I'm probably crazy for doing this, but I hate buying things I know I can make myself. Plus, I'm one of those guys that gets something in their head, and I have to make it a reality. So here I am, making my own damn snap caps.
I used to make brass chassis slot cars, so I had the brass around already. I use K&S brand, because it's good and it's available at my local mom and pop hardware. With all that being said, here we go.
I started by drilling out the primer pocket, and sleeving it with a piece of 7/32 brass tubing. This is the pocket that the plunger will ride in. It is soldered into the case.
Next, I constructed the plunger. It's a piece of 3/16 brass rod, with a section of the 7/32 tubing slid over it. This will act as the stop to keep the rod flush with the case head, like a primer. It will also give the spring something to bear against.
The next step was to drill a hole part way through a bullet, to accommodate another piece of 7/32 tube for the spring to attach to. Once the spring is attached, it is slid over the post of the plunger. The assembly is now ready to go in the case.
My calculations worked out pretty good, the plunger sits just about right.
I put the case in my press and flared the mouth. Then once the assembly was done, I seated the bullet with the press also. I then ran it through the factory crimp die, to make sure the bullet stayed where it was supposed to. It will be getting cycled through my 66 rifle, so I don't want it coming apart.
Once the snap cap was complete, I drilled two 1/8" holes in the sides of the case. I did that for two reasons. 1.) so I know at a glance if I've grabbed a loaded round or the snap cap. 2.) So I can put a drop of oil in it once in a while to keep it lubed up and working.
I ran it through my Winchester about 20 times, without a hitch. Now I just need to make 9 more.
Like I said, I must be crazy to go to these lengths for something I could buy. But it gives me satisfaction to make things myself. Besides, mine will probably far outlast the crappy plastic ones that are for sale.