Armi San Marcos Walker Issues

[Kenton38]

Good evening gentlemen!

Long story short I come before you hat in hand, with a puzzle I am trying to solve. My understanding of C&B revolvers is entirely theoretical, with very little practical experience.

I have recently come into possession of an old Armi San Marcos .44 Walker replica. I immediately noticed a few issues with it. First of all, the barrel wedge was not fitted correctly. Secondly, I observed that the hammer sight notch had apparently never actually been cut out at the factory. The barest hint of a notch was visible, but no sight picture at all could be seen when cocked.

I took a vise and a file and fixed both those issues today and am pleased with results. However, during test firing I discovered an even more concerning series of issues.

1. I could not reliably ignite percussion caps. I loaded all six chambers with caps three different times, and failed to ignite two or three of the six each time.
2. When I was able to set off a cap, the force of ignition bounced the hammer back so far that it turned the cylinder out of alignment completely. This happened first with a 50g charge of triple F Goex, which I though concerning but not immediately alarming. Then it happened again with an empty chamber and only a percussion cap!

The hand appears burred up and soft. I also observe a good bit of marring and tearing to the cylinder at the dog holes.

My question is, is this something that I can fix or get fixed? Or is it a lost cause? I’ll try to take some pictures and attach them in a reply.

Thanks!

 

[noelf2]

Sounds like a weak hammer/mainspring is the main problem. Armi San Marco isn't made anymore but you may be able to find an ASM mainspring, or you could probably fit a Uberti mainspring in it's place without much, if any, trouble. Try www.vtigunparts.com.

 

[Malachi Leviticus Blue]

Besides the likely weak spring, If the Walker has been dry fired quite a bit then the nipples will be mashed and ignition will be iffy.
I've "cleaned up" some very damaged nipples and made them fire reliably.

 

[TheOutlawKid]

Without seeing it is hard to tell...may not be the main spring at all as usually they are overbuilt as stock. What i have seen with most walkers/dragoons customers send me is the barel wedge fitment and it leaves a large cylinder gap which when the hammer hits the cap it causes the cylinder to be pushed away toward the barrel forcing cone. On a properly fitted gun theres only .002-.005 cylinder gap so once the hammer hits the cap/nipple it pushes the cylinder only that .002-.005 inches and stops because.the cylinder has hit the barrel forcing cone. Basically you have too much "play" or "slop". Hmm i can tune it for you and i dont charge much..atleast ive been told i dont. Ive done other walkers and dragoons with some positive feedback in the forum that you could search. But thats what i think it is without seeing it. Them guns are notorious for having so much play in the barrel wedge area

 

[45 Dragoon]

Yes, the Kid could be right. It could also be because of its short arbor (all open top revolvers have short arbors save for Pietta's of the last 10 or so yrs.). If you can drive the wedge in far enough to lock up the cyl., do that and back it out just enough to free up the cyl. Then check for ignition problems.
Your cyl movement when the hammer drops is more likely the bolt head not fitting the locking notches/ engaging the notches deep enough/ weak or cracked bolt spring or any combination of these. You say the notches are messed up, there may be metal pushed into the notch impeding lockup. There's a lot that can go wrong with these "simple machines".

Mike

 

[noelf2]

I've never seen excessive hammer bounce back on recoil as anything but a weak/poorly adjusted or modified mainspring, or nipples that have been bored out too much. The latter shouldn't stop caps from popping though. Mainspring would explain both issues. Take off those grips and see what's going on before you commit to sending it off to someone. Easy to check yourself.

 

[Kenton38]

Update!

I’m going to try and attach some pictures here. The main spring appears to be just like what a Walker main spring should be. I don’t see any way to tighten or change the weight. Perhaps a brand new one from Uberti would be in order?

The nipples appear to be pretty crudely done. I ordered some slixshots to replace them with and a nipple wrench.

The hammer appears to be set at a slight angle, and comes in contact with the nipple at an angle as well. Could this possibly cause some of the cap issues?

 

[Kenton38]

More pictures.

 

[Jackrabbit1957]

My Walker has never had issues with caps following the hammer, that is also the first Walker cylinder I've seen with 6 safety pins. I did re tap the holes in the cylinder and installed T/C hot shot nipples in mine. You may also be looking at adding a shim to one side of the hammer to get it back on center although it's hard to see if there's enough room to do so.

 

[Malachi Leviticus Blue]

I don't have as much experience repairing or tuning revolvers as some of you guys do, but I've handled and fired hundreds of C&B revolvers (including Walkers, and other open tops)
Do you guys really think that the wedge fit or short arbor is the likely cause of the hammer blowback? Especially with only a percussion cap and no powder?
I like to learn as much as I can from others misfortunes and mistakes as I can so hopefully I can avoid having them myself.

 

[Jackrabbit1957]

I don't believe the short Arbor is the problem. Most likely its the holes in the nipples are too large combined with a huge barrel to cylinder gap. If it's not corrected it will probably break the main spring and possibly damage internal parts as well. At the very least it will stretch the frame. My ASM Walker had a habit of blowing the nipples out of the back of the cylinder. That was the reason it was fitted with hot shot nipples.

 

[Jackrabbit1957]

I just re read the original post, I believe the bolt is dropping late as well, as in right on the edge of the cylinder cuts if this is what's happening it is causing the cylinder stop cuts to be peened, displacing metal into to the cuts. Sounds like it needs a lot of work to make it right.

 

[Kenton38]

I will do a test fire once I have the new nipples installed. If that doesn’t remedy the issue somewhat, I’ll order a new Uberti main spring and see what happens.

The wedge that came with the firearm was far too large and misshapen. I tried hammering it through all the way, and only succeeded in wedging the barrel so tightly against the cylinder that it would not rotate at all. After filing enough material off one side of the wedge to actually make it fit properly, I found after one shot it shook very loose. The spring catch holds it in place, but it is not tight.

Inserting the wedge upside down made a snug fit, but does not decrease the cylinder gap.

The primary thing that concerns me is how just a cap alone was able to push the hammer back far enough to partially cycle the action!

 

[noelf2]

I don't think a cap alone could even partially cycle the cylinder. Is the cylinder properly locked up while the hammer is falling? It shouldn't rotate while the hammer is dropping.

 

[Kenton38]

What seems to be happening is that the force of the percussion cap is sending the hammer back far enough to half cycle the action. After the cap went off, the hammer was resting right on the edge of the safety notch in between chambers. This happened both with a loaded chamber I discharged, and with a percussion cap alone.

 

[Jackrabbit1957]

If you're able to lock the cylinder with the wedge the arbor is definitely short. How much effort is needed to cock the hammer? All of my C&B revolvers take about 4 pounds of pull to move the hammer from the down position. A simple small fish scale can be used to test this. I would check to see if the hammer feels lose when you first start to pull it back, in other words how much effort does it take to start the hammer moving.

 

[45 Dragoon]

What seems to be happening is that the force of the percussion cap is sending the hammer back far enough to half cycle the action. After the cap went off, the hammer was resting right on the edge of the safety notch in between chambers. This happened both with a loaded chamber I discharged, and with a percussion cap alone.

Classic "bolt not engaging the locking notch" problem (it isn't forcing the hammer back, the cyl is just rotating that much cause it can). Ill fit and/or not enough bolt spring tension. Also the hammer or hammer slot or hammer screw hole or any combination of these are misaligned (noticed from the pic.). Doesn't mean you can't use it, just means you need to address some issues. If the wedge isn't closing down the bbl/cyl clearance, it probably means the back of the wedge slot in arbor is in line with the wedge slot in the barrel (the slot in the arbor needs to end further back than the slot in the barrel or, you removed too much wedge material).

I will do a test fire once I have the new nipples installed. If that doesn’t remedy the issue somewhat, I’ll order a new Uberti main spring and see what happens.

The wedge that came with the firearm was far too large and misshapen. I tried hammering it through all the way, and only succeeded in wedging the barrel so tightly against the cylinder that it would not rotate at all. After filing enough material off one side of the wedge to actually make it fit properly, I found after one shot it shook very loose. The spring catch holds it in place, but it is not tight.

Inserting the wedge upside down made a snug fit, but does not decrease the cylinder gap.

The primary thing that concerns me is how just a cap alone was able to push the hammer back far enough to partially cycle the action!

The fact that the cyl locked up by driving the wedge in is proof of a short arbor ( mentioned it in my previous post). The wedge spring is there only to keep you from pulling the wedge out fully . . . and then losing it . . . The friction from "driving the wedge in" is what keeps the wedge "in place".

Mike

 

[Kenton38]

So I have a laundry list of issues here it seems, hmm... The Walker was free, maybe it’s just time to switch to a new Cimarron Navy!

So just to condense, seems I have;
1. A short arbor
2. A miss fitted wedge
3. Weak mainspring (hammer weight is definitely less than 4 pounds. I’d say more like 2 just by feel.)
4. Not enough bolt tension
5. Misaligned hammer

I’ll take some more/better photos tonight and upload them, to see if anyone notices anything else.

Thanks very much for the help! I think I’ve learned that this is beyond my ability to tackle currently without truly buggering something beyond fixing. We will see!

 

[45 Dragoon]

The new Navy will add to the fun (it will have a short arbor as well). Being that it's an import through Cimarron, it'll probably be a looker!!

As far as your list, the short arbor is the most common "fault ” with the open top platform since the " replica " industry started. Only Pietta has taken it seriously and corrected that particular problem (about the last 10 yrs or so). Cimarron's open tops are Uberti I think. Don't let that stop you though, it's an easy enough fix. They all have there problems.
Not sure a 2lb hammer draw would cause a cyl to move!! Lol but, much lighter than 4 lbs and you'll have failure to fire probs galore!! Bolt tension is easy with a new /aftermarket spring. The main thing here is the fit and depth engagement of the bolt head. So, you're in the woods but you can get out of the woods fairly easy.



Mike

 

[Jackrabbit1957]

You could send to me, betcha I can fix it. P m me if interested.

 

[Bubba32]

I would lean towards getting it sorted before shooting again, and then drop the charge back until all is known to be well with it.