Remove a Firing Pin Bushing, S&W 642

[edwardware]

Does anyone know the doctrinally correct method to remove the firing pin bushing from a Smith 642-2? Recall this is a hammerless, aluminum, j-frame.

I've been given an almost new 642-2 that's been the victim of a 'gunschmit' (hence the cut down hammer spring, inconsistent ignition, and carmelized grease) and cheap handloads. At some point the cheap handloads ruptured a primer and gas cut the bushing.

I would like to replace the bushing. Can I reassemble the gun without the firing pin retaining pin and let the firing pin drive it out?



ETA: Well, the firing pin will not drive the bushing out. . . I suspect an EZ-Out type tool down the barrel.

 

[Slamfire]

Does anyone know the doctrinally correct method to remove the firing pin bushing from a Smith 642-2? Recall this is a hammerless, aluminum, j-frame.

I've been given an almost new 642-2 that's been the victim of a 'gunschmit' (hence the cut down hammer spring, inconsistent ignition, and carmelized grease) and cheap handloads. At some point the cheap handloads ruptured a primer and gas cut the bushing.

I would like to replace the bushing. Can I reassemble the gun without the firing pin retaining pin and let the firing pin drive it out?

View attachment 808231

ETA: Well, the firing pin will not drive the bushing out. . . I suspect an EZ-Out type tool down the barrel.

I just flipped through my Kuhnhausen book on the S&W revolver and, maybe I missed it, but I don't see anything on replacing the firing pin bushing.

My suggestion, call S&W and get a shipping number. S&W will give you a better shipping rate than you can get on your own. If anyone can fix your M642, the factory is the safest choice.

 

[edwardware]

Kuhnhausen's a valuable reference, but he has very little to say about the post-97/MIM internals revolvers (other than derision, which I understand). This little guy is nearly a decade into the MIM era, and has more molded than machined parts.

I would replace the bushing if I could see a way to remove it, but I can't see one other than going down the bore with a cutting tool. . . I think I'll shoot it first. It's WAY less sluggish with a tablespoon of varnish mucked out.

 

[BBBBill]

First, I agree with sending it to the mother ship for their assessment. S&W will do it right if they believe that it can be done.

But if you must....
Bushings are usually staked in place with an annular staking punch. The metal surrounding the bushing is displaced to retain the bushing. You could cut it out from the front and collapse the walls inward or support the frame across the breach face on an arbor press with a clearance hole a few thousandths larger diameter than the bushing and press it out from the rear with a proper sized punch configured to get around the hump/closed backstrap of the frame. The punch would look somewhat similar to a GI front sight staking punch for a 1911 with an offset/notch to clear the spring tunnel.
Steel seems to accept re-staking more readily than aluminum without fracturing, so proceed with caution as you may get only one chance to get it right. Try very, very hard not to remove any of the frame metal around the hole.

 

[edwardware]

Hi @BBBBill, it's been a while since I've seen you. Good to see you again.

I agree with the annular staking, and it's not worth risking the frame. I'm going to shoot it and see.

This pic makes it look worse than it is, but for context:

 

[Slamfire]

Hi @BBBBill, it's been a while since I've seen you. Good to see you again.

I agree with the annular staking, and it's not worth risking the frame. I'm going to shoot it and see.

This pic makes it look worse than it is, but for context:
View attachment 808308

Looks bad, but it may be just cosmetic. If the primer flows back into the firing pin hole and ties up the pistol, if the primer flows into those erosion channels and the cylinder does not rotate, then it is a function issue and must be addressed. If it does not affect function, put in new springs, a new firing pin, and just shoot the heck out of the thing.

 

[edwardware]

Looks bad, but it may be just cosmetic.

The box of brass that did the damage came with. I think it's cosmetic.

 

[Slamfire]

The box of brass that did the damage came with. I think it's cosmetic.
View attachment 808338

Ugh!. The primer flow into the bushing face sure looks like something that could cause a function issue. You are at the stage I periodically encounter with old vehicles. Something is wrong, the correct fix is expensive and time consuming. The first thing to do is go to the automotive store and buy any bottle or spray can that has the word "Miracle" on the label. Pour it in the tank, radiator, or spray it on, and pray for a miracle.

And if God withholds his blessings, punt, or spend a lot of time and money fixing the problem.

 

[Drail]

deleted

 

[edwardware]

@Drail: I agree, it does look like a carefully made offset punch in a press could do the trick. . .

 

[Ken T]

The bushing shows evidence of annular staking in the photo.I see two problems.The alloy frame will be hard to restake and the frame has damage which has removed part of the staking.Green Loctite might hold the bushing in place.The normal way to remove such a bushing is to drive it out with a punch from the rear.

 

[Slamfire]

Does anyone know the doctrinally correct method to remove the firing pin bushing from a Smith 642-2? Recall this is a hammerless, aluminum, j-frame.

I've been given an almost new 642-2 that's been the victim of a 'gunschmit' (hence the cut down hammer spring, inconsistent ignition, and carmelized grease) and cheap handloads. At some point the cheap handloads ruptured a primer and gas cut the bushing.

I would like to replace the bushing. Can I reassemble the gun without the firing pin retaining pin and let the firing pin drive it out?

View attachment 808231

ETA: Well, the firing pin will not drive the bushing out. . . I suspect an EZ-Out type tool down the barrel.

If S&W tells you the frame has to be replaced, because of etching around the bushing, I propose a Hail Mary. I remembered that Stainless filled Devcon epoxy is used on molds. I know the stuff is incredibly hard. I don't know if it is adhesive enough to hold up to the pounding of cartridges, but, it might. Half a teaspoon's worth would be more than enough to fill the cracks/etching. You would have to clean the bushing face off with a cleaner that removes all residue, for the epoxy to stick. I do hope that it does not come down to this.

 

[edwardware]

If S&W tells you the frame has to be replaced. . . I remembered that Stainless filled Devcon epoxy is used on molds. I know the stuff is incredibly hard.

Frankly, I'm not planning to send it to S&W if it doesn't tie up from primer printing; judging from the half a box of brass I have that was fired after the failed primer, I think it still runs.

That said, I might try some steel-filled epoxy just to see how it holds up. This gun will need a 200 round shakedown before carrying anyway. Good idea!

 

[edwardware]

Happy to report that after 50 rounds of my J-frame handload (158gr LFN, +P dose of W540), the primers barely print in the bushing damage. . . the gun runs like a top.

 

[FROGO207]

I wonder just WHAT the pressure was on those brass reloads that came with the revolver anyway. Betcha I would never attempt to fire any loaded that stiff in any 38 SPL firearm. Glad it worked out OK for you and the S&W.

 

[Wireman]

I have to admit I've never seen the actual bushing, which of course is hardened steel, flame cut around the edges. How that could happen and not have the frame blow up too is a mystery. The f.p. bushing is not mentioned in KH because it is not replaceable except with factory tooling. Think about the long staking tool that must go through the barrel and the supporting block for the frame to back it up. Some years back when the 686 was first introduced, the factory recalled a few of the early ones for bushing replacement. .357 mag primers apparently did flow around the firing pin (then a real hammer mounted firing pin) and could have presented a safety problem to the shooter. New bushings were installed that were a closer fit to the f.p. Primer flow in the 642 with anything short of a bomb for ammo would be almost impossible. Also, your model has the new frame mounted firing pin that would not let any gas flow toward the rear. Keep in mind that the primer strike depth and the appearance of any marks on the case head are produced AFTER the primer has actually ignited (in its forward position). The primer backs out of the case head and slams the recoil shield, followed by the case head slamming backwards as the pressure increases in the chamber (reseating the primer).

Personally I would send it to S&W for a new bushing. I wouldn't be surprised if they did it at n/c. A damaged bushing just does not happen in the real world. I would bet that the damage you see was not made by over pressure ammo, but instead by someone hammering on the bushing using a punch placed through the barrel.

-WM

 

[Drail]

Yup, that is what we smiths call "factory repair only"