Colt SA chamber wall thickness

[Malamute]

I googled around but I didn't find the details I was looking for. Does anyone have actual Colt or repro SAA's outside chamber wall thickness and the wall thickness at the bolt cut (or depth of the bolt cuts)?

[Daisyman]

Does it make a difference in the caliber? I've got a Beretta Stampede in 45 LC I could measure, but I'm not sure that would be relevant to what you want. Couldn't different manufacturers make each to their own specs? Bolt cut? Sorry, I guess I'm not following. Bolt sounds like a rifle.

[pshort]

Howdy,
"Bolt Cut" is the notch that the "bolt" comes up into to hold the cylinder from turning....
Varies a lot... On my Rugers, the notch is offset from the chamber so it's not an issue...
Hope that helps....

Paul

[Malamute]

I'm trying to learn the thickness of the Colt SAA 45 colt cal chamber wall and at the bolt cut and see if my idea is workable for a project in mind. The first numbers I found are REALLY thin at the bolt cut for standard Colts, and the wall thickness is also a bit less than I expected, though I haven't really compared to other types much.

[Griff]

He's talking about where the bolt comes up into the cylinder to lock the cylinder. I don't have one with me to measure, but on a 45 Colt, they're pretty thin.

[JerryB]

I have a 1958 Colt SAA .45 in the safe, I'll get it out and have my grandson do some measurements.

[Malamute]

Great, thank you!

I have a percussion conversion idea, and am trying to figure out if my conversion cylinder would work if rechambered to 41 long colt from 38 S&W. It would allow proper sized bullets for the groove diameter of the percussion barrel to be used. I have a 150 gr 38-55 mold that throws bullets at about .379.

The conversion cylinder I have is on old one, I don't know when it was made. If I can make this work, great. I cant really afford to buy anything, so am trying to figure out if its worth fooling with. Most of the conversions seem to suck money up at a prodigious rate. That's not in my budget. This is a shoestring operation. Have an 1861 36 that's been worked over to remove the shoulder stock cuts and most of the markings, all the blue gone, and no loading lever. The percussion cylinder has too large of a gap to be practical, but the conversion cylinder would work. Groove diameter is about .378. I came into it several years ago from somebody that gave up on the project. Its about useless as is.

Somebody does complete conversions to 41 Colt and says they work fine with hollow base bullets. In this case, the bullet Id use would actually fit the bore, not be oversize like the commercial conversion.

[JerryB]

Malamute, the measurements we got are .058 for the wall and .035 for the bolt depth. hope this helps.

[Leverluver]

As I'm sure you know, after the change to inside lubricated, the bullet was a .386. Whether the sizer die will squish things down enough to hold a .378 bullet will be interesting. Maybe a special order Lee FCD would be enough, maybe not. I don't think I would want to squeeze the whole case down another .008" unless you were going to reduce the chamber diameter that much also, otherwise the smaller cartridge would rattle around in the chamber. So you're talking a lot of custom dies and/or reamers. Like you say, the conversion has already been done (hoofhearted??) so why the concerns?

[Mike Hunter]

I have not seen any specific data on wall thickness, I have however read data on minimum and maximum cylinder OD. I will try and find it for you. I believe that the data was for the .45 LC.

Mike

[M. M. Wright]

Kuhnhausen's book gives cylinder dia. (this is for Colt 1st or 2nd gen) as nominally 1.650. The chambers are located on a radius of .530 from the center axis. 45 Colt chambers are a max of dia. .490 so half of that added to the .530 is .775 subtracted from the cylinder radius of .825 leaves .050 of material for the wall thickness. I'm using worse case tolerance build-up so you could find more on most examples.

The bolt cut can be .045 deep so there is not much left. A smaller chamber and a shallower bolt cut would give a little more but not much.

Look at what you can get from Kirst. I just finished an 1860 Army conversion with one of their cylinder/back plate with loading gate that is a really neat 5 shooter. No way I could cobble up the parts for what they get for them. ($325)

I once replaced the cylinder in a 1st gen Colt to make it a 45 ACP. The new cylinder bulged the locking bolt cuts and took quite a bit of pounding to get the empties out. They replaced the cylinder with no questions and all was well thereafter. I was in the army and could get the 45 ACPs free from post AMU.

[Hawkeye2]

You have a .38 S&W conversion for the '51/61 /colt Navy, is it one of the old "Legal Defender" conversion kits from the 70's? They came out of Conyers, GA and seem to bring quite a price on eBay considering they only sold for about $35. They came complete with the cylinder, conversion ring & firing pin assy., screws, drill & tap, a temporary spacer ring to locate the conversion ring and an extension tube to epoxy to both the driii and the tap to get you down past the cylinder arbor as well as a full set of instructions. The only markings on those were ".38 S&W ONLY" on the cylinder and the conversion ring was held to the recoil shield by 2 countersunk screws. First you might want to check the length of the cylinder to see if it will take a .41 colt, it should be OK. You have to open the forcing cone and then the barrel is close enough to take .41 Colt inside lubed rounds with dead soft lead but not the old outside lubed heel base round. Before you get into a lot of work why not just make it up with the cylinder as is and shoot .38 S&W? If you aren't happy with it you can always convert it later.

If you need more info or want the cylinder chambered I suggest Hoof Hearted (Gary Barns) as he is probably the best and most knowledgeable person on cartridge conversions in the country. Don't be afraid to call him as he will answer all your questions too. He does rechamber conversion cylinders to .41 Colt.

http://www.cartridgeconversion.com/Home_Page.php

You can also check out the CAS City forum for more information on the conversions and ask questions there.

http://www.cascity.com/forumhall/

[Malamute]

Yes, that's exactly what I have. I've had it for years and never got the ambition to do the work, nor had a gun I wanted to try it on. The difference in bullet diameter vs bore never inspired confidence it would ever shoot very well, and reports I've seen seem to indicate that is true. To me, it isn't worth doing just to do, if it isn't going to shoot fairly well (like useful for small game). Id thought of other ways to get a proper sized bullet in it, but I recently saw the 41 colt conversion and figured mine may be usable in a 41 conversion. "Just buy....." isn't part of the equation. If it isn't possible to use what I have at minimal cost, I cant do it, I just cant afford projects for fun at this point. I can do the install of the kit, and could probably manage the rechamber and throat with friends tools, and perhaps a rental chamber reamer. Beyond that, its out of my budget by a mile. If I could afford one of the better conversion kits Id likely just buy a different gun that didnt need a kit and that id enjoy shooting. The entire project is in the "interesting, but not important" classification. Conversion guns are interesting, but not anything I feel is a priority to me.

The gun I bought several years ago. It was cheap as a half done project missing parts (loading lever assembly) and unusable in its present condition. If it wont make up into a conversion, its not really of any use to me.

So far, with the info I have, I think this cylinder would work OK if rechambered for 41 Colt. I believe the walls are thick enough, particularly with the loads appropriate for a conversion gun. It may shoot OK with hollow base wadcutters in 38 S&W cal, which would be relative simple. Ive seen some info about that in searching for information about conversions.

Thanks for all the information guys!

.

[Malamute]

As I'm sure you know, after the change to inside lubricated, the bullet was a .386. Whether the sizer die will squish things down enough to hold a .378 bullet will be interesting. Maybe a special order Lee FCD would be enough, maybe not. I don't think I would want to squeeze the whole case down another .008" unless you were going to reduce the chamber diameter that much also, otherwise the smaller cartridge would rattle around in the chamber. So you're talking a lot of custom dies and/or reamers. Like you say, the conversion has already been done (hoofhearted??) so why the concerns?

Yes, if a regular 41 Colt die will size the shell enough to hold the .379 bullet is a question. Does anyone load 41 long Colt with inside lubricated bullets? Have you ever checked the ID of a sized but not expanded case?

Yes, the conversion has been done before, the concern is if the cylinder I have will have enough chamber wall to work with 41 Colt. I don't know what diameter cylinders Gary Barnes uses. I guess a note or call to him would yield that information. In any event, with whats been provided about standard 45 Colt wall thickness, mine is right at about the same wall thickness if opened to 41 Colt size I believe (did the measurements a couple days ago). I believe I came up with .015" thickness at the bolt cut if opened to 41 Colt with minimum chamber size.

[Leverluver]

Interesting project in any case, made more so as I also have one of those 38SW cylinders from decades ago. I'll have to go dig it out and take a second look at it. Have fun with it.

[M. M. Wright]

You could always just put a liner in the barrel.

[Malamute]

You could always just put a liner in the barrel.

True, though that would likely put the project out of my practical budget limitations. As I mentioned before, its in the "interesting, but not important" category. If I can do the majority of the work without much extra expense, I'll do it. At this point, I'm selling things to pay bills and buy things I need like tires. This is a distraction project, not anything I can afford to spend money on. I may end up selling it as a project to help pay bills.

Forgot to mention earlier, I think I may be able to modify a Ruger loading gate and adapt it to the conversion back plate. The part is cheap, and if I can shape it with the tools I have, it may work.

The donor (victim?) gun is a Pietta 61 navy.