Issue Bumping Shoulder

[jpistolero02]

I just had a 6.5X47 built. After firing a few rounds today, I was checking the shoulder measurement. For the life of me, I can't get the shoulder to bump back .002-.003. It appears my die is at it's max. I am using a Forster benchrest full length sizing die and Lee classic press. I am using a Hornday headspace gauge to check. Any ideas on what I am doing wrong?

 

[Bulseyetom]

Probably nothing. I have a 6x47 that I have the same problem except when I use my old Herters press and shellholder. It must be just a tad different in thickness someplace that allows me to get that extra .001. I remember asking this question and most told me to take a few thousands off of the shellholder. I am sure somebody who is a better machinist than me will chime in and tell you how to solve your problem but I believe your die is too long or your shellholder to thick to match your chamber. Tom

 

[jimbires]

first thought , if the die is touching the shellholder solidly , I'd try another shellholder .

second thought , are you getting a repeatable measurement with the hornady tool ? after you resize , are you moving the shoulder any , longer or shorter ? Jim

 

[BoydAllen]

Just out of curiosity, how many times have the cases that you are bumping been fired? The reason that I ask is that it has been my experience that cases do not reach their maximum shoulder to head measurement until they have been fired two or three times, with good (safe) hot loads. IMO bumping should be from the maximum rather than from a once fired measurement. In short, you may not really need to bump your shoulders back at all. How do the sized cases chamber?

 

[jpistolero02]

These are once fired cases. The bolt closes just fine. I have been trying to read up and get better with my loading so I was doing it for consistency sake. The measurements seem to be consistent between cases and don't change when I tighten the die all the way down. I can't go with a different shell holder because I am almost out of thread right now.

 

[Heavies]

Yep. I think if your cases chamber fine, with no resistance, then there is no need to bump the shoulder yet.

When the bolt starts to drag a little, then it is time to take your measurements and bump the shoulder the .002".

If you set up the die to bump at .002" when the brass is not at the maximum, then you will be sizing too much.

 

[NorCalMikie]

Like what already was said. If the fired case chambers without any excess resistance on bolt closing, you don't need to bump the shoulders, yet.

 

[Cigarcop]

I agree with all the above, your asking your die to do something it may not be capable of doing until the shoulder moves a bit more. Keep track of how far the shoulder moves on the first 3 to 4 firings and you'll get to a point where it won't move any further, then decide how far back you want or need to bump them.

 

[40X Guy]

I just went thru this with my 6.5X47L. I was using the Redding Body die along with a standard RCBS shellholder and Rockchucker press, no matter what i tried, I could not bump back the shoulders .002 on my twice fired brass, or they were getting bumped .004-.005 with overcamming the press and screwing die down 1/4 turn past contact with shellholder. Some were even getting longer headspace measurements if i had die past 1/4 turn. So I had .020 machined off a new RCBS shellholder, bought a new Harrell Precision .308 sized press, and also bought a new Redding FL S bushing die. Now I have a gap of about ~.005 between shellholder and die and am getting exactly .002 shoulder bump upon FL sizing. My rifle shot the best it ever did yesterday at a match. After FL sizing, I neck size with a separate operation. Some of these factory dies are made longer internally as already mentioned and this drove me crazy for a while but with help from this great forum it all worked out. Or you can order a set of custom dies based on your fired cases and there will be no issues like I just went thru.

Frank