Double Set trigger and no halfcock?

[Harrympope]

My new to me flint with Siler lock won't go to half lock unless I set the trigger.the set trigger kicker  is pushing up against the lock sear ?so it won't engage.how do I fix this?

[Huntschool]

Is the trigger double set double throw or just single.....

There are double set triggers that do not work off the front trigger unless set....

Just sayin

[Bob Roller]

If it's a trigger that  MUST be set to work at all I would say the mainspring that
drives the rear trigger is too strong.Another possibility is the trigger being set
too close to the sear.Old style caplocks with this type of trigger are common
and few old American caplocks had a half cock.Try to squeeze the rear trigger and
cock the lock and see just how much the trigger is engaged against the sear.
I am assuming these locks have a half cocked sear position that is lower that
the full cock position.

Bob Roller

[Scota4570]

Some stet triggers have a screw that limits how far the back trigger is pushed by the spring.  Once in motion the rear trigger pivots under the momentum from the spring.  It does not need to be under spring power for very long. Look for such a set screw that stop the spring that powers the rear trigger and adjust  if it is present. 

[Mark Elliott]

I build slim rifles that have the triggers close to the lock which presents me with this problem a lot of the time.   I find the easiest and best solution is to install a screw behind the rear trigger as in the diagram above in order to adjust the spring/rear trigger such that there is just the right amount of clearance for the sear to go into half cock.   I think the real problem is the lock design such that the sear bar moves down more to go into half cock, than to go into full cock.  Ideally,  the sear bar would move little as you rotate the lock through half and full cock. 

[P.W.Berkuta]

Some stet triggers have a screw that limits how far the back trigger is pushed by the spring.  Once in motion the rear trigger pivots under the momentum from the spring.  It does not need to be under spring power for very long. Look for such a set screw that stop the spring that powers the rear trigger and adjust  if it is present. 

To this I would recommend that you apply Loctite to the screw once you have it adjusted correctly. I've had this screw back out slightly and the trigger assembly reverted back to the original problematic condition .

[Harrympope]

Thanks all I'll pull it apart again and look at the geometry. for sure the set has mucho tension.
 And yes double set trigger like the picture in the posts above.

[bgf]

I wish I could count the number of rifles I've seen built this way, usually with the trigger plate inlet too deep so that the trigger bar pushes against the sear when unset.  Almost always the builder insists that it works correctly!

Assuming it's not fixable with the screw adjustment, if the plate is set too deep, the fix may be as easy as shimming it a bit so that the bar doesn't ride on the sear.  If not, you might have to take material off the trigger bar or (last resort) bend the sear up a bit.

I don't like to leave setups like this, because it is possible for the cock to slip if you try to pull it back to half cock without setting the trigger.

Just my 2¢.