Big Cholla
Member
I have a couple of requests to run thru the procedure that I use when hand reaming 22 caliber cylinders for S&W revolvers. This works for me. Other pistolsmiths might use something different in technique:
I have a rotary head vise with one set of jaws padded with Brownells poly vise jaw liners. I use reamers for both calibers with the cutting shoulder for the rim of the cartridge built in to the reamer. Leave the ejector rod in place as well as the ejector star/extractor. Paint the surface of the ejector star with Dykem around each chamber. Paint the area recessed for the cartridge rim on each chamber with Dykem. I use the Red color because of a better contrast with blued parts and it also works well on stainless steel. I place 5 fired brass in 5 chambers. Then secure the cylinder horizontally in the padded vise pointed outward where you can stand with a good stance for pushing and place the cylinder at about the height of your pushing forearm when it is horizontal. Mount the reamer in a "T" handle that won't allow the reamer to turn in the handle. I use Mobil Cutting oil for both SS and steel cylinders. The couple of times I did aluminum cylinders, I used a cutting lubricant that is specific to aluminum. This job gets messy, so place old shop rags around, under and anyplace they need to be to catch cutting oil runoff. I use a thumb operated oil can for my cutting oil. Have a plastic bowl or cup to point the reamer into and oil it after you have oiled the chamber to be reamed. Every flute of the reamer must be oiled. Start the reamer in the chamber twisting to the right or clockwise. NEVER turn the reamer in reverse for any reason. Cut with constant pressure until shavings are visible at the mouth of the chamber or sooner if you wish. Ease off the pressure on the reamer and start pulling it backwards while continuing to turn clockwise. The reamer will resist the retraction for a few partial turns and then will come loose. Don't drag a cutting edge against any part of the mouth of the chamber. Clean the reamer and the chamber being cut. I use compressed air to clean both and a shop rag to catch the resultant chips and spray. You might use a common pistol patch mounted on a cleaning rod. Re-oil both chamber and reamer and repeat as necessary until the reamer's shoulder is getting close to the surface of the chamber/extractor that the cartridge rim rests against. Watch the Dykem color there closely while gently and slowly turning the reamer in. The instant you see a drag mark on that surface in the Dykem made by the reamer's shoulder stop pushing in and start pulling out. Again clean chamber and reamer. Turn the cylinder if necessary for the next chamber to be cut. Repeat these operations until all 6 chambers are reamed. I use a loaded factory cartridge that I paint with Dykem to identify it and to watch for burrs left inside the chamber for a "no-go gauge". After all chambers are cut, clean and dry with normal cleaning techniques. Then run the one 'no-go' cartridge into all chambers watching for complete seating of the cartridge. If in any chamber you note the cartridge not seating properly then re-ream that chamber being very gentle and careful. I have been known to load all 6 chambers with factory ammo and look carefully for any that are 'high'.
Note, it is of vital importance to almost surgically clean the reamer between uses. I know some smiths just wipe the reamer with a shop rag and then dip it into a jar of cutting oil. I have also seen some of their chambers left with a drag mark from a cutting chip having been left on the reamer. Don't cut the cartridge rim's seating surfaces of the cylinder/extractor any deeper than what they already are. Poor ignition and inaccuracy could result. When done disassemble the cylinder, taking out the extractor/ejector star. Clean everything and relube. Reassemble and place back into your handgun.
This job can be done by a precision machinist on precision equipment using a line bore procedure. It is time consuming and therefore expensive. I have never found an absolute necessity for doing it that way. I have never had a S&W 22LR or a 22 MRF shoot worse and most shot more accurate and one M 617 shot extremely more accurate after this cylinder chamber reaming to 22 MRF.
Of late, I have been reaming 22 LR cylinders for M 617s out to 22 MRF for a conversion caliber/cylinder. I have found the resulting accuracy for 22 MRF shooting thru 22 LR barrels to be startling good. I now have two M 617s one with 4" bbl./6 shot and one with 6" bbl./6 shot. I found an extra cylinder for both and after fitting to the frame reamed them both to 22 MRF. Both when shooting the 22 MRF are at least as accurate as the original 22LR and the 6" is more accurate.
If anyone has a specific question, please PM me and I will try to explain/answer as best I can. ............BC
I have a rotary head vise with one set of jaws padded with Brownells poly vise jaw liners. I use reamers for both calibers with the cutting shoulder for the rim of the cartridge built in to the reamer. Leave the ejector rod in place as well as the ejector star/extractor. Paint the surface of the ejector star with Dykem around each chamber. Paint the area recessed for the cartridge rim on each chamber with Dykem. I use the Red color because of a better contrast with blued parts and it also works well on stainless steel. I place 5 fired brass in 5 chambers. Then secure the cylinder horizontally in the padded vise pointed outward where you can stand with a good stance for pushing and place the cylinder at about the height of your pushing forearm when it is horizontal. Mount the reamer in a "T" handle that won't allow the reamer to turn in the handle. I use Mobil Cutting oil for both SS and steel cylinders. The couple of times I did aluminum cylinders, I used a cutting lubricant that is specific to aluminum. This job gets messy, so place old shop rags around, under and anyplace they need to be to catch cutting oil runoff. I use a thumb operated oil can for my cutting oil. Have a plastic bowl or cup to point the reamer into and oil it after you have oiled the chamber to be reamed. Every flute of the reamer must be oiled. Start the reamer in the chamber twisting to the right or clockwise. NEVER turn the reamer in reverse for any reason. Cut with constant pressure until shavings are visible at the mouth of the chamber or sooner if you wish. Ease off the pressure on the reamer and start pulling it backwards while continuing to turn clockwise. The reamer will resist the retraction for a few partial turns and then will come loose. Don't drag a cutting edge against any part of the mouth of the chamber. Clean the reamer and the chamber being cut. I use compressed air to clean both and a shop rag to catch the resultant chips and spray. You might use a common pistol patch mounted on a cleaning rod. Re-oil both chamber and reamer and repeat as necessary until the reamer's shoulder is getting close to the surface of the chamber/extractor that the cartridge rim rests against. Watch the Dykem color there closely while gently and slowly turning the reamer in. The instant you see a drag mark on that surface in the Dykem made by the reamer's shoulder stop pushing in and start pulling out. Again clean chamber and reamer. Turn the cylinder if necessary for the next chamber to be cut. Repeat these operations until all 6 chambers are reamed. I use a loaded factory cartridge that I paint with Dykem to identify it and to watch for burrs left inside the chamber for a "no-go gauge". After all chambers are cut, clean and dry with normal cleaning techniques. Then run the one 'no-go' cartridge into all chambers watching for complete seating of the cartridge. If in any chamber you note the cartridge not seating properly then re-ream that chamber being very gentle and careful. I have been known to load all 6 chambers with factory ammo and look carefully for any that are 'high'.
Note, it is of vital importance to almost surgically clean the reamer between uses. I know some smiths just wipe the reamer with a shop rag and then dip it into a jar of cutting oil. I have also seen some of their chambers left with a drag mark from a cutting chip having been left on the reamer. Don't cut the cartridge rim's seating surfaces of the cylinder/extractor any deeper than what they already are. Poor ignition and inaccuracy could result. When done disassemble the cylinder, taking out the extractor/ejector star. Clean everything and relube. Reassemble and place back into your handgun.
This job can be done by a precision machinist on precision equipment using a line bore procedure. It is time consuming and therefore expensive. I have never found an absolute necessity for doing it that way. I have never had a S&W 22LR or a 22 MRF shoot worse and most shot more accurate and one M 617 shot extremely more accurate after this cylinder chamber reaming to 22 MRF.
Of late, I have been reaming 22 LR cylinders for M 617s out to 22 MRF for a conversion caliber/cylinder. I have found the resulting accuracy for 22 MRF shooting thru 22 LR barrels to be startling good. I now have two M 617s one with 4" bbl./6 shot and one with 6" bbl./6 shot. I found an extra cylinder for both and after fitting to the frame reamed them both to 22 MRF. Both when shooting the 22 MRF are at least as accurate as the original 22LR and the 6" is more accurate.
If anyone has a specific question, please PM me and I will try to explain/answer as best I can. ............BC
Last edited: