Does anyone know of a source for custom moon clips? I need some half-moons in 45 Colt for a converted S&W M1917. It still shoots 45 ACP just fine, but I get lots of failures-to-fire with the 45 Colts. The cases often go down too far into the chambers, resulting in too light a primer strike. I know there are other ways to approach the problem, but I'd really like to try this first.
45 Colt Half-Moon Clips
- Thread starter erikpolcrack
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DWalt
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I don't remember ever seeing any such clips and I do not know how they could be made for a .45 Colt case. Seems as though whoever did the rechambering of your cylinder didn't know how to do it. I would just use .45 ACP and moon clips only in it under the circumstances and forget using .45 Colt.. Or maybe use .45 AR.
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If they’re made you’ll find them if you do a google search.
If not just use a Dremel tool to grind acp clips a bit larger to fit 45 Colt cases.
There’s another old trick that’s easier: use full moon clips. Grind the half circles large enough for Colt cases to slip thru easily. Lay the clip on the cylinder and just load the cartridges like normal.
If not just use a Dremel tool to grind acp clips a bit larger to fit 45 Colt cases.
There’s another old trick that’s easier: use full moon clips. Grind the half circles large enough for Colt cases to slip thru easily. Lay the clip on the cylinder and just load the cartridges like normal.
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BLACKHAWKNJ
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Recall reading that the 45 Auto Rim had a thicker rim than the 45 Long Colt.
Yes, it does. It was introduced after WW I for folks who didn't want to use .45 ACP rounds with clips.
TK Custom makes moon clips for .45 Colt on cylinders they have machined to shoot it. You should check with them to see if they will work on your cylinder.
Guy, that’s right I remember them now. Eric’s cylinder won’t need machining, the Colt cases already go too deep. It just needs the moon clips as a spacer. Regular moon clips for acp are too thick.
OP
Thanks, guys! I appreciate all your inputs. First thing I will try is the 45 Colt moon clips I just ordered from TK Custom. Hope they work as is, or will without too much fitting.
TK clips will work, they’re marked .025” thick. Acp clips are .040”. When I did what you need to do for 45 Colt years ago before TK was making clips I had to thin the clips on a surface grinder.
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Murdock
Member
Regarding converting a 1917 to .45 Colt, George C. Nonte's book (long out of print) Pistolsmithing has a section in it on how to epoxy a metal disk of appropriate thickness to the cylinder extractor star, then carefully open chamber holes in the disk to accomodate the .45 Colt cases.
Were I to do this today I would start with a full moon clip as suggested above, and try to attach that to the extractor star with epoxy. This would still require some careful hand work. Full moon clips are cheap if you screw one up attempting this.
Were I to do this today I would start with a full moon clip as suggested above, and try to attach that to the extractor star with epoxy. This would still require some careful hand work. Full moon clips are cheap if you screw one up attempting this.
That will work well. It just negates shooting 45 ACP OR auto rim anymore.
Actually instead of grinding/enlarging the 3/4 circles in the clips so 45 Colt will slip thru, you could just snip off the T shape piece between the circles and the clips will work just as well.
clips on the 45 colt cases WILL NOTWORK in his gun. His gun works with 24 acp and clips, A 45 acp rim is .049 and a normal clip is .040 for a total of .089 and 45 auto rims rims are .087. A 45 colt rim is .060 so a opened up acp clip would give a total of .10 and I doubt the cylinder would close or cycle.
A 45 colt cylinder cut for moon clips would need an additional .040 cut from the center of a 45 colt cylinder WHICH IS ALREADY .012 shorter to the rear than an ACP cylinder.
Besides that a clip for a 45 colt would be very delicate and flimsy. Take a look at an ACP clip the think about removing .022 from the inside radius of each slot so it would be big enough for a colt case. That would mean the arms in the area between the center of 2 cases would be .022 narrower
The Fixes for his gun to fire 45 acps and 45 colt are. Get a short 45 colt cylinder from a 25-3 or have one made from a N frame 357 cylinder. You could then have that cylinder cut for 45 acp in full moon clips or just swap cylinders from the present one to the correctly made colt cylinder. The other fix if fit a 45 colt extractor and then fire the acps in 1/2 moons after thinning the ends of the colt star arms
One could also silver solder a .035-.040 ring around the rear of the present cylinder for the colt brass rims to head space on.
Be aware that a real colt cylinder being longer towards the rear will need the frame lug filed back in order to fit a gun set up to fire ACP.
I have been making 45 colts from acp gun, from 357s and 44 mags, making dual caliber 45 cylinders and setting up guns with a cylinder for each for quite a while.
Starting with a 45 acp cylinder and making it able to fire 45 colts is NOT the way to go.
You could get some clips water jet or laser cut from .030 spring steel.
A 45 colt cylinder cut for moon clips would need an additional .040 cut from the center of a 45 colt cylinder WHICH IS ALREADY .012 shorter to the rear than an ACP cylinder.
Besides that a clip for a 45 colt would be very delicate and flimsy. Take a look at an ACP clip the think about removing .022 from the inside radius of each slot so it would be big enough for a colt case. That would mean the arms in the area between the center of 2 cases would be .022 narrower
The Fixes for his gun to fire 45 acps and 45 colt are. Get a short 45 colt cylinder from a 25-3 or have one made from a N frame 357 cylinder. You could then have that cylinder cut for 45 acp in full moon clips or just swap cylinders from the present one to the correctly made colt cylinder. The other fix if fit a 45 colt extractor and then fire the acps in 1/2 moons after thinning the ends of the colt star arms
One could also silver solder a .035-.040 ring around the rear of the present cylinder for the colt brass rims to head space on.
Be aware that a real colt cylinder being longer towards the rear will need the frame lug filed back in order to fit a gun set up to fire ACP.
I have been making 45 colts from acp gun, from 357s and 44 mags, making dual caliber 45 cylinders and setting up guns with a cylinder for each for quite a while.
Starting with a 45 acp cylinder and making it able to fire 45 colts is NOT the way to go.
You could get some clips water jet or laser cut from .030 spring steel.
OP
Which S&W Model 45 Colt extractor will work with my M1917 cylinder? Will it work with the M1917 ejector rod?
StrawHat
SWCA Member
Steelsaver has a very good explanation of the differences of chambering 45 Colt in a 45 ACP revolver and I had to take some measurements.
The cylinder gap between the rear and the recoil shield is .120". Measurements of the clip and base of the 45 ACP round measure .090" with my clips. My 45 Colt rounds measure .060" rim and a narrow slot just above measures .040". It would seem that the perfect clip would be .030" thick?? Is this wrong thinking? Do they make a clip with that thickness for 45 Colt?
The cylinder gap between the rear and the recoil shield is .120". Measurements of the clip and base of the 45 ACP round measure .090" with my clips. My 45 Colt rounds measure .060" rim and a narrow slot just above measures .040". It would seem that the perfect clip would be .030" thick?? Is this wrong thinking? Do they make a clip with that thickness for 45 Colt?
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OP
Steelsaver has a very good explanation of the differences of chambering 45 Colt in a 45 ACP revolver and I had to take some measurements.
The cylinder gap between the rear and the recoil shield is .120". Measurements of the clip and base of the 45 ACP round measure .090" with my clips. My 45 Colt rounds measure .060" rim and a narrow slot just above measures .040". It would seem that the perfect clip would be .030" thick?? Is this wrong thinking? Do they make a clip with that thickness for 45 Colt?
TK Custom now offers six round 45 Colt moon clips .025 thickness and says they will fit all S&W revolvers with rear of cylinder machined to accept moon clips.
Look here is how I modified a 35acp to fire properly headspaced 45 colts with no clips, 45 acps in 1/2 moon clips for 1 of my 325 snubs
I fitted a 45 colt extractor to the ACP cylinder that I reamed deep enough for 45 colt cases, then milled just the ends of the arms down to match the cylinders original surface. This leaves the center section of extractor at correct height for rimmed cases
When 45 colt cases are installed in chambers the center of extractor holds them high off rest of cylinder
45acps in 1/2 moon and 2 45 colt and empty chamber
6 45 colts
6 45acps in 2 1/2 moon clips
I fitted a 45 colt extractor to the ACP cylinder that I reamed deep enough for 45 colt cases, then milled just the ends of the arms down to match the cylinders original surface. This leaves the center section of extractor at correct height for rimmed cases
When 45 colt cases are installed in chambers the center of extractor holds them high off rest of cylinder
45acps in 1/2 moon and 2 45 colt and empty chamber
6 45 colts
6 45acps in 2 1/2 moon clips
That’s true but TK is talking about fitting all S&W revolvers chambered in 45 Colt. Your 1917 originally chambered for ACP is already short enough to use clips with 45 Colt. In fact it must have the clip thickness for the firing pin to reach the primer with sufficient force to fire reliably as you discovered.
The chambers in your cylinder were reamed too deep. Many 1917s have successfully been converted to 45 Colt by only reaming .020” to .030” shorter so the Colt rims are .020” to .030” from touching the rear face of the cylinder. That’s why your cylinder will work just by using the TK CLIPS. But you have to snap the cartridges into the clips to use them as they are. By modifying the clips as I suggested above, you avoid that inconvenience.
By modifying the clips and gluing them to the extractor (or leaving them loose) you will achieve exactly what steelslaver shows above and still be able to shoot 45 acp, but only by using 1/2 moon clips, not full moon clips.
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If you know what your doing, you Could fit a rimmed cartridge extractor to the ops cylinder and then modify it by thinning the ends of the arms similar to above and 45 colts would headspace and fire correctly and 45ACPs could be chambered and fired in moon clips.
A better solution for the OP would be a short 357 or 44 special reamed to 45 colt or a 25-3 45 colt cylinder, recessed in the center for 45 acp in full moon clips. So, I went though my large caliber cylinder stash and found one of the original ones I had made from a 357 cylinder and recessed. It even has a extractor that used right hand thread ejector rod, so he can use his large knob rod, center pin, collar and springs etc. I fired a bunch of both though it before I made a long 45 colt cylinder for the model of 1955 I had it in so I could have another 5 screw, pinned and recessed 45 colt.
It was just collecting dust on a shelf so I am going to put it in the mail tomorrow.
A better solution for the OP would be a short 357 or 44 special reamed to 45 colt or a 25-3 45 colt cylinder, recessed in the center for 45 acp in full moon clips. So, I went though my large caliber cylinder stash and found one of the original ones I had made from a 357 cylinder and recessed. It even has a extractor that used right hand thread ejector rod, so he can use his large knob rod, center pin, collar and springs etc. I fired a bunch of both though it before I made a long 45 colt cylinder for the model of 1955 I had it in so I could have another 5 screw, pinned and recessed 45 colt.
It was just collecting dust on a shelf so I am going to put it in the mail tomorrow.
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