Anyone else done a 45ACP moonclip conversion on their 45LC?

aterry33

aterry33

Member
Joined
Mar 22, 2009
Messages
1,037
Reaction score
28
Location
Charlotte, NC
I had my 625-6 45LC Mountain Gun cylinder cut to accept 45ACP moonclips earlier this year. I only got to shoot a few boxes of ammo through it at the time but I was happy I did it.

I just got to take it out and shoot a lot more through it. I've heard people have had problems with accuracy shooting the 45ACP through 45LC cylinders (something about the 45ACP having more bullet jump through the longer LC cylinder) but I haven't noticed any appreciable decrease in accuracy.

I always wanted a 45ACP revolver and I was considering buying a 45ACP Mountain Gun, but overall, I'm happier that I can now shoot either. I wasn't going to cut the cylinder in my 25-5 in any case.

Anyone else tried this modification?
 
Register to hide this ad
always wanted to, never found the shop/OR the $$ to do such.

Got photos?
Where & how much, I may join your club!
 
<I always wanted a 45ACP revolver and I was considering buying a 45ACP Mountain Gun, but overall, I'm happier that I can now shoot either. I wasn't going to cut the cylinder in my 25-5 in any case.>

How is it still possible to shoot 45Colt in this gun that you have cut the cylinder to accept clipped 45ACP? Won't you have excessive headspace for the original 45Colt cartridge? I have a 625-6 MG in 45Colt. While clipped 45ACP or 45AR brass will chamber and extract, you cannot close the cylinder with that brass. How does one machine the cylinder to fit 45ACP or AR and still get the firing pin to light off a 45Colt???.........safely, if at all!
 
I haven't tried 45ar but I have a couple of 625's cut for moon clips and they work just Great, 1 I just purchased here a month ago shoot's just as tight as either of my 25-2's and 625JM 4".

I have 7 N frames 2-625 mg, 2-25-2's and 3-625's for 45acp and 2 of the mountain guns have been cut, and accuracy isn't compromised one bit,If your looking to get one done by all means got for it, its great to have a MG with dual roles.

On the parts section of this forum you'll find someone selling 2-625 fluted cly., thats a good start to have a separate cylinder for the project and have the best of both worlds.


There's several gunsmiths you can get this work done from, just check this forum and you'll find a few, I'm sure a few of the guys here will chime in with some gunsmiths in mind, Just my 2 cents worth.

Joe
 
tdan said:
How is it still possible to shoot 45Colt in this gun that you have cut the cylinder to accept clipped 45ACP? Won't you have excessive headspace for the original 45Colt cartridge? I have a 625-6 MG in 45Colt. While clipped 45ACP or 45AR brass will chamber and extract, you cannot close the cylinder with that brass. How does one machine the cylinder to fit 45ACP or AR and still get the firing pin to light off a 45Colt???.........safely, if at all!
Click to expand...

Sir, as I understand it, such conversions are cut out only enough for a full-moon clip. That is, they're cut deeper on the inside (ratchet side) of the chambers to accommodate the clips and leave the cylinder full length at the outside. .45 Colts headspace on the remaining outside "lip," so to speak, while full-moon-clipped .45 ACPs are allowed to drop in deeper. The old WWI half-moon clips do not work in such conversions.

I've seen photos of such conversions that would help explain this better than I'm doing, but I can't find one right off. Perhaps someone else can post one.

Hope this helps, and Semper Fi.

Ron H.
 
I had it done and I'm very happy with it, you have to have the cylinder cut were you have to use moon clips on both rounds to use the half clips.
 
The rim thickness left as an outter ring - to catch the .45 Colt's rim - will also catch the Auto Rim's thicker rim, preventing the cylinder from closing. That will be the same result as with an un-converted .45 Colt MG. Look at the moonclip conversion as only a means for shooting moonclipped .45 ACPs. Certainly, un moonclipped .45 ACPs will fit... but they won't be 'stopped' until they hit the deep .45 Colt cartridge case step. You'd have to borrow the long snout firing pin from an 1895 Nagant to reach the primers then!

I have two .45 Colt MG's, a -6 & a -7. I started reloading just for .45 Colts, over eight years ago. The ammo cost has always been high. I also have a 625JM for .45 ACP/AR. I won't be modifying my MG's.

Stainz
 
Thanks to Ron H and Stainz, I can now visualize this mod. Still seems kind of rinky dink, as the 45Colt case rim would only catch on a small part of the cylinder rim. Seems like a mod that will result in those clipped 45ACP rounds having to make a VERY LONG run to the cylinder throats, and the 45Colt rounds kind of "drooping" down in the chambers due to lack of proper support. I would be surprised if a gun so modified would deliver any decent accuracy.
 
tdan said:
Thanks to Ron H and Stainz, I can now visualize this mod. Still seems kind of rinky dink, as the 45Colt case rim would only catch on a small part of the cylinder rim. Seems like a mod that will result in those clipped 45ACP rounds having to make a VERY LONG run to the cylinder throats, and the 45Colt rounds kind of "drooping" down in the chambers due to lack of proper support. I would be surprised if a gun so modified would deliver any decent accuracy.
Click to expand...

That's what I thought at first, but I haven't had any issues. Has anyone had accuracy problems? The only negative to me is that you can't shoot 45ACP rounds without moonclips, but I wouldn't necessarily do that often in a 45ACP revolver as you'd have to push them out anyways.
 
Why wasn't?

If this mod is such a good idea why hasn't the factory done it?
 
BSA said:
If this mod is such a good idea why hasn't the factory done it?
Click to expand...

At least 95% of all of corporate America is fully infected with NIH (Not Invented Here). If they didn't think of it, they ain't a'doin' it.

In addition, and even worse is the fact that virtually all of corporate America is run by people that have MBAs. The MBA program teaches them that you don't try to please all your customers, only the majority. That leaves a whole lot of us out in the cold, but they don't seem to notice.


Cat
 
I had the same conversion done to the same gun: a 625-6 MG in 45LC. I have had no problems in shooting 45LC and no accuracy problems with .45 ACP. Glad I did it as I cannot find 45LC locally.

Am I correct in my assumption that this modification reduces the value of the gun if I am ever so dumb as to want to sell it? (I think that I have ultimately regretted selling any of my guns, with the exception of a Kahr 9mm that ..., well, never mind).
 
Here is a conversion done a while ago on a 625-6 mountain by Pinnacle.
I'm very pleased with the conversion
I would only do it on a newer piece like this with the tight .452 throats


2051S_W_cyl_cut.JPG


2051S_W45CMtnClips1.jpg


2051S_W45CMtnClips3.jpg
 
Can somone explain the history behind the change in chamber throat size in 45ACP revolvers? I use to know this but I am fuzzy on it now...
 
Jeffery,

No drop in value to me, I can tell you that.

Oh wait, yea, no, that's it, I'll give ya $300 for it, yea, that's it. :)

Thanks for the pics Grinder. Can you post one of two or three .45 Colt cartridges chambered too please?


Cat
 
A bit of history on the .45 Colt cartridge and chamber.

It was introduced in the M1873 Colt Single Action Army revolver and adopted by the US Army.

Being a black powder cartridge, it was determined that chamber and throat tolerances would be on the "loose" side for reliability in sustained fire (combat) situations. 0.454" bullet, throat, and bore diameters were on the slightly generous side to allow for accumulation of firing residue and to allow for continued firing under conditions that did not allow immediate cleaning and lubrication. Chamber throats will routinely be found to be 0.456" and LARGER in both Colt and S&W products in .45 caliber. This was a routine production expedient during the black powder cartridge era (1870s thru WWI).

During WWI, S&W N frame revolvers were adapted from the previously chambered .45 Colt to .455 British caliber for British Army requirements. .45 Colt throat, bore, and groove diameters were used because they were very close to the .455 specifications.

When the US Government assumed control of S&W M1917 revolver production, it was determined that .45 ACP proof pressures were significantly higher than that of the previously chambered .455 cartridge. Because of the urgent need for M1917 service revolvers, the decision was made to make chamber throats to the previous .45 Colt and .455 British dimensions, namely 0.454"-0.456". This resulted in two things: increased combat reloading ease, and ability to pass the required .45 ACP proof test without the increased strength of heat treated cylinders.

In a nutshell, that is why S&W revolvers chambered in .45 ACP seemingly have oversized (.45 Colt sized) throat diameters.
 
If Grinder did it, it must be good idea.

How does it shoot with .45 ACP and .45 Colt? Can you tell the difference while firing, point of impact, recoil, etc.?
 
Back in the early '90s, I had it done to a 25-7, 2 625's, a Redhawk, an Anaconda and a 629 that we first rebored to .45 Colt. The idea came to me when I saw that a gunsmith was moonclipping 629s. This was before the factory was moonclipping N frames for rimmed cartridges. I asked the late Art Leckie, Austin Behlert's son-in-law, to do the milling. They all came out perfectly. Point of impact was always the same, given that the bullets were exiting with the same velocity.
 
You must log in or register to reply here.

Similar threads

B
S&W Model 22 of 1917
Replies
7
Views
6K
smokey04
S
H
.45 auto rim in .45lc
Replies
14
Views
12K
Gun 4 Fun
G
T
Casual Target Revolver Advice
2
Replies
37
Views
6K
one eye joe
one eye joe
W
.45LC and manufacturers vs. reloads
Replies
12
Views
3K
VAdoublegunner
VAdoublegunner
H
1917 Conflicting Answers!?
2
Replies
28
Views
5K
dsf
D

Latest posts

Back
Top