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Login Name Post: W.C. Cain set trigger...        (Topic#269163)
40 Cal.
Posts: 333
05-10-12 01:07 PM - Post#1144572    

I recently acquired a very nice flint long rifle made some years ago by a good friend of mine - it is an Isaac Hains-styled early Pennsylvania type, and very nicely done.
But it has one feature which irks me: it is fitted with a single set trigger made by Cain which can only be used in the set mode: that is, there is no way to release the sear without snapping the set, which makes it a pain to manipulate when not actually shooting, as in adjusting a new flint, or if it is desired to drop the cock from fully cocked to the half cock notch.
Does anyone have a suggestion as to what other single set trigger could be used to replace the Cain model, or has anyone ever altered such a trigger to provide unset as well as set function?
I've studied on it for a while, and can't come up with a simple way to convert the mechanism, since the trigger is not actually connected to the sear bar, and only contacts the secondary (set) sear, but does not move it far enough to trip the lock itself.
Appreciate any input.
mhb - Mike

40 Cal.
Posts: 333
05-15-12 08:21 PM - Post#1146719    

    In response to mhb

Having run out of ideas on the Cain trigger, I scouted-around and discovered that L&R makes a single set trigger with dual function, and which is close in dimensions to the Cain, so I ordered one and will attempt to modify it so as to replace the Cain. In talking to the guy at L&R, I was told that Cain did, in fact, make single set triggers with dual function.
mhb - Mike

50 Cal.
Posts: 1261
05-17-12 04:19 PM - Post#1147355    

    In response to mhb

I do recall seeing this one. I don't know if it is what you are looking for. Off to work now....

40 Cal.
Posts: 333
05-18-12 04:40 PM - Post#1147725    

    In response to dyemaker

Thanks for the tip! That is exactly the kind of trigger I'm looking for, and I'll contact the maker for details.
The L&R trigger did not work out: I had asked for the dimensions of the plate, etc., and told the L&R guy that I wanted to replace the existing trigger without having to alter the stock, if possible, which would have required thinning the L&R plate width from 7/16" to 3/8". He said it should be doable, but on inspection, the design makes it an impossibility, so I'll have to return it.
It does look like the trigger you found may have a trigger plate which is significntly shorter than the 4 3/8" of the Cain model, but I'll have to find out by direct contact.
Thanks again!
mhb - Mike

40 Cal.
Posts: 333
05-21-12 05:11 PM - Post#1148610    

    In response to mhb

Having agonized over this for a while (and discouraged by the unsuitability of the L&R trigger as a replacement), I finally decided to 'bite the bullet' and do what I had originally thought of - converting the Cain trigger to function as a simple type, without set function.
After satisfying myself that I could do this without irrevocably altering any of the original trigger parts (so I could restore it if I decided that was better), I did the work by removing the parts related to the set function, slotting the trigger crosswise through the hump at the rear end of the trigger which served to trip the set sear, and silver soldering into the slot a much higher bar intended to contact the 'sear trip bar' and lift it into contact with the lock sear.
The entirety of Sunday morning went into the project: I had to make and solder in 3 separate bars for the trigger in order to get the maximum lift possible with the original trigger parts (it wasn't possible to measure the needed height directly).
When satisfied with the trigger mechanism conversion, I installed it back into the rifle to try: frustration. In spite of lifting the trigger sear bar as high as mechanically possible , it did not contact the lock sear sufficiently to release the lock - it appeared that in the (original) set mode, the sear trip bar had just barely contacted the lock sear at a velocity sufficient to trip the sear out of the full cock notch.
What to do next?
The logical thing - heat and bend-down the tail of the lock sear. Two attempts got that moved sufficiently that the lock could now function with the trigger pull. The weight of the trigger pull-off was really heavy.
O.K., let's take the lock apart and see what is going on there. The lock parts are properly fitted and polished, but the sear spring is very heavy (as it had to be to counteract the pressure of the trigger sear lifter bar, which was always under heavy upward spring pressure in the Cain design).
Lightened the sear spring to a more reasonable weight and re-assembled the lock, tested its function and replaced it in the rifle. Checked lock and trigger function, which was now very good, with a clean pull-off at about 3 pounds.
Declared victory, having achieved the desired ends (a useable trigger pull and the ability to function the lock without setting and snapping the set trigger).
Tomorrow, weather permitting, off to the range to test the results. I expect it will be fine, and I'd rather have a good plain trigger pull than a set trigger mechanism that won't permit the lock to be tripped in the unset mode.
mhb - Mike

40 Cal.
Posts: 333
05-22-12 05:01 PM - Post#1148896    

    In response to mhb

An entire success. Shot about 20 rounds today without a hiccup - the trigger pull is just what I hoped for, and probably will never change it back. Having decided on a 'general shooting' load (65 gr. GOEX 2f, .530" Hornady ball and .023" striped matress ticking w/Falkenberry lube), I zeroed the rifle at 50 yards by filing-down the front sight to place POI about 1" high of POA and dead on for windage. It shoots nice, tight cloverleaves.
Later I'll work on a load for 100 yards or so. I'm happy!
mhb - Mike

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