Post by tinkerpearce on Sept 8, 2017 10:22:03 GMT -5
I thought it probably best to reassure you all at this point that I will be proceeding with caution. After advice and due consideration I have shelved the idea of using Red Dot powder for this cartridge, and will be working up loads with Trail Boss. This is a much more forgiving powder and has yielded good results in my short-barreled .38 S&W. I am doing this for fun, and my definition of that quality does not include detonating things that I hold in my hand!
Regarding the gun I am using- despite it's age the gun was apparently in un-fired condition when I got it. Detail stripping it revealed no residual powder fouling or wear on any of it's components. Owing to my profession I have a fair bit of metallurgical knowledge and have examined the gun carefully. The cylinder appears to be a mild steel, 1018-1020 or it's equivalent. It is quite soft but also very thick, and this material in this condition has high elastic limits. I will be doing chamber castings as I work up to more powerful loads and at the first sign of stretching or other issues I will shelve this cylinder and go different route. The arbor tests at around HRc40, indicating that it is tempered steel of an appropriate hardness. The frame exhibits qualities similar to half-hard spring steel; I have my doubts that it is actually case-hardened. If I don't go nuts it ought to be up to the job, but again at the first sign of issues it's over.
My reason for basing this conversion on the ASM cylinder is simple- I've got it and rather than turn it into paper-weight why not try it? At very least I'll learn something, and I can always toss it and go a different route if it isn't working out (or I screw it up.) My original plan was to use a Kirst cylinder, and I will revert to that plan in a heartbeat at the first sign of trouble. Alternatively I might buy some 4140 round stock and attempt a scratch-built cylinder. I've never done this, but it should be within the limits of my skills and equipment and I will almost certainly try it eventually, if not for this project then another down the road.
Anyway I just wanted to reassure you all that I am actually thinking about this and trying to exercise due diligence.
Regarding the gun I am using- despite it's age the gun was apparently in un-fired condition when I got it. Detail stripping it revealed no residual powder fouling or wear on any of it's components. Owing to my profession I have a fair bit of metallurgical knowledge and have examined the gun carefully. The cylinder appears to be a mild steel, 1018-1020 or it's equivalent. It is quite soft but also very thick, and this material in this condition has high elastic limits. I will be doing chamber castings as I work up to more powerful loads and at the first sign of stretching or other issues I will shelve this cylinder and go different route. The arbor tests at around HRc40, indicating that it is tempered steel of an appropriate hardness. The frame exhibits qualities similar to half-hard spring steel; I have my doubts that it is actually case-hardened. If I don't go nuts it ought to be up to the job, but again at the first sign of issues it's over.
My reason for basing this conversion on the ASM cylinder is simple- I've got it and rather than turn it into paper-weight why not try it? At very least I'll learn something, and I can always toss it and go a different route if it isn't working out (or I screw it up.) My original plan was to use a Kirst cylinder, and I will revert to that plan in a heartbeat at the first sign of trouble. Alternatively I might buy some 4140 round stock and attempt a scratch-built cylinder. I've never done this, but it should be within the limits of my skills and equipment and I will almost certainly try it eventually, if not for this project then another down the road.
Anyway I just wanted to reassure you all that I am actually thinking about this and trying to exercise due diligence.