Uberti OLs Army .44 cal. dimension help

[Tuckerp229]

Wow, now that is the Calvary to the rescue. Where do I start?

Did you do any work to the leg of the bolt that goes over the hammer cam? If not then you may have a cam problem, any way you can post a pic of the hammer cam? Unfortunately Uberti tries to deliver their parts as close to drop in as possible which doesn't leave much room for fitting for wear. Although it is unusual for a cam to wear much if it were working properly before it should work OK now. The bolt is the softer part and takes the wear. In any case your bolt should not be gouging the cylinder that is the result of a too heavy trigger bolt spring. Both Uberti and Pietta have gone to a much lighter spring I'm not sure just when they changed. You can mitigate the problem by loosening the trigger/bolt spring screw it only needs to be tight enough that the bolt still has some tension in the full up position.

1. No work to the legs. I only beveled ever so slightly the inside of the bolt head to fit the cylinder notch.
2. I will attempt a pic today.
3. I had the same premature bolt drop prior to the new bolt and as I said the hammer cam appears to me to be the shortest(protruding out from the hammer side), of all of my BP pistols.
4. I like the idea of backing the trigger /bolt spring screw out. I vaguely remember thinking when I first disassembled it that it felt loose. Maybe there was a factory reason.

One more consideration. Uberti sometimes delivers their bolts with a pretty substantial bevel all to way out to the tip of the leg. That heavy trigger/bolt spring combined with the bevel may be forcing the leg of the bolt to spring in a tad and drop the bolt early. Definetly try backing off the pressure and see if it helps.

I haven't touched the bevel yet. I was hoping for timing improvement..maybe even late crop before I started any stoning for perfect bevel. As it stands any stoing will drop the bolt faster.

On your original question of cam thickness that has little to do with anything, the diameter of the cam is the important part. Reduce the diameter or lower the tip of the bolt leg and the bolt will drop earlier. The photo shows the parts just at the point that if you rotated the hammer just a .001 of an inch the bolt will drop.

I am suspicious of the cam height. By the way that is a fantastic jig you made.

Back the bolt /trigger spring screw off a half turn and try it, keep trying a half turn at a time and see if it starts dropping at the correct point. Have you spread the leg of the bolt? That normally well correct a early bolt drop for me.

Nope I haven't spread the legs of the cam. I though it should be good from the factory.

Thanks men. I'll get to work on the picture. Perhaps your experienced eyes will pick up some glaringly obvious thing that I am missing.

 

[Tuckerp229]

Pic's. Here a re a couple pic's of the early bolt drop and chattering.

another

Hammer plus cam measurement


Hammer measurement no cam


What do you guys think?

 

[denster]

Judging from the lines on the cylinder and the length of the chatter marks your bolt is not fully retracting and is dropping before the half cock notch. The height of the cam as I mentioned before has little to do with it the .045 height is still wider than the bolt leg that rides on it. What we needed to see was the face of the cam to see if it has been altered. The top surface needs to be at 90 degrees to the flat of the cam and the edges square. I'm guessing that it is either a seriously defective factory cam or some one, not sure of what they were doing, tried some gunsmithing and muddled it up. Can't say for sure without seeing it. What I can see under the dial calipers makes me suspect that is the case.

 

[Tuckerp229]

Naturally, this is the one angle I did not photograph. Back to the drawing board. I think given my very limited photography equipment and skill, showing this next angle will be difficult. as for the early drop it is impossible to see in there however it "feels" like the drop occurs just prior to the chatter marks. I think this belief is supported by the chatter marks themselves as they otherwise inexplicably start after the clean drag marks. In other words I think the drag marks are from me turning the cylinder after letting the hammer down from half cock or the chattering would commence immediately. My guess is that the chattering apart from early bolt drop is from a non-rounded bolt head and an over tight trigger/ bolt spring.

As a side note, I just stripped my San Marco Walker. The cam on this gun is equally as short off the side face of the hammer. My other BP's have much taller cams. The face of the cam is angle cut from one side to the other whereas my Pietta's and Uberti's all have a two plane cut sometimes described as one face of a hatchet.

As a way side note, I feel pretty sassy now because I was finally able to solve a nagging cylinder binding problem with the San Marco. I could only shoot 3-8 shots before the cylinder bound up and had to be helped through the cocking cycle. Turns out it was an overly wide wedge. After removing a bit of material from its sides I can now push it in by hand and the cylinder rotates smoothly.

 

[denster]

I'm going to repeat this one more time. The height of the cam is not the problem. .045 is more than adequate. The bolt is clearing the notch when you start to cycle but is being dropped about one bolt width into the cycle that is a real early drop. The chatter marks are from the high side of the bolt the lighter drag marks are from the top surface of the bolt behind the high edge not from you rotating the cylinder by hand after you lower it from half cock, if that were the case the drag marks would be where the chatter marks are.
I can only think of two possible causes for this to this degree. One is that the bolt doesn't have enough clearance to snap over the top of the cam on the hammer return and you only have friction carrying it up a little way before it drops when you cock it. The other is that someone has tried to smooth the top edge of the cam where the bolt rides and in so doing put a bevel on it so that the bolt slips off the cam. That is why I asked for a picture of the cam looking straight down.
You can check for the first by just taking the triggerguard off and ,using a flashlight, look at the leg of the bolt with the hammer down. It should not be bent and should be laying flat against the hammer. If it is not then the bolt is not snapping over the cam. This happens a lot when someone takes some off the lip in front of the bolt trying to get more bolt engagement in the cylinder without taking a corresponding amount off the leg of the bolt.
I see your gun is probably a 2003 0r early 2004 gun as the serial number is over 5000 earlier than mine which was made in 2004. It looks like someone has done some smithing to it as I note the wedge goes all the way into the lug of the wedge.
Please don't take this wrong, as we all have to learn, but from your posts it is obvious you don't yet have a clear concept of how the internal parts interact. That makes it difficult for any of us to diagnose the problem from what you say without clear pictures.