Help with K32 Masterpiece cylinder pin

[444 Magnum]

I just received a post-war K32 masterpiece made (forged?) in 1948. I also have a K38 masterpiece from the same time period that I am using for comparison.

The action of the K32 works fine except for the cylinder release. After a couple of cylinder open/closings, it will lock up. I think what is happening is the cylinder pin is too long and is causing the bolt pin (terminology may be wrong) to become unseated from the hole. Since the bolt pin is unseated, the cylinder release locks and fails to open the cylinder. I have to take the side plate off, remove the hammer and bolt/plunger assembly and manually push the cylinder pin back in to release/swing the cylinder open.

Here are pictures of the cylinder pin from both pistols. The K32 is K 660xx (late 1948) and the K38 is K 778xx (early 1949). Probably both assembled and shipped in 1949.

The K32 cylinder is on bottom in the picture and the pin is the longer of the two.

This is the entire cylinder pin length for the K38.

The same for the K32.

Here's a picture with the cylinder closed and the bolt/plunder assembly removed. There isn't much room for the bolt to seat.

Both of these pistols are above 95% so I don't know why parts would have been changed out. I'll post pics of them once I get this figured out and the pistols back together.

Any help or ideas are greatly appreciated. The only thing I can think of is grinding it off a little. Not real crazy about that idea as I have basic skills only but I want the pistol to work properly.

Thanks, Steve

 

[Mercury]

I'm not sure what is locking up, are you just having difficulty opening the cylinder?
Usually the first thing to check is that the ejector rod is tight. If it loosens up a bit, it becomes difficult to open the cylinder.

 

[444 Magnum]

A few more pics.

The cylinder pin is almost too long to close properly.

The cylinder fit and spacing are good once closed.

 

[armorer951]

The basic problem is the collar on the K32 center pin is in the wrong location, so it's letting the pin stick through the extractor too far. Can you send me the measurement of the distance from the front of the center pin collar to the tip of the rear of the pin? I may have one that will work.

If the center pin in the top cylinder in your photo works properly in the problem cylinder, (K32) just give the measurement of that one. (the K38)

The other alternative would be to grind down the pin to the correct length, and then re-profile to round the tip. The key here is not to get the pin too hot when grinding.....if you have to use a grinder.

 

[444 Magnum]

The .38 cylinder is longer than the .32 and will not fit the .32 frame. I didn't take the pin out and swap them. I'll have to get a tool for that.

This is the .38 cylinder length.

This is the .32 cylinder length.

Is this the measurement you're looking for?

This is front of collar to end of extractor without the pin.

 

[armorer951]

If this is a used, recently acquired revolver, I believe someone has installed the wrong center pin. Center pins have a collar that is set at different lengths depending on the vintage and model designation. The collar in the K32 is set too far forward, like the bottom one in my photo, which lets the breech end of the pin protrude from the extractor too much. The collar on the center pin controls how much the pin protrudes or "sticks out" of the extractor.

It appears that the center pin in your gun is too long in the area in back of the collar.....like the bottom pin in my photo. Disregard the different OAL (overall length) of the two pins in the photo. That doesn't matter in terms of this illustration and your situation.

You'll need to purchase and fit the correct center pin, or remove the existing pin and shorten/re-profile the end that interfaces with the breechface cavity. The pin that is in the gun now is too long from the collar to the rear. Re-profiling the existing pin would probably be easier IMO.

Carter

 

[444 Magnum]

Thank you, Carter, for your expertise.

I think I'll remove the pin from the K38 and see if it works in the K32. If so, I'll use it as a guide to modify the K32 pin.

I've never removed these pins. What tool do I need to grip and turn the extractor rod without damaging it?

 

[glowe]

Shortening the pin may result in the front lug pin not moving far enough forward to unlock the rod. The rear cylinder gap seems large and by measurement the cylinder appears to be shorter than standard?? That would make the pin appear to be longer. Is the serial number visible on the rear of the cylinder?

 

[444 Magnum]

Both cylinders are numbered to the respective pistols, but there is definitely a difference in cylinder length from .38 being the longest to .32 being the shortest. I don't have any other post-war K frames to compare these to.
Even the extractor stars are numbered.

 

[armorer951]

Steve,

I use a padded vise or a three jaw drill chuck to remove the extractor rods.
Be sure to back up the extractor by placing some empty casings in the cylinder holes, and you'll need to determine if the rods are right or left hand threaded before proceeding.

Carter

 

[jmace57]

Following this thread with interest. I have a Model 36 that seems to exhibit the exact same behavior. I bought it really cheap in an auction a while back, because you couldn't close the cylinder.

 

[steelslaver]

Make sure the lug under barrel moves freely. If the gap between end of rod and lug body is tight when closed you can remove a bit of the end of the rod and pin. If you press the assembled cylinder ratchet end down on a hard flat surface the end of center pin should come flush or tiny bit past end of rod. When I am done I always take about a 3/16 drill bit place it against the hole in end of rod and twirl it between my fingers with a bit of pressure. This removes any tiny burrs and gives it a tiny camber.


If on the other hand the pin will not press flush to ratchet you either need to shorten that end and re round it or make internal adjustments to collar as suggested by Carter

I have 2 2x72 belt grinders, with a variety of heads and lots of belts so that is what I use.

 

[StrawHat]

One of the reasons I come here is to learn. Nearly four decades have passed since I attended the Armorer’s Academy. The center pin collar is something that is somewhere in my memory banks and until reading Carter’s post, totally forgotten! I have not needed to mess with it, ever.

Today, I relearned. That is good!

Kevin