Should Snap Caps Spark when dry firing?

[snorky18]

Searched but didn't find anything on this.

Just got an DAO airweight .38, and bought some of the Azoom aluminum snap caps to practice dry firing this 47 lb trigger before I went to the range.

I noticed when the firing pin falls, a small spark appears.

Is this "normal"?

 

[rcmodel]

Exactly were does a spark appear?

There ain't much to see inside a revolver cylinder with a snap-cap in it.

rc

 

[lesterg3]

No, quit rubbing your feet on the carpet.

 

[snorky18]

The spark is coming from under the firing pin as it strikes the primer.

 

[Just One Shot]

It must be your hammer hitting the frame because I've never seen aluminum create a spark!

 

[raz-0]

heck aluminum sparking, unless azoom changed something, the primer is some kind of silicone plug or other elastomer. I haven't seen those spark either.

 

[Hud]

Piezo-electric snap caps!

 

[KevinAbbeyTech]

Hmmm, that is a strange problem.
I would try using a different kind of caps if you can.
If those spark too, you know it's the gun.
Expensive though...

 

[makarovnik]

No. I use a-zoom snap caps. They are machined aluminum with a nylon primer.

 

[sherman123]

I have a 340pd and was told it can create sparks when the new gun is dry fired. Mine created sparks in the dark during dryfiring but that went away after several thousand dry fires.

 

[HammerBite]

Sparking firing pins is a fairly often reported phenomenon in S&W revolvers with hammer-mounted firing pins.

 

[CJ]

Phew. I realize it's an old thread, but was about to post a similar question...just noticed my new 442 sparking during dry-fire (even without snap caps).

 

[CoRoMo]

Sparking makes me think that a small bit of metal is being sheared off when two mechanisms contact each other with speed and force. I guess for those unfinished actions, that's a good thing; just completing what S&W didn't.

 

[Floppy_D]

Does it look like this?

 

[CJ]

I'm suspecting the possibility of static buildup too...I live in a very dry area, and it doesn't spark EVERY pull, just occasionally. I may need to experiment to see if grounding it does anything, or if which cylinder its indexed on makes a difference.

 

[BTin]

Has anyone ever documented erosion of the firing pin or other parts due to this electrical discharge?

 

[Jim K]

I have seen the same thing when snapping a 642 with the cylinder swung out. The spark is tiny, but it is there. I think it may be caused by compression of the air trapped in the firing pin channel. (If I recall correctly, Sam Colt actually made a revolver that ignited the powder charge by a jet of compressed air.)

Jim

 

[CJ]

Interesting. I figured it was a static release from the rubbing going on during the trigger pull, cylinder rotation, etc. combined with the really dry air around here lately.

 

[Floppy_D]

I doubt it's static, as it's all conductive metal and connected, so opposite charges couldn't build. That Colt revolver sounds pretty interesting.

 

[snorky18]

It happens with or without the snap caps. Every trigger pull. 99.9% sure it's not static, for a variety of reasons.

The compression of air thing sounds really interesting, I'll have to look into how that actually works.