Case holder for use with prep center

[rhodesengr]

A 3 jaw drill chuck is going to distort the 357 cases

I understand, but not sure I see how it's worse than holding with your fingers. That is only 2-points. They will still go through the resizing anyway.

But I am going to order the ER collets because I like to experiment. I just wanted to see how the cheapy chuck worked first.

[ar15barrels]

I understand, but not sure I see how it's worse than holding with your fingers.

The chuck has a LOT more clamping force than your fingers.
Your fingers are also far more flexible than the brass so your fingers conform to the brass instead of the brass conforming to the steel chuck jaws.

[RandyD]

If you want to hold a case with your hands while case prepping, just wear a leather work glove.

[rhodesengr]

I did a bunch with the that cheapy chuck last week. Seemed to work fine and I didn't notice any deformation.

[divingin]

If you want to hold a case with your hands while case prepping, just wear a leather work glove.

I'd think dishwashing rubber gloves would give grip, a bit of protection, and be cheap enough.

That said, I'm not really sure OP needs to do all the prep work. But, it's his time and effort, so whatever.

As an aside, if the cases grab, try using less pressure and let the tools cut at the rate they want rather than forcing them. May or may not help.

[rhodesengr]

That said, I'm not really sure OP needs to do all the prep work. But, it's his time and effort, so whatever.

I started with primer pocket tools because I was having some trouble with Ginex primers being difficult to press in. I have a separate thread about that. But I am also enjoying learning about case cleaning and prepping for my hand-loads whether it is needed or not.

As an aside, what I have found is that no one seems to make a tool that "uniforms" the primer pocket diameter. All the "uniformers" are designed to only cut on the bottom and not the sides. The "reamers" seem to only cut a bevel at the top of the pocket. I understand that "reamers" are designed to remove a "military crimp" which is not an issue for me with my Starline brass. I have looked at all the primer pocket tools from all the main companies and have not found one that "uniforms" the diameter. Some of the Ginex primers press in OK and some were very difficult so that tells me either the primers are not uniform or the brass is not uniform. There is not much I can do about the primers but I thought i could at least make sure the pockets were not undersize. Apparently, no one makes a tool for that.

[ar15barrels]

I started with primer pocket tools because I was having some trouble with Ginex primers being difficult to press in. I have a separate thread about that. But I am also enjoying learning about case cleaning and prepping for my hand-loads whether it is needed or not.

As an aside, what I have found is that no one seems to make a tool that "uniforms" the primer pocket diameter. All the "uniformers" are designed to only cut on the bottom and not the sides. The "reamers" seem to only cut a bevel at the top of the pocket. I understand that "reamers" are designed to remove a "military crimp" which is not an issue for me with my Starline brass. I have looked at all the primer pocket tools from all the main companies and have not found one that "uniforms" the diameter. Some of the Ginex primers press in OK and some were very difficult so that tells me either the primers are not uniform or the brass is not uniform. There is not much I can do about the primers but I thought i could at least make sure the pockets were not undersize. Apparently, no one makes a tool for that.

Almost nobody makes a tool for that because it's not been a problem until Ginex primers hit the market.
The problem is the primers.

https://lewilson.com/primer-pocket-reamer

Call Wilson and ask them if their primer pocket reamer cuts the 0.175" diameter as well as the radius or if the cutting flutes are smaller than 0.175" on the 0.175" model so that the tool will only cut the radius.

[rhodesengr]

Almost nobody makes a tool for that because it's not been a problem until Ginex primers hit the market.
The problem is the primers.

https://lewilson.com/primer-pocket-reamer

Call Wilson and ask them if their primer pocket reamer cuts the 0.175" diameter as well as the radius or if the cutting flutes are smaller than 0.175" on the 0.175" model so that the tool will only cut the radius.

I have the reamers from RCBS and Lyman. They do have cutting flutes on the sides. They do not seem to help the Ginex primers. Probably the Ginex primers are just too big. I have tried to measure. I have tried to measure the reamer diameter but I just have cheap calipers and can not resolve the 1 or 2 tenths of a mil that would make the difference between a tight primer and and normal primer. But just going by feel, running either of those reamers doesn't seem to help.

[ar15barrels]

I have the reamers from RCBS and Lyman. They do have cutting flutes on the sides. They do not seem to help the Ginex primers. Probably the Ginex primers are just too big. I have tried to measure. I have tried to measure the reamer diameter but I just have cheap calipers and can not resolve the 1 or 2 tenths of a mil that would make the difference between a tight primer and and normal primer. But just going by feel, running either of those reamers doesn't seem to help.

There's not even a question that the primers are the problem.
I would not expect any primer pocket reamer to cut the pocket oversized as such a tool would ruin cases for use with standard sized primers.

Primer pockets are supposed to be 0.1745" diameter for small primers or 0.210" for large primers so don't expect to find any reloading tool made to enlarge that dimension.

What do your primers actually measure?
What do your tools that have cutting flutes on the sides actually measure?
Roll the tool through the calipers backwards to measure so as not to damage the cutting tool or the calipers.

According to these specs (which I did not confirm with SAAMI), there's 0.002" allowance for press-fit for small pistol primers so don't worry about 0.0001" measurements:

https://ballistictools.com/articles/primer-pocket-depth-and-diameter.php

[divingin]

I have an old hand tool for reaming the crimp from primer pockets (though I suspect it was for large primers, as I probably got it for 45ACP.) The cutting portion looks like an end mill cutting head, with no flutes on the end of the tool. It did not bevel the pocket at the case head. No idea what it measures.

[rhodesengr]

I ordered some stuff so I can measure the pockets and primers.
A half decent micrometer and a set of half-ball hole gauges.