Trigger Creep

[Cincinnati Slim]

Howdy All,

Got me a blue steel Pietta 1860 Army with a 5 1/2 inch barrel. It's a good shooter and with TRM nipples and #11 Remington caps perfectly reliable. Had a dovetail cut on the barrel and now can drift in various height Marble's/Williams front sights to shoot to point of aim with various loads. I've polished all the innards and the action is slick and well timed. My only complaint is the creepy trigger.

I have not touched the hammer notch or trigger sear contact area. Springs are stock. Hammer is very easy to cock but I don't get misfires. Should I try a new mainspring or trigger/bolt spring ?

I'd trade a stiffer pull for a cleaner break. The problem has gotten worse with use. Could I be using TOO MUCH LUBE ? This Ballistoll stuff is super slippery and gets everywhere. The hammer notch trigger engagement angle seems OK.
I can't force the hammer forward without pulling the trigger and the gun always cocks solid and holds. Trigger engagement is ALMOST at the max hammer travel. I can pull the hammer back maybe a 1/8th inch further back to it's contact with the backstrap and it holds cock after release.

I'm not afraid to get the files or stones out and have a go at this myself.
Should I work on the trigger or the hammer first ? I'm gonna order replacements from VTI first so if I screw-up I'm not stuck. Maybe I should try installing the replacement trigger and hammer first and see if that helps ?

Anybody who has tips to share or links to direct me to is most welcome !

Cheers,

Cincinnati Slim

 

[Plink]

I think I'd be tempted to take a look at sear/hammer engagement. That's where creep comes from. The minimum safe engagement for *most* sear/hammer setups is .020. I'd be willing to bet you have .050-.060 or so. I'm not familiar with the sear setup in that gun so I don't have any specific recommendations, but I normally reduce engagement at the sear by stoning an angle on the edge that engages the hammer ledge. This lets the ledge slip off the sear easily. Take a look at the setup and see if it would be better to reduce the ledge instead. It's usually better to work the leading edge of the sear if possible though. I think I'd try for .030 and see if that eliminates the creep. That should give a nice safety margin. Be sure to check for positive engagement as you stone, though it shouldn't be an issue since this doesn't involve changing the angle of engagement, only the amount.

Worst case scenario, you end up replacing a sear and knowing not to go so far next time! LOL

Make notes of your engagement as you go, just in case you do end up having to replace it. That way you'll know where to stop next time.

 

[Old Fuff]

The hammer has two notches on its face. The first is the half-cock notch (to position the hammer for loading) and the second is the full-cock notch (to position the hammer for firing). If you reduce the depth of the full-cock notch it is quite probable that when you pull the trigger the half-cock will catch the trigger because it is now more advanced then the full-cock. The usual result is a broken trigger, chipped half-cock notch, or both.

On this particular revolver it is best to drill a small hole just below the full-cock notch and insert a pin. Then cut the pin down to obtain exactly how much depth of engagement you want. This method will eliminate any issues with the half-cock notch.

 

[Cincinnati Slim]

Ah Ha !

Brilliant Sir !

I will be disassembling the Colt tomarrow evening and will measure the depth
of the full-cock notch. I have some small roll pins with the appropriate size drill bits to use. I like this approach since I'm not filing on surface hardened metal or messing with the engagement angles of the sear. Inserting a roll pin is adjustable and reversable. (just pull it out and try again !)

I'll try this and won't file or stone anything for now !

Thanks,

Slim

 

[Plink]

That's a slick idea, Old Fuff! I've always done BP guns the way I was taught to do cartridge guns and it's more work that way. I think I'll give your system a try next time too.

 

[Old Fuff]

It's nothing new, but be aware that the pin will only stick out about .002" to .005" at best after it's trimmed to size, so it is unlikely it can be pulled out. Therefore go careful.