How much should I take off?

[Dave T]

There has been discussions about shortening a full length sizing die by a few thousands to get it to size your cases to match your chamber, or to bump the shoulder back when the die doesn't seem to be working. My question is, how much should I take off? 3 or 4 thousands? 5 thousands and up? Is it trial and error? Anyone who has done this with a die, any advice would be greatly appreciated.
Dave T

 

[BoydAllen]

First of all make sure that the case "headspace" that you are bumping back from is from a case that has stopped growing in that dimension. It takes several warm loads. Secondly, how are you measuring bump? are yo knocking out the primer before measuring the fired case, before sizing? Third, shortening up the shell holder is much easier, and will get you to the same place. I would suggest starting with 5-6 thousandths and then see where you are. If needed, you can double that, just be accurate when you measure bump. If you bump .002 and the bolt is still not as free as you would like, you need a smaller die.

Added Later: It is easier to firmly reseat a fired primer well below the head, with your priming tool than to use a punch to remove them.

 

[bozo699]

First of all make sure that the case "headspace" that you are bumping back from is from a case that has stopped growing in that dimension. It takes several warm loads. Secondly, how are you measuring bump? are yo knocking out the primer before measuring the fired case, before sizing? Third, shortening up the shell holder is much easier, and will get you to the same place. I would suggest starting with 5-6 thousandths and then see where you are. If needed, you can double that, just be accurate when you measure bump. If you bump .002 and the bolt is still not as free as you would like, you need a smaller die.

Added Later: It is easier to firmly reseat a fired primer well below the head, with your priming tool than to use a punch to remove them.

I agree with this, I have always been able to take enough off the shell holder to achieve what was needed, most dies are hardened and it isn't a easy task removing material, some dies are built with a rounded lip for a lack of a better word on the bottom of the die that could be removed and would give you more clearance without effecting the sizing chamber but if it is a flat bottomed die you start removing chamber wall right away, most cases are tapered that can't be a good thing then to remove some of the die IMO.

I never use my sizing die to decap I use a decapping die or a hand punch and stand, but just for a quick check I guess reseating them would work fine,..that's why I keep you around Boyd your always thinking

P.S,.. Boyd I had to divert a disaster my son was creating sorry about the quick phone call I would like to finish discussing what we were talking about, I will take notes
Wayne.

 

[fdshuster]

.010" off the top of the shellholder has always worked for me.

 

[Eddie Harren]

"most dies are hardened and it is not an easy task removing material......."
And shellholders are not hardened? Every make of shellholder, that I have encountered, were just as hard as the dies.

 

[fdshuster]

A surface grinder does the job in a matter of minutes, and shellholders are a whole lot cheaper than sizing die bodies. Works for me, do whatever you like.

 

[NorCalMikie]

Only problem with a "surface grinder" is most folks don't
have one just sitting around waiting for a small grinding job.
Easiest way to shorten a shell holder is to chuck it up in a drill press and run it down on a well oiled sharpening stone. That takes material off in a jiffy and comes out with a smooth machined finish. 8) Most folks would be more likely to have a small drill press than a surface grinder in their home shop.
While you're at it, do a couple at different measurements, that way you're covered for future use. You may even get the same results with an electric drill but a press works best. ;D

 

[fdshuster]

NorCalMikie: Agree. I'm blessed with the friendship of a guy who has a hobby machine shop that includes a surface grinder, and also my local gunsmith/rifle builder could also do the same job with just a small cost to me.

Your idea of using a drill press would also be another option, one I will try the next time I need to alter a shellholder.

 

[TheSnake]

If you don't have a drill press, a sanding disk bit for your drill would also work on the shell holder.

 

[MGYSGT]

I ground the shell holder by handheld method, holding it against the side of the grinding wheel. Worked for me.

Tom

 

[itchyTF]

What about the Redding competition shellholders for those that don't have any of the above mentioned tools (other than a drill)?

 

[bozo699]

What about the Redding competition shellholders for those that don't have any of the above mentioned tools (other than a drill)?

Itchy,
The competition shell holders go the opposite direction,..ie there thicker not thinner.
Wayne.

 

[itchyTF]

Wayne,

Now I'm really confused (unless I'm having a senior moment). According to Redding - Each shellholder has a distinct black oxide finish and is clearly marked to indicate the amount it will decrease case-to-chamber headspace. You can now easily adjust the shoulder bump to customize cases to your specific chamber.
In order to bump the shoulder more doesn't that mean the case has to be driven into the die farther? To do that with the shellholder, doesn't it have to be thinner? ???

 

[BoydAllen]

I am not Wayne, but I stayed at a Holiday Inn once.

If you run your die down to touch a standard shell holder, and you end up with a head to shoulder measurement on the sized case that is less than you want, which results in more space between the case and the chamber, using a taller shell holder will leave the case longer in that dimension after sizing. In their explanation, Redding is using "headspace" to denote the clearance between the case and the chamber, at the shoulder, assuming that the case is touching the bolt face. They should have simply said clearance. When I use headspace to refer to the distance between a case's shoulder and head, I put it in quotation marks to indicate that I am talking some liberty with the proper use of the word, which is properly used to describe the the distance between a datum circle of specific diameter on the cone of the shoulder of the chamber to the bolt face of the action on which the barrel is installed.

 

[itchyTF]

I see my problem! The Redding shell holders are used with dies that bump too much with the standard shell holder bottomed out against the die.

I must have known that at some point because I've used them before.

 

[bozo699]

I see my problem! The Redding shell holders are used with dies that bump too much with the standard shell holder bottomed out against the die.

I must have known that at some point because I've used them before.

Aha,...it was a senior moment then wasn't it ;D no worries I have them all the time at 48, I hate to think what it will be like in another 20
Wayne.

 

[NorCalMikie]

Wayne: In another 20 years, you'll be that much smarter, that much older and probably won't be able to do the things you do now. Getting older isn't for sissies! But, you'll be getting senior doscounts. 8) Can't wait huh?

 

[bozo699]

Wayne: In another 20 years, you'll be that much smarter, that much older and probably won't be able to do the things you do now. Getting older isn't for sissies! But, you'll be getting senior doscounts. 8) Can't wait huh?

NO not at all : ,...................Smart alic
Wayne.

 

[holstil]

I don't think you can take off too much. You don't have to use all of the clearance you made. As long as you let enough meat on it to extract the case. ???

Jim