Did you ever try this?
I took a 5" piece of pipe the with threads on each end and welded a handle coming out the side of it. Then I cleaned one end up enough to slide a cartridge in, screwed the pipe caps on the end and I had an inertia bullet puller. It worked.

I made one even more simple. I threaded some gas pipe and fittings together to make a bullet puller for 12.7x108.

Yes, Gas pipe! That is what I used too. I just didn't explain it very well.

I just made one out of plywood with a hole bored in it. Held the case in the top with duct tape. Seriously Bubba, but it works

That is cool!!