I have a Model 66 no dash. It misfired when I bought it and had a light trigger. I ordered a Wolf factory mainspring and installed it. The new one is twice as thick as the old one. When I went to put the side plate back on it won't seat. There is a high spot right in the middle about where the main post is that it rocks on like it's not engaging. . Also is there a trick to installing the hammer block so that it fits into the side plate groove and stays there. I didn't touch anything but the mainspring. I had the plate off once before and didn't have any problem putting it back on.

Block should be positioned all the way up on the pin in the rebound. Then, carefully position the slot in the sideplate over the block, and lay the plate down over the block and into position. Use hand pressure to seat the sideplate. Remember, don't try to force it on, and be careful not to disturb the position of the hammer block as you put the plate into position.

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Ret. LE, FA Instr, S&W Armorer

What ARMORER 951 said, with added. I've found sometimes that when you open one up and if you work the action any with sideplate off, the hammer, trigger and assorted parts want to ride up off the frame. Take your thumb and make sure that you push down on the hammer, trigger, rebound slide and that the main spring is not sticking out either side of the grip frame but is flush on both sides of frame.Be sure the hooks of the main spring are properly positioned on the hammer. After I position the hammer block, I take the sideplate and position the top over it,at a downward angle and get it in the slot, slowly lower the rest of the side plate while I move it upward into position. Gently lower it so as not to disturb the block and place the sideplate on the frame. Be sure to have the cylinder in and as you gently place pressure on the sideplate with a palm or thumb, you may work the hammer a little to help the block settle in the side plate groove. That always helps me. Once I know the side[plate is properly seated but not all the way I will give it a smart slap with the palm of my hand, never with anything else. BE very sure the sideplate is seated properly before doing this because if it isn't you will burr it and that isn't good. Replace screws in side plate and test function.
Hopefully that will help. As with kids it sometimes is a trial and error situation. Good luck.

Also remember you can't just sit the plate down on place. With the little "tab" up at the top, it must be slid in under the frame opening.

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H Richard
SWCA1967 SWHF244

If you have not already done so, allow me to suggest that your try it without the hammer block and deal with any fitting issues you discover. This extra thick spring sounds suspicious.

If the revolver goes together easily without the hammer block, remember to position the hammer block as far up as it will go on the retaining nub before installing the side plate. As first mentioned by Mr. armorer951

One more suggestion: Place the sideplate in the freezer section of your refrigerator and leave for at least 3 hours or overnight. The plate will 'shrink' just enough to drop into place.

Bill Tolle

Second Amendment to the United States Constitution:

A well regulated Militia, being necessary to the security of a
free State, the right of the people to keep and bear Arms,
shall not be infringed.

Of course if there is any humidity in your house at all, it will condense on the inside (and outside) of the side plate and introduce water where you probably don't want it.

Did you just make this up ? For the life of me I can't imagine such advice. The side plate is machined to be removed and reinstalled for the life of the gun. It's a finess move that takes some practice. Can you imagine if freezing were to shrink the plate as you have suggested then wouldn't it affect the internal fit of the hammer and trigger bosses, hammer block, cylinder stop pin hole, rebound spring pin hole, etc. etc and as Scott accurately points out lots of condensate inside the gun.

Careful what you read here folks

Did you get it on?

Could that new mainspring be moving the hammer stud out of line with the sideplate pivot hole? Did you tighten the strain screw before trying to put the sideplate on?

BTW - the freezer tricks works on many - many items that are hard to fit. You are talking about a change in dimensions that can hardly be measured, so everything will fit just fine. The principle is the same as loosening up nuts and bolts. Heat the nut and it expands more than the bolt and makes it easier to remove.

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Gary
SWCA 2515

I recently had my side plate off my M36 to swap a mainspring and was wondering if there is a way to tell if the hammer block is still good and didn't come out of position while putting the side plate back on. Trigger seems good but I would feel better if I could make sure without pulling it off again. I think I was careful and pretty sure it was all the way up like you just mentioned.

If the side plate went back on, then the hammer block is in the correct position.

I have to agree with Mr. CelticSire.

At least with all of my J-frames, you can only get the side plate in place with the hammer block positioned correctly.

If you got it back together without using a sledgehammer then No Worries!

The few tenths (of a thousandth of an inch) a sideplate will shrink when frozen will hardly affect the location of the various holes/bosses on the sideplate. The tolerances at these locations are far more generous than that. The shrink may be just enough to get an otherwise stubborn plate into position, however.

As for condensation, it would be miniscule and simply evaporate, anyway.

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SWHF #448

Thanks. I actually was more worried about putting the main spring back together and having it fly off about a hundred miles an hour in my garage. Hope to never have to do that again.

My pleasure, sir!

I hear that and I feel your pain!

It is not just S&W revolvers that launch parts. Small fasteners on high end bicycle components are a close second.

I guess we don't even need the OP's reply to keep this discussion alive for days!

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Gary
SWCA 2515