets tight to chamber , it usually takes 3 or 4 reload cycles . when you get the brass fully expanded , now you can set up your die to bump the shoulder . use good case lube , and have the die adjusted to make firm contact , or cam over with the competition shellholder . start with the +.010 shellholder size a piece of brass and measure . if the length stayed the same , or got longer go to the +.008 . measure the brass , if it stayed the same or got longer go to the +.006 . keep doing this until you get the brass .002 shorter . it is normal for the case length to get longer during the first few shellholder steps . as mentioned above , if you over size the brass it's to short now , until it's fired again . grab another one of the fully expanded ones and work with it .

Thank you for the reply. The brass I'm working with was cycled 4-5 times (FL) I'm going to shoot them again as I already loaded up more & when I re-size them again I will do what you suggested. Thanks again

 

[WapitiBob]

I have never gotten a .002 shoulder bump with the die hitting the shell holder; rcbs dies, redding competion dies, and redding comp shell holders. I'm backed off about .010"

 

[Tac-O]

. I used every redding shellholder as well as rcbs shellholder & it will not adjust up towards the 2 thou under my fired brass measurement. In fact it only keeps moving it the opposite direction (10-15 thou under my fired brass) I did use the same piece of brass with each shell holder & die adjustment

I'm confused here. When you're trying to bump the shoulder back, are you bumping the shoulder further and further or are you increasing base to datum measurement?

 

[Tac-O]

If the case doesn't go far enough into the die, the base to datum measurement will likely increase. Then when you get it the die down far enough and the case goes far enough into the die, it will start to bump the shoulder back.

 

[Brad615]

If the case doesn't go far enough into the die, the base to datum measurement will likely increase. Then when you get it the die down far enough and the case goes far enough into the die, it will start to bump the shoulder back.

I'm confused here. When you're trying to bump the shoulder back, are you bumping the shoulder further and further or are you increasing base to datum measurement?

I'm confused myself Using hornady's headspace gauge kit I measured a fired piece of brass which measured 1.7385 using a mititoyo caliper. I then proceeded to size a cleaned piece of brass using reddings competiton shell holder starting with #4 which was giving me 1.7335. I then begin to use #'s 10,8,6,2 each time getting either no change or if it did change the measurement went further out. I then used a RCBS shell holder, and also adjusted the FL sizing die by slightly touching to cam over which I also did with all the redding shell holders as well. If the measurement did change it went further out & now the brass is at 1.7285. So no matter what I attempt I cant get the brass to move closer to the fired brass & 2 thou headspace of 1.7365. I'm obviously doing something wrong or my FL redding die is out of spec? As I stated above this brass has 4-5 reloads on them so the brass has been worked enough IMO? I'm racking my brain so I figured I would post on this forum as I respect the knowledge of the folks that post on here who know far more then I do. I've been reloading for 5 years now so I have alot of learning to go. Thanks for any help you can provide.

 

[Brad615]

I have never gotten a .002 shoulder bump with the die hitting the shell holder; rcbs dies, redding competion dies, and redding comp shell holders. I'm backed off about .010"

I'm going to try to back off the die as you stated & hope that solves my issue. Thank you.

 

[jimbires]

I'm confused myself Using hornady's headspace gauge kit I measured a fired piece of brass which measured 1.7385 using a mititoyo caliper. I then proceeded to size a cleaned piece of brass using reddings competiton shell holder starting with #4 which was giving me 1.7335. I then begin to use #'s 10,8,6,2 each time getting either no change or if it did change the measurement went further out. I then used a RCBS shell holder, and also adjusted the FL sizing die by slightly touching to cam over which I also did with all the redding shell holders as well. If the measurement did change it went further out & now the brass is at 1.7285. So no matter what I attempt I cant get the brass to move closer to the fired brass & 2 thou headspace of 1.7365. I'm obviously doing something wrong or my FL redding die is out of spec? As I stated above this brass has 4-5 reloads on them so the brass has been worked enough IMO? I'm racking my brain so I figured I would post on this forum as I respect the knowledge of the folks that post on here who know far more then I do. I've been reloading for 5 years now so I have alot of learning to go. Thanks for any help you can provide.

above you say you are STARTING by using the +.004 shellholder , this is causing you problems you're too short already . you must start with the +.010 shellholder . by using the +.004 first , you are making it to short . you can't make this brass longer by using a different shellholder . it will only get longer by loading and firing it .

using your specs from above ;

fired brass measures 1.7385
#4 shellholder gives 1.7335 this is .005 shoulder bump

it looks like you will need the #8 , or #6 shellholder . just start with the +010 shellholder and work your way shorter

 

[Brad615]

above you say you are STARTING by using the +.004 shellholder , this is causing you problems you're too short already . you must start with the +.010 shellholder . by using the +.004 first , you are making it to short . you can't make this brass longer by using a different shellholder . it will only get longer by loading and firing it .

using your specs from above ;

fired brass measures 1.7385
#4 shellholder gives 1.7335 this is .005 shoulder bump

it looks like you will need the #8 , or #6 shellholder . just start with the +010 shellholder and work your way shorter

Thank you.