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No shoulder bump

Mauser06

I had my Kimber Montana bored out and rechambered to 358win.


I had 308 Lapua brass and no 308....so I am probably one of the only guys with 358win Lapua brass...lol.

Redding FL die. I am getting zero shoulder bump no matter what.


Do I need "competition she'll holders" to get the shoulders bumped? Or is it just excessive headspace I have to live with? Any issues if it is excessive headspace? I'd guess brass might not last so long?...not a big issue as it's a hunting rig...I don't see cases getting fired more than a couple times each.

1x fired cases chamber just fine. Bolt closes nicely....which I don't think should be the case ..?

Haven't ran into this before. Thanx!
 
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Mauser06 said:
I had my Kimber Montana bored out and rechambered to 358win.

Redding FL die. I am getting zero shoulder bump no matter what.

Do I need "competition she'll holders" to get the shoulders bumped?
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Zero shoulder bump - with the die screwed down enough so the base is in contact with the shellholder to the point flex in the press is eliminated - assuming this, then no, the competition shell holders will not help you. They would only make it worse as they function in a similar way as backing out the die. The comp s/h set comes in increments of + 0.002. So if your setup gives you say 1.630 headspace, using a +0.002 comp s/h would make it 1.632, using a +0.004 gives 1.634 and so on.

You may have to skim the base of the die.
 
Martin has the comp shell holder explanation down . If a standard die and shell holder screwed down to make firm contact or cam over does not bump your shoulder back enough. That’s an indication of short headspace in the chamber not excessive . Although not unheard of it’s relatively rare but a standard die cannot size a case down enough to fit in your chamber . My Redding 308 dies size my case from head to datum about .004 smaller then a GO gauge . Meaning if I can’t size my case down enough using those dies , the chamber is out of SAAMI spec .

Two ways to size a case more than a standard die and shell holder will allow . Grind material off the shell holder to allow the dye to size the case more or Shim the case up while it’s in the shell holder by using feeler gauges under the head .

Oh feeler gauges that reminds me of somebody that I have not seen around for a while . Although I was not a fan I hope he’s doing well
 
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It usually takes more than one firing for a case to get tight shoulder to head in the chamber. Given that until it does, it does not need to have its shoulder bumped back (which only needs to be done if clearance is needed so that a case will not be tight), you are probably getting ahead of yourself. If you want to do an experiment, deprime a fired but unsized case with a punch. put a piece of Scotch tape on the head. The thickness of the tape is about .002. Trim the tape with a sharp pointed blade (Exacto works) so that the primer pocket is open and the outside is trimmed to the chamfer at the edge. With a film of bolt grease on the back of your bolt's lugs to prevent galling, try to chamber the case, but do not force it. If it is tight, then you can work with your die setting to the point where it feels right on closing, but just barely. Assuming that you can set the die so that you get the bolt closure you want, you can leave the die at that setting and if any cases get longer than that at the shoulder, sizing them at that setting will bump the shoulder the needed amount. As your brass becomes more work hardened from repeated firings and sizings you will eventually have to make a very slight adjustment of the die to give the same sized shoulder to head dimension. On more thing, measure your fired but unfired case for shoulder diameter and diameter a little in front of the extractor groove. Write these measurements down and do the same measurements after sizing. They should be slightly smaller than the fired case. The reason that this is important is that you need to know that the die is small enough inside to reduce the diameter of the body of the case, so that the difference in feel as you adjust the die is only caused by the fit at the shoulder. The competition shell holders start at standard height and get taller by .002 increments, so they will not solve your problem. If you cannot bump a tight case you will need to go the other direction, shortening a shell holder by a few thousandths.
 
That’s a good point Boyd , I wasn’t considering the OP was trying to fire formers cases at the same time . They very well may not have blown out enough yet
 
BoydAllen said:
Given that until it does, it does not need to have its shoulder bumped back (which only needs to be done if clearance is needed so that a case will not be tight), you are probably getting ahead of yourself.
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Yes.
Never could fathom why 'bumping' would become a mandatory step if indeed the bolt closed normally. On my oldest BR rifle (1975) in 222 Remington some of the brass has at least 35 reloads on it and consistently (the wind and ME have to do our part) fired in the 2's and some times in the 1's. It's as good as I can shoot. There was no bumping involved nor any need to that I could see. This is about as good as I'll ever do. Granted it's a cartridge that is 'easy' on the brass. But my point is bumping would be done for a reason and not necessarily as a required step. Maybe I'm missing something here but with me shooting that rifle and my reloads it's not getting any better for me, and that's with 45 years of practice with that rifle.
 
I like the competition shellholders , you can size with full contact without oversizing like the standard shellholder. My rounds would shorten do to expansion so I had to go another route in finding my chamber length using the Go Gauge.
 
I have a Rem Model 7, 223 Rem with a Douglas Match barrel which exhibits the same issue. A full length resized case (die adjusted to make shoulder contact so as not to extrude i.e. lengthen the case) measurement is the same as a fired case with primer removed. Thus I'm at zero head space after sizing. Trying to bump the shoulder any further by adjusting the die for more cam over places too much stress on the press.

The bolt closes perfectly with these cases sized as described, only a slight resistance so there is no need to bump the shoulder any further. As Boyd suggests, I monitor case headspace (fired) to determine if further sizing is needed as the cases age due to repeated firing and sizing. Thus far, after 7 reloadings with this current lot of cases, no change has been required.

Bottom line: I believe as the long as the case chambers without force and is not over sized such that it creates excessive head space you are at optimum sizing.

PS: It may be helpful to read the article by Todd Spotti entitled "Dealing with Headspace" on the Redding-Reloading web site.
 
K22
Most of the problem with my cases shortening was do to me loading mild loads , they would expand slightly and when sizing with the lowest deck height on the Redding Competition shellholders I could get a constant .002 case headspace measurement . You can do the same thing with the standard shellholder and backing out the Full Length die but I like full contact when sizing.. l like using the stripped bolt method in finding datum and ogive settings . Closed bolt for datum and raised for ogive.
 
Thanx all!


Lots of good info as usual!


I wouldn't say I am a new handloader....but self taught and limited experience. I know enough to load safe ammo. This year I've been trying to get more info the precision, data keeping etc.


After looking at some other suggestions, I will keep an eye on the brass and see what happens to it before I do anything else.


Didn't know what the proper course of action is....aside from load it back up and shoot it.
 
If it chambers after you sized it with no bump yeah I’d go ahead and shoot it . I’d also consider maybe just neck sizing it and shooting it that way. This should blow your shoulders out the rest of the way and form your case completely to the chamber . I should add as CW did , if you’re shooting mild loads you may never blow your case out to full chamber dimensions .

Off topic but Im going to rant here . What’s up with needing to click on watch thread if you’ve already posted in it ???? Why would I post in a thread I have no interest on seeing what other people have to say . It would be like walking up to a group of people in a deep conversation . Interrupt them give them my point of view then walking away never caring what anybody thought of me or what I had to say . If a member posts in a thread I think he obviously is interested in watching it , it should be an automatic to get the alerts !!! Many times I’ve gotten an alert telling me somebody quoted my post only to find that there were 30 other posts after mine I never knew were there .

End rant
 
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Metal God said:
Off topic but Im going to rant here . What’s up with needing to click on watch thread if you’ve already posted in it ???? Why would I post in a thread I have no interest on seeing what other people have to say . It would be like walking up to a group of people in a deep conversation . Interrupt them give them my point of view then walking away never caring what anybody thought of me or what I had to say . If a member posts in a thread I think he obviously is interested in watching it , it should be an automatic to get the alerts !!! Many times I’ve gotten an alert telling me somebody quoted my post only to find that there were 30 other posts after mine I never knew were there .

End rant
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This is a great forum, with a wealth of information from the members, but I gotta say the software is pretty bad. I almost never get notifications even when I manually watch a thread. I hope the upgrade fixes it.
 
Kratos said:
This is a great forum, with a wealth of information from the members, but I gotta say the software is pretty bad. I almost never get notifications even when I manually watch a thread. I hope the upgrade fixes it.
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Huh. I never fail to get a notification. Check your spam folder?
-
 
Kratos said:
This is a great forum, with a wealth of information from the members, but I gotta say the software is pretty bad. I almost never get notifications even when I manually watch a thread. I hope the upgrade fixes it.
Click to expand...
Works 100 percent for me, maybe something on your end?
 
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