WTF? UBERTI MODEL P LOCKS UP IN HALF COCK WHEN SHOOTING

[Wolf Killer]

Hello Lads,
I hope there are a few of you that can answer a new to me problem with a Cimarron Uberti model P in 45 Colt
For no reason that I can figure, the gun will occasionally lock up solid in half cock when shooting. It is a 4.75" barrel black powder frame model PI with around 500 rounds through it with two different loads of a Lyman 452664 250gr. bullet and a Ringers 250 gr. RNFP both over 6.5 gr. of unique at around 775 FPS know I am not touching the trigger when I cock the gun for a quick reload, seems to happen after three or four rounds are fired.

What happens as far as I know, is that the bolt is popping up during a recock and the trigger stays forward so there is a lot of manipulation going on to unfreeze the gun without damaging the cylinder slots.
All the screws are tight and the base pin in solidly in place.

I am at wits end, and I had it happen twice on Friday on a new Sheriffs model I can't say it's ammo, as it is basically a standard bullet and speed. But I am stumped and need to figure this out as now I am getting nervous about every pull of the trigger. I was not able to replicate it by working the gun as fast as I could with a cylinder full of dummy rounds over 100 times at all angles.

Thanks Lads.

DB

[Abilene]

If the bolt pops up early, I don't see how that would lock up the cylinder, since the bolt head would not be able to pop into a cylinder notch until you get to full cock.  To rule out ammo problems, have you inspected the fired ammo (when it malfunctios) to be sure there are no scrape marks on either the primer or the bottom of the rim?

[August]

In all likelihood, you're pulling the hammer back further than necessary when trying to engage the half-cock notch.

This happens occasionally when I get in a hurry with my Short stroked Pietta's. 

When it happens, just bring the hammer all the way back, lower it, and start again -- assuming there are no live rounds in the gun.

[Advertising]

[Wolf Killer]

Thanks for the swift replies, but please read the problem again

The ammo is fine, and I am not trying to reload the gun by going to half cock.
This happens in the midst of shooting, you move to recock the gun for the next shot, and the hammer suddenly won't go back to full, the gun is stuck in the half cock hammer position and the cylinder will not turn by either hand or by cocking. The hammer can be lowered, but it can go no further than half cock as the bolt is now stuck in the up position.

This doesn't happen all the time, but it is enough to cause concern, as you would be out of the match at this point or dead if there was a self defense need.

I have had to pull the pin and carefully roll the cylinder out of the gun to get it untied.

DB

[Abilene]

I have to assume it is not the cylinder pin moving forward, as you would probably have noticed and it would still cause a problem with dummy rounds.  I suggest taking the gun apart and inspecting the bolt for a cracked leg and check the hammer cam for a bur.

Pettifogger will probably see this and may have a better idea.

[Coffinmaker]

The bolt leg is not "re-setting" when the hammer falls.  Either the cam on the hammer is peened toward the front (bolt leg side) or the
bolt leg is too wide or the hammer cam is slightly miss-located on the hammer.  If the gun is stock, there is also the possibility the cylinder pin is pushed in past the first detent, interfering with the hammer fall.

Coffinmaker

PS:  I'm not Pettifogger nor did I spend the night in a Holliday Inn Express (That I'll admit)

PSS:  Most of us here in CAS City aren't really enamored with the acronym "WTF"

[45 Dragoon]

Yap, that Coffinmaker got it ^^^

Mike
www.goonsgunworks.com

[Wolf Killer]

The bolt leg is not "re-setting" when the hammer falls.  Either the cam on the hammer is peened toward the front (bolt leg side) or the
bolt leg is too wide or the hammer cam is slightly miss-located on the hammer.  If the gun is stock, there is also the possibility the cylinder pin is pushed in past the first detent, interfering with the hammer fall.

Coffinmaker

Hello,
if this is true, it would happen when not shooting, and would happen all the time.
This malady occurs only when shooting, and at about 2 to 3 times in 50 rounds. .
Like I said, during shooting, I go to recock the pistol for the next shot, and the pistol will not go to full cock it is now stuck in going no further than half cock I can lower the hammer, but the trigger doe not reset when lowered. The bolt is up in the notch keeping the cylinder locked in place.
It boggles the mind.
DB

DB

[45 Dragoon]

Not so. The hammer's forward movement is being restricted by the cartridge when firing. With empty cyl, it can go fully forward. It may not be enough for you to see but you should be able to hear it. The two "clicks" you hear when letting the hammer down is 1- the hand slipping over the next ratchet tooth and 2- the bolt arm snapping over the cam to reset (in that order).

Not too mind boggling (you just gotta know what yer lookin for! Lol).

Mike
www.goonsgunworks.com

[45 Dragoon]

Since you're reloading, it may be some case heads out of spec., more likely not quite fully seated primers. These could be stopping the hammer just short of full travel to allow bolt reset. Also, could be a firing pin a wee bit long.
I'd put money on the primers. Do you clean the pockets?

Mike
www.goonsgunworks.com

[45 Dragoon]

Well, he asked What's The Failure!?

 Recon we got it for him, he hasn't responded. Hmmmm

Mike
www.goonsgunworks.com

[Wolf Killer]

Well, he asked What's The Failure!?

 Recon we got it for him, he hasn't responded. Hmmmm

Gents, No the problem is not solved with high primers.
I haven't responded, as my mother board in my ancient Mac went to Boot Hill. I am now just getting all my old data reloaded.

I Just can not get across to you the problem. Like I said, it doesn't happen all the time but enough to put you out of a match or get you killed.
So here we go again. I shoot Bang, Bang Bang, then you cannot cock the pistol into or past the half cock position as the bolt will not drop if you try to cock further. It is the bolt, as I now have small nicks in my cylinder notches. It is at this point you can lower the hammer by pulling the trigger a short distance, but trigger does not go into the full rear position that a hammer at rest has, it stays centered. in the frame.
It appears, the the revolvers innards are stuck in the first click or so called safe position, at this point the trigger moves forward and the bolt is still up.
If you try to go to full cock, the bolt will drag across the cylinder. No matter how you manipulate the hammer, the trigger drop back from the first click safety position and drop the bolt to go to half cock then to full. The only way out of this condition is to pull the cylinder, and gently pull the hammer till it rolls out.
At this time, the gun will go back into the regular use of hammer back to full and drop with the trigger.

This is some kind of recoil induced situation between the bolt and the trigger, but exactly what is unknown.

I don't know if I have a bad trigger, bolt leg or hammer cam, but Ike I said, I can not duplicate it by dry fire with snap caps.

I am beginning to think it is a trigger bolt spring or an out of dimension bolt or trigger screw, since it is recoil induced.

Thanks,
DB

[45 Dragoon]

Well, it's still the same problem which is the bolt not resetting. The bolt arm will need to be clearanced  or it could be  .   .   .   .   .   .the bolt arm is playing with the trigger every now and then. If you take the grip and trigger guard off and lay it action side up (barrel pointed away from you), you can cycle the action and watch everything happen. The bolt arm lays right by the trigger and sometimes, depending on how much the arm is sprung over it will interfere with it.
 You can take some off the thickness of the trigger and then round the corner on the sear to make sure it won't snag anything.

Mike
www.goonsgunworks.com
Follow me on Instagram

[llanerosolitario]

I would check gap between forcing cone and cylinder if  the problem happens only when firing.

It happens often that so many revolvers come with too tight forcing cones from the factory.

[RRio]

Well, it's still the same problem which is the bolt not resetting. The bolt arm will need to be clearanced  or it could be  .   .   .   .   .   .the bolt arm is playing with the trigger every now and then.

Mike
www.goonsgunworks.com
Follow me on Instagram

As a SAA Specialist since 1978, I concur 100% with 45 Dragoon. Have an action job done by a QUALIFIED smithy that has experience with SAAs. (There are too many "gun repairmen" that say they can work on a SAA, in reality do not have a clue.)  

[45 Dragoon]

Wow, thank you RRio!  It's amazing how much thought and work can go into 4 parts and 4 springs!!


Mike
www.goonsgunworks.com
Follow me on Instagram @ goonsgunworks