Homemade .30-40 Krag Snap Cap

[OrlonTheBrave]

Hello friends,

Thought I should post here a project I finished a month or two ago.

I wanted to get some dryfire practice in on my Krag, but didn't want to subject the 120-year-old firing pin to undue stresses. While a few places online sold Krag snap caps, they mostly had a few issues: 1) they're designed as dummy rounds, with nothing in the primer pocket, 2) they have some sort of rubber in the primer pocket, which might not withstand repeated dryfirings, and 3) they're rather expensive. So, I thought I would see if I could make a spring-loaded .30-40 Krag snap cap using scrap and some hardware store screws. Here's what I came up with:
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The first step was drilling out the primer pocket to make sure the primer/screw could move back and forth freely. For this, I used a case with a loose primer pocket, a hand drill, and a vise.
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Next I flattened a used primer, JB welded it to the screw head, drilled a hole in a .22 case, and cut both cases to length. I didn't take any pictures of the process, but here's the final product--I wrapped everything in masking tape to keep it together.
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Finally I fed the whole contraption in through the case mouth, used a nylon toilet bolt as a spacer, and seated a bullet on top with a tight crimp. In my first attempt I seated the bullet too far and crushed the .22 cases, and had to remake them. Anyways, here's the final product.
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It's held up to a few hundred dry firings and seems just fine.

[15meter]

Glad it worked for you, I make much simpler snap caps, I take a fired case, drill and tap for either 5/16-18 or 8-1.0 in metric. Trim off enough of the shoulder so I can thread a nylon screw in from the front. Thread it until it is flush with the head of the case and your done.

The nylon screw will take a considerable number of strikes before you have to thread it out and file it flat again. Then thread it back flush with the case.

Made a number over the years like this, tough to find or stupid expensive to get snap caps in things like 8x50R, 280 Ross or 7x61 Sharpe and Hart.

The inch ones were using screws I bought at the hardware store, the metric version was donated screws from a Ford plant.

Haven't managed to wear one out yet.

I've done the same with shotgun shells, the old Winchester compression formed hulls seemed to work the best.

[country gent]

Good Job.
I have been going to try the nylon tipped set screws and just tap them into cases. 5/16 24 may work for most cases.

[OrlonTheBrave]

Thank you both! Ya know, I really like the idea of using some sorta nylon screw instead: I like the idea of threading it out further as needed, plus it sounds a whole lot easier than what I did. If you're threading the bottom, do you still need to drill out the primer pocket? I imagine there might be a gap otherwise.

[country gent]

There will be a gap but as long as the firing pin is hitting the plunger the gap is just there it dosnt matter. Drill and tap the case for a 5/16 nylon point set screw or a plunger type thread it in and go. the gap wont matter around the plunger. But the thin case head might make getting enough threads to get the nylon tip or plunger back to just below tricky. Here filling the case with epoxy before drilling and tapping will give the need thread depth. Also a fine thread set screw will give better adjustments.