N frame push-off

[comfortsource]

Good morning,

I have a 29-3 & a 28-3 that were acquired used a few years ago. They are not cherry by any means, great shooter grade pieces. After reading up on "push-off", I decided to check all the wheel guns and found these two (which are my only N frames) to have push off.

the question is this: I live in KS and was curious if anyone has leads on S&W gunsmiths nearby? I've heard Glenn Customs out of AZ is a great asset, I'd just simply have to send these guns off. Thanks in advance!

Jared

 

[Hapworth]

1) Did you use gentle thumb pressure to check? Some folks put muscle behind it, which is incorrect, potentially damaging, and might induce the appearance of push-off where things are otherwise mechanically sound.

2) Have you made sure the strain screw is fully seated? If it's backing out, the lack of adequate mainspring pressure can cause push-off where again things are otherwise mechanically sound.

3) If you have legit push-off, the most common cause is a worn or improperly stoned angle on the trigger hook that engages the single-action notch on the hammer. Mind you, there are other possibilities, but this is the first thing to look for if true push-off is established.

If so, it's usually a pretty simple fix for those that have the proper jig and stone at which to re-establish the correct angle. I don't have personal experience with Kansas gunsmiths, but I believe our very own Protocall Design -- who knows his way around a S&W wheelie -- is in that neck of the woods and might be able to assist or advise.

 

[armorer951]

Checking the SA pull rating is always the first step in determining if you have a problem. Single action should come in around 3 pounds. Anything below 2.5 pounds is an indicator that something is amiss.

If you have the opportunity, you might also check to confirm that the rebound slide springs in both of the guns are full length, OEM springs. If the rebound springs have been cut or replaced with aftermarket springs of a lower rating, this can contribute to push off. As Hapworth has indicated, correct tension at this interface is critical with respect to proper single action function.

 

[Protocall_Design]

In my experience, with the above mentioned items being checked off, 90% or so of pushoffs are due to the trigger part of the SA sear being the wrong angle or having a slight radius on the corner. This is an easy fix, if that is the problem.

Every gunsmith has their own favorite ways of doing each type of repair. I will share my way for what it may be worth.

I use a 1/2" square x 4" or 6" long stone laying on a steel block. Holding the stone and trigger flat on the steel, with about an 80 degree angle between the top of the trigger and the stone, move the trigger along the stone to hone the rearmost face of the trigger. This gives about a 10 degree very perpendicular edge on the trigger and a sharp corner on the bottom. The actual stoning takes a minute or two, much quicker and easier than it sounds.

You need to keep the back face of the stoning exactly 90 degrees to the sides of the trigger so it engages the hammer notch all the way across. This is hard to do free hand, but very easy by holding both flat on a hard surface. You have to use a stone that's square and true, not worn.

 

[Hapworth]

Question on this subject for anyone who may know: when stoning to return the single-action trigger hook to true, how best to avoid going through the case hardening?

 

[Protocall_Design]

I have never found that to be a problem. Everyone who says that either doesn't know much about metallurgy or is grinding off way too much material, or just parroting someone else who didn't know. A small amount of stoning or polishing will not be an issue. I've been a tool & die maker for 45 years now, having worked with tool steel and heat treating most of that time, plus making precision parts with all metals.

 

[Jeff423]

This issue is addressed in the FAQ "sticky" at the top of this forum.