Crane screw question

[Point 357]

This might be more appropriate in the gunsmith section...

After I installed new stocks on my 66-1 I noticed that the crane release/retention screw was loose. Naturally, as a mechanic my first instinct was to tighten it. After doing so it was waaay too hard to swing the cylinder out. I have not yet fired this gun and I'm afraid it will rattle out after a trip to the range. Would I be foolish to shave the screw down just enough so that it will snug down? The very end ~3/64ths of the screw has no threads.

 

[shawn mccarver]

That is a fitted screw, and it sounds as if someone replaced it without properly fitting it. There is a specific procedure to fit that screw. Unless you are familiar with that procedure, a gunsmith trained as an S&W armorer should do the job. Naturally, if you learn the procedure, and are good at such things, it is not "rocket science," so you could probably do it yourself if you have the proper tools, calipers and abilities.

 

[TAROMAN]

What Shawn said.
And, sometimes a previous owner exchanged the two button head screws. The factory fitted one might actually be there in the middle spot.

 

[Point 357]

What Shawn said.
And, sometimes a previous owner exchanged the two button head screws. The factory fitted one might actually be there in the middle spot.

I thought of that, so I pulled the middle screw. Identical in dimensions. Could the trigger tension spring screw have been installed in the wrong place?

 

[dfariswheel]

I thought of that, so I pulled the middle screw. Identical in dimensions. Could the trigger tension spring screw have been installed in the wrong place?

No. The mainspring tension screw is the only screw of that size on a S&W.

Try the other screw in the yoke retention hole. They are the same type screw but one is fitted and it is often a subtle difference that may not be obvious.

Be careful, if you put the wrong screw or a non-fitted screw in the yoke retention hole and open the cylinder, the joke shaft can be chewed up.
If you've already opened the cylinder and felt resistance, look at the slot on the rear of the yoke shaft for burring or damage to the slot.

 

[BSA1]

I have found that sometimes a drop of oil on the shaft of yoke will let it open and close smoothly. I keep mine well oiled.

 

[H Richard]

Was this a used gun? Is there a possibility the screw head was buggered up and replaced by the previous owner? Sounds like the screw needs to be fitted. It is not difficult to fit a screw provided you have files & stones and work slow. Remove about .001" from the end of the screw and reinstall. If it works properly then just dress it with the stone for smooth operation, if not remove another .001" etc. until it works properly. Do not remove anything from the sides of the end of the screw unless it does not fit smoothly into the notch on the crane, then using only the stone, remove just enough for it to smoothly open and close with just a touch of resistance. If you remove too much the crane will not fit tightly and it can increase head space.

 

[Point 357]

Was this a used gun? Is there a possibility the screw head was buggered up and replaced by the previous owner? Sounds like the screw needs to be fitted. It is not difficult to fit a screw provided you have files & stones and work slow. Remove about .001" from the end of the screw and reinstall. If it works properly then just dress it with the stone for smooth operation, if not remove another .001" etc. until it works properly. Do not remove anything from the sides of the end of the screw unless it does not fit smoothly into the notch on the crane, then using only the stone, remove just enough for it to smoothly open and close with just a touch of resistance. If you remove too much the crane will not fit tightly and it can increase head space.

Thank you for this. I had the gun (model 66-1 2.5") at the range today for a first fire and it did very well. I have it taken apart for a cleaning right now, and it looks like it has not been taken apart, ever. It is a used firearm purchased from a retired Pennsylvania LEO. I do see some slight gouging on the yoke swivel groove. It is minor though.

I wish I could figure out how to post pictures.