Dan Wesson Moon Clip conversion - 9mm/38 Super or 38 Short Colt?

[Esoteria]

Hi guys,
I started this thread a couple of days ago opening up my quest for a 9mm or similar revolver for quick moon clip reloads. Lots of good advice was given.

I talked to Tom at TK Custom and he said he could convert Dan Wesson 15-2 cylinders to accept moon clips, and/or rechamber for 9mm or .38 super.

So I have 3 options I'm trying to decide between:

1. ($150) modify for moon clips, use .38 Short Colt when fast reloads are desired. .357 / 38 Special otherwise.
2. ($300) rechamber for 9mm moon clips
3. ($300) rechamber for .38 Super and still use 9mm most of the time, but have the extra flexibility. (I can do this, right? Only relevant difference for revolvers I saw in the SAAMI spec was the case wall thickness, which should be "close enough")

There's also a pretty stout cost for the moon clips themselves, which I think I'm willing to pay but I'd like to get some feedback first. For instance, if I go 9mm can I use "any old" 9mm moon clips meant for S&W cylinders and the like (I'm assuming they have substantially the same chamber spacing)?

Now, as I understand it, the key advantage to going with 9mm or .38 Super is that you get thicker moon clips and more "wiggle room". This may also play into the moon clip cost because perhaps "cheap" moon clips are viable at those thicknesses whereas thinner ones are not.

I'd love to hear some experiences with either type, or with anyone who's had either procedure done by TK Custom or similar.

What do you guys think?

 

[Old Fuff]

The .38 Super is supposedly semi-rimmed ( .406 rim Dia./.384 body Dia. - straight case) while the 9mm Parabellum/Luger is rimless with a tapered case which is headspaced by the mouth of the case in a pistol. (.391 at the back, .380 at the front.) Both rounds use .356 Dia. bullets. Choose one or the other.

 

[rcmodel]

3. Maybe, maybe not.

As Old Fuff said, the 9mm is a tapered case .007" larger at the rear then the .38 Super.

I doubt you can get a 9mm to chamber in a properly chambered .38 Super cylinder.

(But, I have never tried it.)

That would be a question you should ask Tom at TK Customs to get a straight answer from someone who should know.

rc

 

[Esoteria]

Good point on the taper. I missed that. However I'm certain I've seen posts of people with 38 Super cylinders saying they regularly use 9mm. I guess the tolerances allowed for it in their case.

As you say, it's a question for TK Custom directly, so we'll see what he comes back with.

Looking into it some more, it seems that most people who have done this have caught flak for doing it in an automatic, where the 9mm is probably being headspaced by the extractor. That particular issue shouldn't apply here, though.

Even if the answer is no, that's not such a big deal. I like the idea of still being able to get "more punch" out of my modified cylinder on the days I want it, but in practice I doubt I'd ever want more than 9mm +P levels anyway.

... Then again, I should probably ask if +P is OK as well.

 

[Esoteria]

Tom got back to me:
"If they drop into the cylinder, yes" [it's OK to shoot 9mm through his .38 Super converted cylinders]

I wonder if there's anything as far as reloading 9mm I would have to do differently to make sure they drop in. I guess resizing in the 38 Super die might help. Anyway, it seems #3 is an option, though maybe still not the best one.

 

[jerkface11]

Is the gun strong enough for 9x21? If so chamber it for that and you can still shoot 9x19.

 

[Old Fuff]

"If they drop into the cylinder, yes" [it's OK to shoot 9mm through his .38 Super converted cylinders]

He's right of course, although that means the chamber is on the high side of allowed tolerances, and the 9mm cases will be fire formed to match the chamber and come out (more or less) straight rather then tapered.

Presuming for argument only, I can see using 9mm ammunition in an emergency situation when they're isn't any other option, but on a regular basis - no.

 

[Esoteria]

@Old Fuff
Fair point, although given the number of other cases where fire-forming brass is a viable method for long term (and accurate) shooting, I feel like letting that happen and then resizing with 38 Super dies would be fine, IF it works, which it might not given the 9mm case head may prevent easily sizing down that ~0.007" (depending on the exact dimensions of the die, of course).

The more I research this the more I think it may be a moot point. 38 short colt seems to be such a viable option for competition (with the appropriate, and expensive, moon clips) that I'm finding it difficult to justify the 9mm option anyway unless I go the 9x21 or 9x23 route like jerkface11 suggested, which, if it can be done, seems like a way safer option than 38 Super if I want flexibility.

Dan Wesson barrels, especially VH ones, are at a premium now. Upwards of $400 for the barrel assemblies, so a $600 gun is a decent deal if it is in good condition and has a VH barrel on it, meaning about $800 after the mod for the whole kit, and that's a used (although awesome) gun. Makes me wonder if I should just buy a 627 V Comp at ~$1200 new and be done with it.

 

[Jim K]

If you want to use clips with any revolver, you need to do so in a way that the cartridge support against the firing pin blow) is NOT on the clip. In other words, the case should be supported on its rim (.38 Special, .357, .38 SC or .38 Super) or on the case mouth (9mm Luger, .380 ACP) not being held by the clip. The reason is that clips are springy and don't give proper support, so you can get inconsistent firing pin blows and inaccuracy or, at worst, misfires.

Jim

 

[Esoteria]

@Jim K
Excellent point, thanks. I hadn't really considered that, and it's one more ding against trying to use 9mm in the .38 Super cylinder. Sure, it'd probably work most or all of the time, but since 9mm would be my primary choice, it seems like an unnecessary risk.

Still though, I've seen a bunch of posts where a cylinder was chambered for 9x23 or similar and 9x19 was used, but I guess they're just taking the risk. I would speculate that it's not the material of the clip that's the problem (or else the soft brass case being used to headspace in auto cartridges would probably be worse than spring steel), but that there's some "room" left between the clip and cylinder face that could cause damping when the firing pin hits.

All useful and interesting input. Thanks

 

[rcmodel]

If you want to use clips with any revolver, you need to do so in a way that the cartridge support against the firing pin blow) is NOT on the clip

Not sure I buy into that theory.

The modern S&W .45 ACP revolvers are chambered to deeply to be reliable when fired without moon clip support.

So, the moon-clip is all that is supporting the case to insure reliable ignition.

And they seem to be totally reliable when used with moon-clips.

So it seems to me they headspace on the moon-clips.
Not on the case mouth

rc

 

[Esoteria]

It's true that on my 325 I've had many more light primer strikes without moon clips, but I assumed that was due to my own reloads' very wide tolerances in case length.

 

[WC145]

If you want to use clips with any revolver, you need to do so in a way that the cartridge support against the firing pin blow) is NOT on the clip. In other words, the case should be supported on its rim (.38 Special, .357, .38 SC or .38 Super) or on the case mouth (9mm Luger, .380 ACP) not being held by the clip. The reason is that clips are springy and don't give proper support, so you can get inconsistent firing pin blows and inaccuracy or, at worst, misfires.

Jim

@Jim K
Excellent point, thanks. I hadn't really considered that, and it's one more ding against trying to use 9mm in the .38 Super cylinder. Sure, it'd probably work most or all of the time, but since 9mm would be my primary choice, it seems like an unnecessary risk.

Still though, I've seen a bunch of posts where a cylinder was chambered for 9x23 or similar and 9x19 was used, but I guess they're just taking the risk. I would speculate that it's not the material of the clip that's the problem (or else the soft brass case being used to headspace in auto cartridges would probably be worse than spring steel), but that there's some "room" left between the clip and cylinder face that could cause damping when the firing pin hits.

All useful and interesting input. Thanks

I've read both of your threads on this subject and, frankly, it sounds like you should buy a 986 and have it Cerakoted and call it a day.

However, if you insist on going the conversion route it's not the big mystery or problem child that some would lead you to believe, Jim K's comments above are a perfect example. The moonclips sit flush against the cylinder face, there isn't enough impact energy from a firing pin strike, nor are moonclips so thin, to cause the sorts of issues he's describing. I've been carrying and shooting a Pinnacle modified S&W 360J for going on 8 years now with zero issues shooting 9mm in moonclips even thought the chambers are cut for 9x23. I've shot 9mm, 9mm Largo, .38 Super, and 9x23 Winchester through my gun and it functioned perfectly with all of them. If you check the S&W forum you'll find plenty of people that have had the same conversions done on their guns by both Pinnacle and TK Customs with no problems or adverse effects.

 

[gotboostvr]

RC, My 625JM-8 has been perfectly reliable with or without moonclips in 45acp, even with my mixed headstamp reloads.

 

[rcmodel]

That's good for you.

My shooting buddy's 625-? JM is totally unreliable without moon clips with anything he puts in it.
As is my 625-6 Mountain Gun.

Maybe S&W got the message, and started chambering them right again??

Like they always did the first 80 years they made .45 ACP Revolvers.

rc