Gunsmithing Headspacing a resizing die

[GasLight]

Hello,

Just occured to me, that I need to know how to headspace the resizing die that I am making. My thoughts are that if I want .002" or more shoulder bump, I will need to leave it .002" or more short on the go-gauge? Should I use the chamber go-gauge and the shell holder, and then stop reaming when the shell holder is .002" to .003" (using feeler gauges) from the base of the die? Or should run the reamer in past the benchmark scribe on the reamer and then trim the die to that length.

Thanks for any help!

Dave

 

[Clark]

Re: Headspacing a resizing die

I have chambered with a go gauge and then adjusted the sizing die with the go gauge.

That is not as good as chambering with anything and adjusted the die until the cartridge gauge shows the shoulder or brass formed in the chamber to have been set back .001".

 

[300sniper]

Re: Headspacing a resizing die

i've never made one but i would think facing the die would be easier than reaming to an exact spot. i would think you would also want to make the die shorter than your target headspace to allow some spring back of the brass. again, i haven't done it but i could see that being an issue.

 

[GasLight]

Re: Headspacing a resizing die

yeah, hoping to get a figure, how short to make the chamber, I know you can adjust the die higher to compensate, but don't want the chamber too short or too long so you either can't full length size or shoulder bump.

Thanks

 

[Alan Warner]

Re: Headspacing a resizing die

Dave;
I send dies out the door .005 to .006 short. The system we make is also adjustable for HS via supplied shims. shoulder set back is entirely dependant on the state of hardness of the neck/shoulder area.
For the method you are building, I would suggest making it .005 short and employ the use of shell holders in .001 or .002 increments to give you some control. Preloading at the top of the stroke is important for consistant results.

A dead soft piece of brass will still spring back .001. Also, remember that your measured HS from your fired brass is some amount shorter that your actual chamber's HS.

A die with full length sizing will grow HS long as it is brought to the top of the stroke. Shoulder set back occures at the very top of the stroke.

HTH
alan

 

[DAVETOOLEY]

Re: Headspacing a resizing die

I leave .135" of the go gage sticking out. Has worked well for years. Gives you a little wiggle room. All presses have some spring in them. The larger the case the more pressure required and thus more spring. Most of the time having .010" to play with lets you set the die without putting a load on the press which makes it easier to adjust to where you just bump the shoulder.

 

[Clark]

Re: Headspacing a resizing die

Sorry, I miss read the question.

The Forster sizer dies are shorter than RCBS sizer dies.
The RCBS shell holders are shorter than Lee shell holders.

The most sizing can be done with a Forster sizer die and RCBS shell holder, that will push the case .010" smaller than the go gauge for chambering.

The least sizing can be done with RCBS sizer and Lee shell holder that will push the case .003" smaller than the go gauge for chambering.

 

[GasLight]

Re: Headspacing a resizing die

Alright, I measured my shell holder, and the depth of it is at .136", so I decided I would trim the die until I got .142" of the go-gauge extending from the bottom of the die. This should give me .006" to work with. I messed up a little, and will have a 60° chamfer on the end, but hoping this won't be an issue since it should be within the case head still. I need to thread the outside of it yet, and will update when I am done with that. Have a ways to go yet to see how well it turned out, but after I get it finished, I will be able to shoot the rifle at least