Ahoy, Machinists

[Scrounger]

Photos below are of a deburring tool and deburring tool base, both made by RCBS, and likely used by everybody here. As we all know, the left side of the tool cuts an outside chamfer on the neck of the brass cases for us. It would seem to me that it could be modified (or a similar tool made) to cut a gas check groove on a plain base bullet. Not something we'd want to do hundreds of times a day, but still possible to put a gas check on a few dozen plain bases bullets for testing or whatever. What do you machinists think?

[357maximum]

Not a machinist, just thinking out loud...but it seems that a tool that is somewhat based on the old single blade box "hold and twist" type pencil sharpener could get the job done for that application.

[Boomer Mikey]

Just make a mandrel for your case neck turner that holds your bullet (pocket) and turn the base of the bullet to size.

Boomer

[Calamity Jake]

The problem is getting the cut shank perpendicular with the base, if it's not then the GC will not crimp square to the base. Now I know the boolet is softer than the check but it will still hold it off square to the base if the shank is cut wrong.

It wouldn't be that hard to set something up for the old style RCBS Case trimmer with a collet to hold the boolet and a cutter mounted on the other end simular to the Forester outside neck turning tool, that way you could control shank dia. and depth of cut.

Sounds like a project for Buckshot or PatMarlin when he gets setup.
I work in a machine shop and would try it myself if I had the time.

[Bret4207]

I thought of something like that Art. I came to the conclusion a collet and form tool type cutter would be the best bet. Shouldn't be too hard to cobble together.

[leftiye]

Just stick your plain base boolits in a collet in a lathe with the base sticking out, and turn down the base band to correct diameter for a check. (don't mash size the boolit in the collet).

[Cap'n Morgan]

All the suggestions above would do the job. Personally, I would go for a combination of Boomer's and bret's idea - case trimmer + and a form tool cutter. The form tool could easily be made from soft steel:

1 Drill a hole the size you want the shank to be.

2 Drill/turn a step to bullet size about .05" deep (gotta have something to guide the base while cutting)

3 Use a hacksaw and file to to put a three or four teeth profile on the bugger.

4 Use a Dremmel tool to sharpen the inner cutting diameter on top only, be careful to leave the guiding part intact.