Trigger Pull With New Lock

[Jim Kibler]

A short video showing the trigger pull of our new Round-Faced English lock fit in our Colonial kit.  This lock is standard production.  No extra work done on it. 

[Justin Urbantas]

Impressive

[Jim Kibler]

There are several measures for the quality of a lock.  One is certainly the pull required to trip the sear.  Related to this is the distance the sear must travel in order for the lock to fire.  You hear a good bit about the speed of a lock, but this is something not discussed a lot.  Traditional production locks vary a great deal in this regard.  There will be wide variations even within the same lock from the same manufacturer.  This is of course due to questionable design,  castings with large variations being used as well as variations in assembly.  I've tested some traditional production locks with decent pull requirements and then tested others which were beyond the scale of my gage!  And these were all the same type of lock!  I could show these, but I'll try to just focus on the product we make.

The consistency of machined parts and care in assembly associated with our locks makes the pull requirements small and repeatable.  In addition these production methods make the required pull distance to be quite small and consistent.  We even take great care to control the sear spring size and pre-load.  These springs are CNC machined and then heat treated in such a way as to control the dimensions.  With quick measurements, I've found the sear spring to contribut around 1/3 to 1/2 of the required force to trip the sear.  So careful control of this is important.

All of this is just one aspect of a quality lock.

All the best,
Jim

[Jim Kibler]

A final note.  The distance from the trigger pivot to the sear contact is about 1/2”.  I prefer this as it helps to mitigate trigger creep.  With a shorter distance the pull would be significantly less, but pull distance would be more.  I hear of people using distances in the range of 1/4” and I think this is to compensate for less than ideal locks.  In this case pull distance can be a real issue.

[Stophel]

I always set my trigger pins about 1/2" from the sear... even though "everyone" tells me it needs to be a quarter inch (most old guns I have been privy to handle have AT LEAST a half inch spacing).  Years ago, I did one once at 3/8".  Oh, the pull was light, but it took about 30 seconds from the time I started pulling the trigger until it finally let off.   I've never attempted to do another one with such a short trigger/sear spacing.  There are other factors MUCH more important to pull weight, like the sear/tumbler notch angle and the weight of the sear spring.  Get these right first, and you don't have to make guns with such crazy long trigger pulls.

[D. Taylor Sapergia]

My experience is the same, Herr Stophel.  I prefer a trigger that is not only light but has no creep, and breaks like a glass microscope slide.

[smart dog]

Hi,
I also prefer a trigger with no rattle even when the lock is at rest.  Jim, I am glad you are doing these short clips.  Lock speed is just one parameter in a good lock but many fixate on it. My ultimate test and parameter is that the lock always flashes the pan even with fouling and a dull, worn flint. I also like a light pull and no creep, however, I know several top tier target shooters that do want some creep in the trigger pull.  They prefer to feel some movement in the trigger when shooting off hand. For them, a trigger without any creep is like a set trigger, which they dislike. I understand that preference having spent years competing in modern biathlon (skiing and shooting) with a rifle that had a 2-stage trigger.   

dave

[Scota4570]

Looks great!

It also makes a huge difference if the cock is not being cammed back by the sear.  Making the sear nose to have near 100# engagement in the notch  is huge to longevity.  Nice to see someone get it right. 

I have seen new locks with a knife edge sears that cam the cock back, this is very bad IMHO.