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Post by flyfisherman246 on Jun 28, 2021 3:53:54 GMT -5
I have read Lee's articles on his caliber conversions and he always starts with annealed steel for the cylinders. He then does all the machine work including reaming and then hardens the cylinder. I have never built a revolver cylinder so I'm not at all speaking from experience but isn't there a potential for warping, stretching, and contracting especially with the thin walls and being quenched after being red hot? Not to mention all the scale left behind that needs to be polished off. To me it would seam like if precision was the end goal here, all this machining work would want to be done after the cylinder is at its final hardness. Like I mentioned I have never done this before, but there has to be a reason some guys are starting with annealed steel. The HSS reamers will cut 42 RC just fine and carbide can be used if needed for turning, facing, and drilling operations if necessary. Thanks for the help.
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shorty500
.327 Meteor
too many dirty harry movies created me!
Posts: 905
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Post by shorty500 on Jun 28, 2021 4:40:19 GMT -5
Properly processed the most popular steels for cylinders distort, warp, bend or scale very little if any during heat treat. And all that is needed is slightly honing for final fitting & throat diameter control then polishing
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Post by Lee Martin on Jun 28, 2021 9:46:17 GMT -5
shorty500 is correct. While heat treating schedules indicate shrinkage, they tend to be on the high side (very high side in fact). We work with 4140, 416, and 17-4PH and shrinkage, when it can actually be measured, is miniscule. We're talking a couple of ten-thousandths tops (0.0001" - 0.0002") Post heat treating, there's virtually no front to back reduction. Fit to the frame isn't compromised. And if there was material shrinkage, the bolt would no longer fit the stop. We cut our notches to precisely match the bolt. The only areas which do show a little shrinkage are the base pin hole and throats (and that's more surface scale rather than dimensional shifts). Post furnace/quenching, the pin still slides through the cylinder but has a tiny bit of drag. So we hone that along with the throats. The latter is a must because we ream them undersized. Example - our .41 Magnums are bored 0.410", then honed to 0.4105" for bullets sized 0.410". Now you can certainly machine pre-hardened alloys. It just puts more wear on the tooling and creates a rougher finish. For that reason, we start with annealed, then harden as the final step. -Lee www.singleactions.com"Chasing perfection five shots at a time"
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Post by flyfisherman246 on Jun 28, 2021 10:47:41 GMT -5
Awesome, thanks for the quick replys. That makes a lot of sense.
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