Handy tool for expanding gas check shoulders

[stocker]

I had several hundred 7mm gas checks attached to boolits that were plain defective due to a bad new mould. (RCBS replaced the mould under their warranty and yes, I should have checked better after the first few cast but this mould just worked too sweet to stop). After removing the lube and checks and annealing them I looked around the shop for something better to re-open the shoulders. I've used the ball bearings before and spent as much time chasing the bearing around the shop and sucking on bruised fingers as I did actually opening the checks.

In a little collection of leather working tools I had an assortment of punches for seating grommets and dome fasteners in leather and canvas. These are about 4" long which was long enough to get my fingers away from the hammer. The working head of these has a small dome with a taper to it's base. A quick check and one was found which was perfect for the 7mm checks. Worked slick as a whistle with a single tap and no cussing either. I have several of them in different sizes and suspect they are going to spend more time in the casting equipment box than the leather box.

[fourarmed]

A ball peen hammer of the right size would work nicely, I would think. Put the peen on the gas check and tap with a rawhide or wooden mallet.

[miestro_jerry]

What Fourarmed said is really good advice, I would use an arbor press or even my Rock Chucker press if I was doing more than a hand full.

Jerry

[NVcurmudgeon]

For .35 cal. I use a .22 Hornet case driven into a 7mm Magnum case, mouth to mouth. For .30 cal. saw the threads off a 5/16 bolt and grind a slight radius on the unthreaded part.

[Morgan Astorbilt]

Steel dowel pins, available from industrial suppliers like Enco and MSC, come in many lengths and diameters, and have radiused edges that are perfect for enlarging gas checks and case mouths.
Morgan