How hard to cut a revolver for moonclips?

[aandabooks]

Let me start by saying I'm a machinist with access to the tools to do the job. I've watched the couple videos available on Youtube. I have no desire to screw up my S&W cylinder. The videos make it look easy but is it really?

The gun I'd be doing the job on is a S&W 686+ 7 shot.

[peterthefish]

If you're a machinist and you've watched TK custom's videos, you know exactly what's involved. So what's the question?

[aandabooks]

What is the oh-crap factor? If it were simple everyone with access to a mill and a rotary fixture would be doing it. Sometimes things that appear simple really aren't. I suspect that this is as simple as it looks but wanted other input from other people who have done this job themselves.

[peterthefish]

There isn't anything crazy to it (other than molesting a factory gun). I'm not sure I'd attack with without a CNC mill but I suppose you could. Just buy some Moonclips, mill out area under moonclip, move on. Get your cut depth right and you'll be fine.

[buckaroo45]

It's a leap of faith or "hold my beer and watch this" for most of us. Not so much for a few.

Now where'd I put my #10 bastard file ???????

Ron

Certified American Voter and Gun Toter

NRA Life

Yadda-Yadda

[EEH]

Have not had one done in a long time ,,But for what it used to cost ship it out it cones back right,no worries..

buckaroo45 ,,I keep my fine watch making tools in the bottom drawer..

[toothguy]

I watched Warren (Toolguy) do one sometime ago. He did most of the cut on his lathe then used the mill to remove the metal close to the ratchets (I think TK does all the cutting with the mill). The cut looked very smooth when he was finished.

Edited November 9, 2014 by toothguy

[Toolguy]

The lathe is the easy way to do it. I cut the extractor and cylinder together. Chuck the cylinder in the lathe and hold the extractor in with a live center. I use a boring bar with a small triangle insert with the boring bar parallel to the cross slide. It is very important to put something in the chambers to support the extractor during cutting, whether on the mill or lathe. I use either brass or Delrin turned to a light press fit. I cut the depression about .005 deeper than the thickness of the moonclip to allow for dirt or slight bows in the clip.

On rimmed calibers it is best to leave a rim around the cylinder for the brass to headspace on and also for the cylinder to be held forward by the frame lug. If the cylinder can go too far back when it's open, then it will be hard to close quickly. The .45 ACP guns have the frame lug further forward to account for this.

On some extractors the middle part is round. These can be done entirely on the lathe. On some extractors the middle is scalloped next to the ratchets. These have to be finished off on the mill to get the scallops cut out so the moon clip will seat. A 7/16 end mill is the right size for this job. This part is a little finicky on the setup because you have to come in and just kiss the original surface without getting into the ratchet. Once the first one is right you index the extractor and do each one in turn. Set a stop on the quill for depth and plunge cut. Make sure to deburr all parts involved and you're done.

Edited November 9, 2014 by Toolguy

[pyrrhic3gun]

+1 on what Toolguy says.

You can also do it all on the lathe by undercutting the extractor with the right shaped tool.

I just hold the cylinder and extractor assembly between centers that guide off the crane bore in the cylinder on one end and the center hole in the extractor on the other end.

With light cuts you can get it done just fine. Attached a pic of the way leaving some meat on the outside of the cut lets a rimmed cartridge still head space correctly, another of the undercut extractor, and a last one of the tool used to cut the extractor.

Take care on measuring the depth of your cut. Have fun!

[Toolguy]

Nice work P3! Good pics.

[aandabooks]

Thanks for the pics. I'll probably be doing this on one of my mills but the lathe is a good option also.

The other job I'm contemplating is champhering the cylinder on my 625. This seems a little more straight forward.

[PatJones]

I cut the chamfer on my 625 using a .500 counterbore. I located each chamber with a coaxial indicator. After touching off with the counterbore, I think I only brought the table up like .010 or .015. The chamfer only needs to be big enough to allow the edge of the crimped case mouth to not catch. If you go too deep with a .500 cutter a lip will form as you run out of cutter width.

[Tom Revo]

We can do it on our mill, with fixture in 10 minutes.

TK

[Boxerbill]

+++1 for TK customs