Operating a rimless revolver without moonclips questions

[bikemutt]

Ignoring the obvious reason for using moonclips with a 45ACP revolver, allowing for easy ejection of spent casings, I wonder if shooting the gun without moonclips may introduce errors in accuracy and ignition?

I took some closeups of the open and closed cylinder both with and without a moonclip.

One thing obvious is the round goes further into the cylinder without the moonclip, can anyone speculate if that tiny difference could somehow affect accuracy?

The complement of that situation is, without a moonclip, the round is further from the firing pin with the cylinder closed, could that affect reliable ignition?

 

[5-SHOTS]

Without moonclips the head space decided by S&W is no more respected; I don't know if it could be a problem. Looking at the pics you are also going to have light strikes. And what about ejection? Without the moonclip you have to pray the spent cases to fall down and not always this happens.

 

[rcmodel]

On S&W's at least.

From 1917, until the introduction of the frame mounted firing pin guns?
It made no difference, because the chambers were head-spaced properly to work with or without clips.

Now, some of them are deep chambered, and are not 100% reliable without the clips.

Why the change after all those years, I have no idea.
But it was stupid, stupid, stupid!!

rc

 

[Sam1911]

Yeah...I'd say you're a bit lucky if they light reliably without the moonclips. Back in the day, like RC says, yes they were supposed to. But now that's not a design imperative.

 

[rcmodel]

I gotta guess it saves them .75 cents per gun to deep chamber them than it would to slow down and chamber them with the proper headspace like they did it for 65 years.

rc

 

[Driftwood Johnson]

Howdy

It is a matter of manufacturing tolerances.

It is impossible to design revolver that fires the ACP cartridge that will have exactly 0 distance to the chamber throats when when moon clips are also being used. Given the tolerance of case length, the position of the extractor grooves in the brass, the thickness of the rim, and the variation in thicknesses of the clips, you just cannot do it. Those variables will never be exactly the same from brand to brand of ammo and from clip to clip. There will always be a slight variation. If the case bottoms completely on the mouth at the step in the chamber, then there will be instances when the clip is hanging free by a tiny amount. There will also be instances when the clip snugs all the way down against the back of the cylinder but the mouth has not quite touched the step in the chamber. Instances of when the clip seats against the back of the chamber AND the case mouth touches the step in the chamber will be relatively rare.

Design engineers know all this, so they build in a little tiny bit of clearance. That is why you may notice the case seat slightly deeper with no clips on it.

For what it's worth, I never use moon clips with any of my Smith 1917s, and they always fire reliably. There is even tolerance built into how far the firing pin extends through the recoil shield for reliable ignition.

 

[Wil Terry]

THIS DEPENDS ENTIRELY upon how tight the headspacing is in the 45ACP sixgun in question.
I always have to use 1/3, 1/2. or full moon clips in my S&W M25-2 with rimless ammunition. Either that or the best of the lot 45AUTORIM.
I NEVER have to use any clips in the S&W M625-4 and it shoots like a million bucks one way or the other.
And so it goes...