A friend has a model 25 in 45 ACP and he's getting light strikes when using moon clips but works fine without them. I thought it would be the opposite but that's what he's saying. Most would fire after a second shot at it. Ammo was Remington UMC.

Anyone ever ran across a situation like this?

Moon clips may not be perfectly flat and acting as a spring washer to absorb firing pin inertia.

Yea, that. So is he using aftermarket moon clips? If so, my suggestion would be to try with the factory moon clips (only) and see if it's cured. That will tell you if it's the brand / batch of moon clips. If it still does it with factory clips (and factory ammo), the gun should go back. If the factory clips cure it, he needs to buy more factory /alternate brand clips.
hth

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Dave

Roger that, thank you guys. I was kind of leaning that direction myself but wasn't really sure how much play would be available with the rim and clip eating up some of the clearance.

One reason I do not care all that much for clips -- they can get slightly bent/warped, so slight you will not readily see it but enough that they will cause misfires. If you use them in a self-defense gun, my recommendation is to inspect them closely for flatness every time you load up a batch.

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Pisgah

Using a mooning/demooning tool will greatly decrease the likelihood of bent clips.
Worst danger is their being stepped on after being ejected onto the ground.

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-jwk-
US Army '72-'95

Using 45 Auto Rims further reduce the likelyhood of bent clips too... a lot.

.

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Waiting for the break of day

Yea, that says it all!

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Only difference Fool/Mule-ears

I've been reading threads and posts re; "light strikes" for some time on this and other forums. There is another cause that's been posted that I've found to have merit. That is the difference in thickness of the cartridge base of certain ammo manufacturers. I'm trying to get a photo comparing several brands. A slightly thinner cartridge base can cause a light strike. If anyone with good photographic skill happens to have, or can take such a photo, I believe it would add an interesting aspect to the discussion

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John

I too was getting at least 1 light strike with several factory brands of ammo when NOT using moon clips in my 25-2.

I got some full moon clips new on-line and they turned out to be a little on the thick side plus were a PITA to load by hand.

So I invested in the BMT Equipped moon tool (yea...$100 shipped) and also bought factory S & W full moon clips (S&W part number 191420000) which are also expensive small plastic blue & white plastic case with 4 moon clips resting on a piece of foam, $5.00. I bought all the S&W clips my LGS had (4 boxes) and since then...absolutely no problems with loading (no bending forces whatsoever with the BMT tool, either mooning or de-mooning) and the factory S & W moon clips all measure 0.040". The purchased on-line full moons measure 0.042" and have a very sharp edge on one side from the stamping process that will scratch the cylinder face or frame depending on how you load the clip. My cylinder would drag something fierce and DA was basically out of the question. I suspect now that these on-line buys are some sort of extra cheapo knock-offs.

In addition when I got my 25-2 included were six "supposedly factory S & W" half moon clips. These half moons do measure 0.040" and are like the full moon factories, nicely finished on both sides.

All in all I head for the range these days with 16 full moons already loaded of whatever ammo I have on hand (PMC Bronze, American Eagle, CCI Blazer Brass, etc.) and even mixed within any 1 moon clip and so far, zip, zero, nada FTF or even hard ejection issues. With the BMT tool, 1 quick twist de-moons spent brass into a 5 gallon pail, and 6 fresh rounds fully loaded in under 30 seconds.

I agree it is probably bent moons, but again...check for thickness too. With my 25-2 the clip thickness was the whole ball game.

Attached Images

M25 right side.jpg (37.8 KB, 12 views)

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Charlie B
SWCA#3083, SWHF#570

Since the revolver works correctly without moon clips and gets misfires with them, it seems clear that the moon clips are an important part of the problem. And you have received some excellent advice in this thread on how to resolve issues with the moon clips.

However, there is a possibility that the moon clips are not the only problem. It is possible that the firing pin strike is not as strong as it should be, and this could be aggravating the problem. Since the gun works properly without moon clips, you know that the firing pin strike is not too bad, but it may not have the extra margin of strength that is desirable in a gun where reliability is critical. The hammer strike may be quite strong, and the moon clips may be the sole cause of the issue, but it might be good to give the gun some overall checks.

The number one cause of light strikes and misfires is a lack of mainspring tension, but firing pin length, internal friction, headspace, endshake and other factors can also contribute. You can find information on this forum about how to check all of these areas.

The required strength of the firing pin strike also depends on your intended use for the firearm. On a competition gun, you might want just enough mainspring strength to get 100% reliability while also maintaining a light double action pull. But on a duty gun, you might a bit stronger hammer strike to insure an extra margin of reliability.

Based on the original problem, it does seem likely that the moon clips are the sole cause of the issue. But whenever I hear about light strikes, I recommend people to check the specifications in all the common areas which can lead to light strikes. Even though this case is a bit different, doing the basic checks might still be a good idea.