Super light trigger/bent sear spring?

[IdahoMatt]

I very recently picked up a Pedersoli “Kentucky” rifle from a pawn shop. It is a single (simple) trigger model. Everything outwardly looks great, clean bore, etc. The trigger pull on it borders on being too light! In all the research I did, I have only come across the opposite problem. When I took the lock off it looked fine to me( other than some roughed up screw heads), but when I compared it to a picture of a pedersoli replacement lock, I am thinking that maybe the sear spring is bent. The top picture is from VTI gun parts. The bottom is mine. Thoughts???

 

[Griz44Mag]

Judging from the picture, I would reason that the previous owner had disassembled, lightened the spring tension, probably filed the sear engagement to a shallower angle and polished it, trying to lighten the trigger, and succeeded.
A few new parts from Pedersoli and all will be as shipped from factory.

 

[IdahoMatt]

Judging from the picture, I would reason that the previous owner had disassembled, lightened the spring tension, probably filed the sear engagement to a shallower angle and polished it, trying to lighten the trigger, and succeeded.
A few new parts from Pedersoli and all will be as shipped from factory.

Thanks, that's what I figured. Looks like a new tinkering project!

 

[hawkeye2]

Take the lock apart and check for wear on the sear nose and the full cock notch. The lock has been apart before, see the buggered up screw slots, and look for a DIY trigger job, bad gunsmithing could be the problem. While the lock is apart reassemble the bridle, tumbler, sear and sear spring and check the pressure on the sear to see just how light it is. A lot of sear springs come with that curve in them from the factory and I suspect the problem may be something other than that little spring.

 

[IdahoMatt]

Take the lock apart and check for wear on the sear nose and the full cock notch. The lock has been apart before, see the buggered up screw slots, and look for a DIY trigger job, bad gunsmithing could be the problem. While the lock is apart reassemble the bridle, tumbler, sear and sear spring and check the pressure on the sear to see just how light it is. A lot of sear springs come with that curve in them from the factory and I suspect the problem may be something other than that little spring.

I have not disassembled the lock yet, waiting on a mainspring vice in the mail. When I hand actuate the sear (with the lock out of the gun), it is just as light as pulling the trigger. Barely any pressure needed.

 

[Brokennock]

Why is the screw slot in the top right screw off center so far?

 

[IdahoMatt]

Why is the screw slot in the top right screw off center so far?

I laughed out loud when I saw that screw, excellent QC. Ill be replacing that one for sure!

 

[Dphar1950]

Its possible the sear nose and tumbler notch have been modified. The spring is NOT supposed to hold the sear in the notch. It should stay in with not spring pressure. If the lock clicks nicely when the lock it cocked then its NOT the spring at fault. Try swinging the spring away from the sear and then put the lock on full cock and carefully ease up on the hammer. It should stay at full cock. If it does not you need professional help.

 

[rafterob]

You are correct in that the spring is not meant to "hold" the sear in the notch, but it is meant to guide it there. The stiffness of the spring will affect the trigger pull along with the depth, angle and polish of the full-cock notch.

 

[Dphar1950]

The increasing the trigger pull with a heavy spring is obvious. However, having a lock that will not hold full cock without the spring is EXTREMELY DANGEROUS. THAT was my point. Eventually, if worn and some Italian guns in the past had SOFT INTERNALS. Or if someone with enough knowledge to be dangerous has "lightened" the trigger pull by fooling with the sear and notch. The spring may well no longer hold the lock in full cock. AND using the spring to increase the trigger pull will also give a creepy trigger pull with no "break". Where as a properly fitted notch and sear nose can give both an adequately heavy pull and a clean break with little creep. But the person doing the fitting needs to understand how its all supposed to work. Cock the lock, in the rifle. Then give it the "mallet" or screw driver handle test. A 4-5oz rawhide mallet/dead blow or a large screwdriver handle struck on the barrel or even the lock bolt head sharply enough to jar the gun should not cause the hammer to drop in 3-4 strikes. Its easy to get a trigger pull on a sidelock to 2 pounds or less and still pass the test. IF you understand how everything works. Very heavy sear springs can be used to disguise an unsafe lock. So as long at the lock has a nice "click" as the sear falls into the notches the spring is OK. Again its not the springs job to set the trigger pull in a sidelock. Its meant to put the sear in the notch properly. To do this it needs to be a lively spring with ADEQUATE PRESSURE. Yes it will add to the trigger pull weight. But it should not be the primary weight. Its just something that is naturally added on since it must have some pressure on the sear to for the lock the function properly. But the lock should stay on full cock even if the spring is removed after the lock is set to full cock. If not its DANGEROUS.

 

[IdahoMatt]

Very good point @Dphar1950 . As soon as I get a mainspring vice in I will be taking the lock apart completely. From what I can see without disassembling it, it looks like someone may well have tinkered on that notch. The gun passes the mallet test with the spring in, but i will have to see if it does without it. I will keep posting pictures and updates! Thanks!

 

[IdahoMatt]

Here are pictures of the tumbler and sear. As a novice to these types of locks I cannot be sure, but it looks like the full cock notch has been filed down, and is much smaller than the half cock notch. The sear may also have been worked on, but I have no cross reference pictures. @hawkeye2 @Dphar1950

 

[hawkeye2]

It's difficult to tell from the photos but the nose of the sear looks short and blunt, couldn't see the notch well enough. The tumbler has provision for a fly which isn't really needed in a simple trigger gun, did you remove one? Now that you have the lock apart you can assemble the different components and see their relationship, the problem may be obvious.

 

[IdahoMatt]

Yes, I removed the fly for the picture @hawkeye2. Here's a black and white with some better contrast.

 

[hawkeye2]

A real bad angle on the full cock notch. Draw a straight line from the center of the tumbler pivot to the tip of the full cock notch for a correct cut. You might be able to correct it but it probably would need to be hardened again and it may cause trouble with the fly. I would be tempted to replace the tumbler and sear if they are avaliable and start over again.

 

[Loyalist Dave]

Um I'm pretty sure that notch should be closer to 90 degrees (red). It's marked in black and clearly more than a 90 degree angle.



LD

 

[IdahoMatt]

Thanks! I think I'll just replace it. I'm not into it for much money, so I don't mind replacing a part or two. @hawkeye2

 

[hawkeye2]

Probably the best idea, that setup is dangerous.

 

[IdahoMatt]

Thanks for the graphic @Loyalist Dave , this place is great!