Another "9"60

[pred]

BHP, if you have an older J frame, Bring it along and size up the cylinders by eye, You will see a difference in the two if it's a magnum size cylinder.
Peter

 

[azdover]

I have some questions:

1) Did you have to rebarrel the gun to shoot 9mm?

2) Is that cylinder that you picked up the same one for a S&W 940?

3) Is the timing hand also for a 940?

4) I don't know much about J-Frames, but can the same cylinder and timing be used any J-Frame revolver?

I am interested doing the same rechambering on a J-Frame (60, 640 or 649).

Thanks in advance.

I am not a gunsmith and make no claims to having any expertise, but if you're interested, this is how I successfully converted my Model 60 no dash to shoot 9MM using a new style 940 cylinder. In my particular case, I found a lot of the info in this thread very useful.

http://smith-wessonforum.com/s-w-revolvers-1980-present/109629-640-940-conversion.html

#1 Like pred said, I'm still using the original Model 60 barrel. From what I understand, and I'm not claiming to be any kind of expert - I can't even say I slept in a Holiday Inn Express last night - the 9MM round is slightly smaller in diameter than a 38 Special, but not enough to really affect accuracy at the ranges I'd expect to shoot a J frame snubby, 10-15 yards at the most.

#2 I bought my cylinder from Brownells - 940 cylinder new style -$123.68 SKU#: 940-000-760 (Should include the extractor - mine did). The new cylinder is the same size (diameter and length) as the one in my 940 no dash.

However, I tried the cylinder from my 940, and it would not fit in my Model 60 without removing some metal from the base of the extractor around the center pin, which I did not want to do.

The 940 cylinders are in stock according to Brownells website as of 29 Dec. I had an old extractor rod and spring, plus an old center pin and spring, so I used those parts with the new 940 cylinder. If you don't have those extra parts, try Brownells again.

Extractor rod - $10.31 SKU#: 940-070-660

Extractor spring -$1.60 SKU#: 940-075-790

Center pin - $7.66 SKU#: 940-000-853

Center pin spring -$1.61 SKU#: 940-070-630

I had to shorten the extractor rod a little so the cylinder would open and close properly. I also had too much cylinder endshake and the front of the cylinder was rubbing on the back of the forcing cone, so I added 3 x .002 cylinder bearings. That took care of the end shake and left a b/c gap of .006. Lock up is now nice and tight while still allowing the cylinder to rotate freely. And you guessed it, you can get the bearings at Brownells.

Power Custom cylinder bearings - $17.99 SKU#: 713-100-001

#3 I had to buy a new timing hand to work with the new style 940 extractor. It was a little bit longer than the original in my Model 60. Again, another Brownells part - Hand - $17.80 SKU#: 940-212-330. It is listed for the 940, but also showed it worked in a bunch of other J frames that shot the 38 and 357. I found that the original shorter timing hand would not advance the 940 new style cylinder far enough to lock up during double action firing. Suprisingly, I found the longer timing hand would not advance the old style Model 60 cylinder to lock up during single action firing, but would during double action. So, I have to change both the cylinder and timing hands when I want to switch calibers. The one on the left is the longer timing hand.

#4 No. The 940 cylinder I used was about the same length as my original Model 60 cylinder. But I found it was about .10 inch shorter than the cylinder in my 649-3 which shoots 357. I also checked some other later model J frames that shot only 38, and found that they have the longer cylinder also. So it appears to me that the new style 940 cylinders currently available from Brownells aren't going to work in the later J frames without some major gunsmithing and dollars, if at all. In the following picture, you should be able to see that the 940 cylinder on top is shorter than the 649 cylinder.

Another clue that this a J frame with a longer cylinder is the reinforcement strap on the left side of the frame on the back of the cylinder window. All of the later model J frames I've seen have that extra metal.

In order for me to fit the longer timing hand and the new style 940 cylinder, I got my big clue from headknocker. I had to file the trailing ends of the ratchet. Before filing, the cylinder would advance and lock up on 3 of the charging holes properly during double action cycling, but would bind while cocking single action on all 5.

I loaded 5 empty cases in a moon clip into the cylinder to make sure the ratchet was properly aligned. Some of the extractors may have a little play in them and that may affect carry up, preventing proper timing and cylinder lock up. The empty cases should take out most if not all the play. The old style extractor used 2 pins to make sure everything lined up.

With the cylinder closed and cylinder lock engaged, I looked through the rear of the frame and could see the trailing edge of the ratchet through the timing hand slot (3). I took a fine tipped Sharpie and marked the edge of the ratchet along the left side of the timing hand slot. The part of the ratchet that controls the timing of the charge hole alignment with the barrel is the lug at the charge hole's 5 o'clock position when the charge hole is lined up properly with the barrel (3). You can see the hand (1) just below the lug (2) of the next charge hole ready to advance the cylinder in the following picture.

Using the Sharpie mark as a rough indicator of how much metal I had to remove, I used a small fine flat file with a smooth edge on the bottom and slowly filed that trailing edge, removing only a little bit of metal at a time. All of the lugs were about .130 inches before filing. After filing, they were about .100 inches plus or minus a couple of thousanths. I reassembled the gun completely except for the yoke screw. Then I would file a few strokes, refit the yoke and cylinder into the frame, check for proper carry up and lock up in both double action and single action, then file again if necessary. As I got closer to the proper clearance, the gun would work properly double action with no resistance. In single action, I found I could finally cock the hammer even though I felt some resistance. I continued to file the lug a little at a time until there was no resistance while cocking the hammer single action. I made sure to file parallel to a line running from the center pin to the middle of the proper charge hole while keeping the file as close to perpendicular to the back of the cylinder as I could. Here's a picture of the file I used and the cylinder plus file.

Here is a comparison of the the extractors on the old and new style cylinders. You should be able to see the different shape the lugs on the extractor. The old style appears more rounded, while the new style looks a little more tear dropped shaped to me. The first is the Model 60 old style. The second is an uncut new style extractor. The third picture is the new style extractor I fitted. Ignore the dimples in the face of the extractor. This was my test piece I found cheap at a gunshow. Suprisingly, the dimples don't affect function at all. Hopefully, you can see where I removed the metal from the trailing edges of the lugs. "IF" you file off too much metal, all is not lost, you can get another extractor from - you guessed it again - Brownells! And no, I don't work for them or get any kind of endorsement

My orginal Model 60 extractor

Brownells new style before filing and fitting

Filed and fitted new style (with light weight holes - just kidding) Note metal removed from trailing edges of lugs. This was my test piece. It still worked fine even with the extra dimples. AGAIN - I did NOT add the dimples - they were there beforehand - and suprisingly, did not affect function in any way after the extractor was fitted.

Finally, the finished product before reinstallation in the gun. I numbered the charge holes just to help me keep track of which ones were working properly

So far, I've put about 75 rounds through my 960 with no problems. It's still finicky about which ammo it likes, but not as much as my 940. I find Remington works great and ejects smoothly. Federal and Winchester work okay, just takes a firm push on the ejector rod. Blazer Brass normally takes a real firm whack with a rubber mallet, so I avoid that now. The gun shoots about an inch and a half low at 10 yards, so I may have to file the front sight down a little. It shoots pretty much right on in azimuth.

Hopefully, this long post will help answer more questions than it raises. I found almost all this info by searching through the S&W forums, and owe a lot of thanks to other guys like WC145, Safearm, Headknocker and Pred who posted up their results before I did. My apologies to anyone else I'm sure I missed.

This worked for me - probably because I'm more lucky than skillful - hope it works for you.

Pete

 

[safearm]

Pete,
That was a great post! While I'm not in the market for another J-frame 9mm, I'll keep a copy of your post available in the off chance I decide to build one for myself. The pictures and descriptions are very clear and I think even I could follow the steps.
P.S.- I haven't used any Blazer ammo in either of my guns. Both of them have polished chambers and so far, I've not had any extraction problems, which normally occur in the 940s.

 

[manny25]

very nice 9mms

 

[tekarra]

Pete,
Great post, thanks. I sometimes think about doing that conversion so will keep your post handy if/when the iron is hot.

 

[HEADKNOCKER]

Great Pics Pete!!
I just got mine out of the safe & was looking at it after reading your post.. I too had to use a punch to swag some metal on my ratchet too, looks almost just like yours..
I saw another 642 No Dash Friday for $400 that could be the donor recipient of one of these 940 cylinders..
Great Write Up Too!!
Thanks
Gary aka Headknocker

 

[azdover]

Added some more pictures and updated text just to try to make things a little clearer (I hope).

Pete

pred - Nice Pinto!