makin a snap cap

L

lightfootMT

Inactive
hi,
I have wondered about making my own snap caps for dry firing using a small drop of silcone rubber in the primer pocket, smoothing it off flush and letting it set up. does anyone know or have an opinion as to whether this would offer enough cushion for the firing pin? I have also heard of using a small plastic rod or eraser from a mechanical lead pencil whittled down and fit into the primer pocket.
thanks
LF
 
LF,

That might work. I would be inclined to use a harder/stiffer material, like one of the injection moldable urethanes. The same kind of stuff that a lot of hydraulic seals are made of. Recoil cushions are a good example of this stuff.

If you can get your hands on some of this, it usually melts at about 400 f. Chop it into small pieces, melt it in a spoon, or metal cup, over a flame, then use a spatula to mush it in the primer pocket. Once it cools, cure it at about 220 - 240 f for 8-12 hours. This will give it good resistance to compression set.

You could find this type of material on many childrens toys. Old inline skate wheels would be a good source also.

I've no idea how effective this would be, but it's the way that I would try first.
 
You really want something harder if you have a gun with a propensity for shattering firing pins. Delryn is commonly used. I would try drilling out and tapping the flashhole for a Nylon machine screw. Put the screw in with some of your silicone sealant and file it off flush with the case head. Put the case upright and mix and add enough epoxy to come up a half an inch or so to back up the screw.

Nick
 
I like that nylon screw idea. How about carrying it a bit further and slot the end that goes into the case so when the nylon gets a bit battered, it would be easy to just insert a screwdriver through the mouth of the case and screw out (or in) a little more nylon?

Years ago, I bought some nylon rods that are just a bit oversize for primer pockets. I trim a bit off, insert it, and cut it off. But the nylon screws sound even better.

Jim
 
try a couple of those ideas

I will give a couple of those ideas a try. I do own a fairly extensive tap & die set so the nylon screw idea might be doable. What about a real good epoxy like "J B Weld" stuffed in the primer pocket? I would think that would tend to "indent" after a few firings though. I ll see if i can come up with an inline skate wheel and melt that down. I will update with progress.
 
Using a relatively tough plastic to take the firing pin hit will extend the life of the unit. Making the slug fit the bore of the primer pocket for an easy slip-fit but a bit shorter than the depth of the pocket. That will permit you to glue it in using common silicone (RTV) sealer to give it some cushion.
 
I like Mike's cushion, too. Might save the whole thing from wearing out. I've seen snap caps with solid brass in the primer location. These may have a spring shock behind them, but a disk of inner tube or other neoprene as a backer might work, too. The silicone RTV could then be put on everything without concern. That on the sides of the solid slug will wear loose, but as long as what's on the pad holds out, you're OK. If it doesn't, you'll be looking around for a little brass slug.

Nick
 
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