Trigger/Half-cock adjustment

[JLayne]

Newbie here . . .again. I am installing a trigger on a Chambers York rifle kit. It has a Chambers Golden Age Germanic lock and a simple trigger that pivots on a pin through the lock mortise. I got the trigger filed down until it works and the lock clicks into place in half-cock and full cock. However, once the lock bolts are installed and tightened, the hammer will still wiggle a bit (1/4 ") if you apply moderate pressure to the trigger in the half-cock setting, and it will fall with a really hard squeeze on the trigger.  Does this mean I need to keep filing more material off of the trigger bar until that is no longer the case? It's my second trigger (yes, I botched the first by taking off too much material leaving way too much free play and a feather-light pull), and I wanted to seek some advice before going at it with the file. I don't know if it matters, but the trigger exhibits a slight springiness even when the hammer is down.

Thanks in advance.
JL

[Stophel]

Most locks just don't have the much-vaunted "one position sear", so there will be a difference in how much room there is between the trigger and sear at half cock and full cock.  When you have the lock screws tightened, you should have just the smallest amount of slack between the trigger and sear at half cock.  Almost bearing on it, but not quite.  If you get it too tight, as the wood expands and contracts, you'll probably end up with the trigger not allowing the sear to go fully into the half cock notch, so you gotta have some room.  At full cock, the sear is generally not as low as it is at half cock, so there will be more of the dreaded "slop", that so many people today simply cannot stand.  With the cock down, it doesn't really matter much if the sear is on the trigger or not.

Now, the half cock is NOT A SAFETY. 
let me repeat THE HALF COCK IS NOT A SAFETY

If you pull hard on the trigger at half cock, it probably will force itself out of position (and possibly damaging the sear and half cock notch in the process).  Don't do it.   

[rich pierce]

“Much vaunted”. Style points!

A little wiggle is not a big deal.  There are complicated fixes; install a very weak flat spring the pushes the trigger blade up against the sear. Much work.

[Stophel]

I like using that phrase whenever I can!   

On the half cock, some locks are more prone to working themselves out than others.  If you look at it, you can see what it's doing, as the sear will lever down against the "hook" of the half cock, pushing it down and working it off the sear.  If it's too easy to force the sear out of the half cock notch, some file work MAY be able to help, but don't expect it to hold absolutely.  I know some military reenactor units want you to hold your gun by the trigger at half cock to prove how "safe" it is... drives me nuts.

[ron w]

generally you have to have some amount of trigger wiggle, as the sear bar has to be able to move down far enough for the sear to engage the half cock notch. what happens is that once the sear engages the half cock notch, it moves up a bit making a little space between trigger blade and sear bar. that is what lets the trigger wiggle. the only way to eliminate that, is to put a very light spring against the trigger to keep the trigger bar in contact with the sear bar all the time,.... which is fine,....as long as there is absolutely no chance of the trigger spring overtaking the sear spring.