Snap-caps, anyone?

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boomer1911a1

boomer1911a1

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I trust that everyone reading this already knows, but for any newbies, I'll restate it again: It's okay to dry-fire most cernter-fire firearms, but doing so to a rimfire will damage it.
Knowing that, I typically put an empty shell in the chamber of my Ruger .22 autos so I can drop their hammers (by pulling the trigger) and store them without the mainspring being under tension.
Well, I decided to move up to a snap-cap (not sure of the brand.) It appears to be solid aluminum, anodized a royal blue. Well, I bought two at a price of about $3 each, loaded them up, and proceeded with some dry-fire practice.

I couldn't believe how much a half-dozen hammer strikes chewed that thing up! The impact marks looked just like they do on a brass shell casing. I guess that's logical, as brass and aluminum are pretty close on the Rockwell scale, but I expected more durability from something intended for this exact use.

Right? That's what they were made for, right? Or are they inteded for some other purpose? Should I have gone with plastic?
 
Make sure they are actually intended for dry fire and are not just dummy cartridges.

I made the same mistake a while back with some .22lr dummy rounds. After getting annoyed at how beat up they got I dug out the package and sure enough, right there in dayglo letters it said "NOT FOR DRY FIRING"

Well I felt silly. I took quite a bit of shopping around to find .22lr that was actually intended for dry fire.
 
Count:
Allow me some exaggeration for the sake of illustration, here.
The firing pin on a rimfire is not a "pin" or "nail" with a rounded tip, like, say, a 1911 firing pin. Its tip has a rectangular "footprint" and has sharp corners to better bite into the brass of the .22's rim. I think of it as a miniature flat-bladed screwdriver tip.

Dry fire a centerfire pistol -- Glock, let's say -- and the firing pin pops out of its hole and hits nothing but air. No harm, no foul. (I think I've heard you shouldn't dry-fire an older S&W revolver with the firing pin on the hammer, but I can't swear to it.)

If you do the same to a rimfire, that screwdriver tip shoots out and smacks straight into the chamber face. Do this repeatedly, and it will mushroom the tip of the firing pin AND deform the breechface, which can in turn lead to chambering/extraction problems.

I confess that I heard all this as a child and took it as Gospel. I've never done any terminal experiments with any firearm, so this may be apocryphal. And sure, every once in a while, I'll slip and dry-fire my Rugers, yet have noticed no ill effects. Once a year probably is too little to hurt...
 
The Ruger Mk IIs and IIIs are safe to dry fire. The firing pin stop (A/KA 03500) prevent the firing pin form hitting the edge of the chamber.

From the section "TO ULOAD" in the Mk II's manual:

5. With the muzzle pointed in a safe direction, push the safety to the “off” (F)
position and pull the trigger to decock the pistol. The pistol can be dry fired as
long as the firing pin stop is in place (See NOTE in step 5 on page 21).



The aluminum rimfire dummy rounds (from manufacturers like Azoom) are meant for function testing of the firearms ONLY. They are not meant to be used as snap caps as you've seen as they will get deformed very quickly.
 
Clickclick + HKSW:

Oh, expletive deleted! I don't have the package as I bought them from my gun store individually, but they are clearly marked .22LR DUMMY ROUND. Sounds like I did exactly what you described.
What did you get to replace them?
 
Snap caps is a brand name, their brown in color and have clear rubber like stuff where the primmer would be ,they work great but a little spendy

They do wonders for your trigger control..
 
I made my own "snap caps". I'm sure they aren't as good as the store bought ones but they make me feel better. I loaded up dummy rounds with empty primer pockets and put silicon in the pockets. There has to be some cushioning effect, but probably these aren't as desirable as genuine snap caps.

On my 1911s, I've started putting "O" rings in the slot in the rear of the slide with the firing pin located in the center of the ring which seems to cushion well.

I know they say it's OK to dry fire but I feel better when I do one of the above options.

foot note: I think I read that on the Ruger 345 that you must have the magazine in place when dry firing to avoid problems.

Cloudpeak
 
There is an Italian company that makes rimfire snap caps (the term 'snap cap' now being a general term from the original Snap Cap product much like bandaid) made entirely of plastic (colored red). Eventually, they will also wear out (a little faster than centerfire snap caps) like the aluminum dummy rounds but are much cheaper. Or, you can do what a lot of folks do (including myself) and use spent casings in rimfire guns that require a snap cap to protect the chamber. Remember, the Mk IIs and IIIs are dry fire safe and don't need them.

Also, other makers like Pachmayr and Triple K (probably the only good product to come out of that company).
http://www.lymanproducts.com/pachmayr/snapcaps.htm
http://www.cowboyneeds.com/A799.html
 
It's not always true that you can dry-fire center fire handguns and not do any damage. True, the firing pin won't hit anything in front of it, but an internal shoulder might get battered and cause the tip of the firing pin to break off. It's also hard on firing pin springs that can get mashed if nothing in the chamber stops the pin's forward travel. The 1911 pistol is an example of this, and those that do a lot of dry-firing should replace the spring on a regular basis - unless there is a snap-cap in the chamber.

A hint to those with pistols. If you have to hand-cycle the slide to cock the hammer, file a little notch in the snap-cap's rim so that the extractor won't keep pulling it out of the chamber. Use a cleaning rod to extract and eject the snap-cap when you're done. :evil:
 
Last edited:
Old Fuff said:
If have to hand-cycle the slide to cock the hammer, file a little notch in the snap-cap's rim so that the extractor won't keep pulling it out of the chamber.
Click to expand...
Could be useful for tap-rack-bang drills without flinging snap caps all over the room. Thanks.
 
Ive put snap caps in every firearm that holds bullet. Metal stress is metal stress. Been doing it for 40 years, am not going to stop any time soon
 
Ive put snap caps in every firearm that holds bullet. Metal stress is metal stress. Been doing it for 40 years, am not going to stop any time soon
Click to expand...

Modern designs have addressed this issue and with steel, there is a thing called fatigue life when designing them. When the forces involved are below the fatigue life, you get infinite life out of the item. Now, accessing the engineering documentation that provides you with the fatigue life of said firing pin, that's another matter and I've never been able to find that information, anywhere. But trust me, it is buried somewhere in original design documentation, but very likely something we shall never be able to see or find unless we are in the business of manufacturing firearms.

I really wish I could find this type of info as a mechanical engineering gearhead type. Yes, I'm a nerd. No glasses or tape on said glasses though.
 
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