I have a Pietta ‘51 navy in 36 caliber, steel frame, purchased new in January 2021 with a production date of 2020. My problem is my wedge is being deformed. Last summer the wedge had been narrowed so much that it would easily slide all the way in and touch the wedge retaining screw. I purchased a new wedge from EMF, the same place I purchased the pistol, and it has started to deformed the same way. Thinking that it may be an arbor problem I checked it with a scrap piece of pop can left over from making percussion caps. The barrel will not fit tight again the frame with a single piece put in the arbor hole. What can I do to prevent the wedge from being deformed?
Wedge question
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Captain*kirk
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The wedge has to be driven home with a mallet to accurately check the gap clearance; i.e. a compressed fit. Did you do that or simply tap it in?
LaneP
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IMHO and pending the more experienced professionals responding, the wedge is too soft and the forces of pressing bullets into the cylinder and firing the gun all act to drive the barrel assembly forward. If the wedge is of insufficient hardness, it will be prone to deform. In the 70's all the inexpensive, brass frame Navy copies I bought would eventually deform the wedge. At one point I hand made a replacement and hardened it by oil quenching. That helped dramatically but I didn't hang on to the pistol very long after for a long term assessment.
The gap clearance doesn’t change. The arbor is fully seated. Driving the wedge home just deformed the wedge.
I am not a machinist, I could not make a wedge. Could a new wedge from Pietta be hardened? Do you think that a soft wedge is the problem?
crstrode
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How hard are you "Driving the wedge home"? With Three distinct knocks?
I generally just press them in with my thumb or the heel of my palm. As long as nothing is wiggling, it seems to work just fine.
I have done both. I started doing the light press, sometimes using a light nylon hammer, usually with my thumbs. After reading about driving the wedge in is when I started having problems. It seems that driving the wedge in narrows the wedge and that is what has caused the problem. The more pressure I put on the wedge the looser it is.
hawg
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How hard are you driving it in? All you need is a single light tap after you get it thumb tight.
Ephraim Kibbey
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If the hardness of the wedge is not the problem and it is not deforming from your driving it home but rather from loading and shooting:
Where is the deformation on the wedge?
If in the center, then the sides of the slot in the arbor may not be in contact with the sides of the wedge when it is tight in the openings in the barrel allowing the the arbor to move backward when loading or firing.
If it is deformed where it enters and/or leaves the barrel, then the slot in the arbor is tight but one or both of the barrel openings is too big and is allow the wedge to batter itself against the opening.
I would compare the three slots' widths and the taper of the wedge width to see if it is in contact everywhere.
Even a slight movement at one of the three contacts could cause trouble.
Once you find the trouble spot, try correcting the wedge width so that it is a more uniform fit.
Where is the deformation on the wedge?
If in the center, then the sides of the slot in the arbor may not be in contact with the sides of the wedge when it is tight in the openings in the barrel allowing the the arbor to move backward when loading or firing.
If it is deformed where it enters and/or leaves the barrel, then the slot in the arbor is tight but one or both of the barrel openings is too big and is allow the wedge to batter itself against the opening.
I would compare the three slots' widths and the taper of the wedge width to see if it is in contact everywhere.
Even a slight movement at one of the three contacts could cause trouble.
Once you find the trouble spot, try correcting the wedge width so that it is a more uniform fit.
LaneP
Member
That's an unknown at this point. I would try all other suggestions and perhaps reserve that as a last resort option. Back in those days I had a great friend and we did all sorts of gun related stuff (nothing too complex though) from hand made wedges to hand cut screws and other small parts, with nothing more than simple hand tools and files. That was just one of numerous things we did to keep those guns running.
Captain*kirk
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In that case, remember that the wedge is designed to be the 'weak link' in the chain and fail (deform, etc) before either the barrel lug slot or the arbor slot. Using a case hardening material like Kasenit on the wedge may temporarily solve your issues, but may also impart the stresses onto the less desirable parts.
hawg
Member
What Cap said. Remove the wedge and see if there's any overlap between the two slots. If there is you're going to have to adjust the slots by filing until they're equal. You may have to make a new wedge if a stock wedge is too small after adjusting the slots. If the slots are already equal you may be using too much force driving it in.
SomebodyMakeRiderRepro
Member
I find it odd that the .36 charge deforms the wedge (in any reasonable time) given how low pressure (light) .36 is.
I've once had an unhardened pietta hammer and it went out of time under a hundred or so shots. One reason might be that they messed up the hardening. However, it is extremaly unlikely the replacement wedge would suffer from the very same issue.
This leads me to believe the issue comes not from shooting the gun but loading it. While you apply pressure to seat the ball only the wedge keeps the two assemblies from separating and thus is under severe stress. You might be using hard-alloy or oversized balls, please try hornady 375 balls and report back if the issue persists.
Cheers, Mike.
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I use Speer or Hornady .375 balls. Interesting idea about loading pressure.
Ephraim Kibbey
Member
Try a new wedge and load the cylinder off the the gun for a while.
See if the new wedge still gets beat up.
If not, it is loading pressure that is your culprit!
Jackrabbit1957
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Sounds to me like it's not bearing evenly on both sides. I would need to see a picture of the damage and the slots if possible. Is the wedge trying to fold in the middle by any chance?
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