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Special Interests - Groups & Societies => Spencer Shooting Society => Topic started by: Curtis264 on February 28, 2021, 02:09:04 PM

Title: Trigger
Post by: Curtis264 on February 28, 2021, 02:09:04 PM
My Spencer's trigger pull is around 12 - 14 pounds, so I took is apart and removed some material off the spring and reduced the trigger pull down to 7 1/2 pounds, I would like to get it down to  5 - 6 pounds, will take it apart again today and do some more grinding. Even now it is so much better than it was
Title: Re: Trigger
Post by: El Supremo on February 28, 2021, 02:54:22 PM
I have been warned that issue Spencers do not have tumbler flys to prevent sear to half cock notch damage from light pulls. They were designed so angles work against themselves with a "martial pull weight".
Watch out.  Below 5# or so can cause it.
El Supremo/Kevin Tinny
Title: Re: Trigger
Post by: bear tooth billy on March 01, 2021, 08:47:27 AM
Are you checking to see if it will still set off primers.  I lowered
mine and at about 6-7 lbs. it would not set off large rifle primers.
I switched to Federal large pistol and it works, but you may want
to try before going lighter, if you haven't

Title: Re: Trigger
Post by: El Supremo on March 01, 2021, 10:47:59 AM
Hello, again:

Spencer mainsprings present a wide range of tempers.  I have tested upwards of thirty for trigger pull weight and hammer cocking effort in a single Spencer lock and found a 4# pull weight range and clearly differing cocking efforts. 

Almost all center fire 56-50 cases are designed for large RIFLE primers because it was a rifle ctg. Large PISTOL primers are the same diameter and will fit, but seat .003" lower and can cause ignition issues, especially with a weak spring.

CCIBr2 large rifle primers are widely reported and in my tests, found to be ignition problems.  Win Large RIFLE primers have been the best igniting. 

Rather than more spring grinding that leads to lighter hammer fall momentum, there is a quick test alternative. 

Cut a piece of flat shim from a soda can that is a 1/8" x 1/4" rectangle. Put it beween the mainspring screw and sear leaf.  This lifts the spring arm slightly. 
If that helps, test different thicknesses. 

El Supremo/Kevin Tinny
Title: Re: Trigger
Post by: shilohdiver on March 01, 2021, 07:50:33 PM
can you show a diagram where exactly the shim is placed
Title: Re: Trigger
Post by: El Supremo on March 01, 2021, 09:06:50 PM

Am unable to attach diagram for now.
Hopefully this is not one of those "then you just gotta" steps that is the tough aspect. 
If you know how to remove the spring, locating the spot should be easy.
Not sure how to be more descriptive. If anyone here can draw one and attach it, thanks.

Just compress spring slightly with a proper mainspring vise so the sear leaf is barely moved away from the screw head and slip the shim between the screw head and leaf. 
Removing spring vise compression will force leaf to press on and hold shim in place. 
Ideally the shim should not project past screw head so inletting is not contacted. 
Fingers crossed,
El Supremo/Kevin Tinny

Title: Re: Trigger
Post by: Curtis264 on March 01, 2021, 11:30:32 PM
Here is the assembly, I have been modifying left of the screw that puts pressure on the spring, does not seem to affect the hammer spring pressure
Title: Re: Trigger
Post by: Curtis264 on March 01, 2021, 11:58:27 PM
I was just checking my trigger pull weight, it went from 14lbs down to 3.5 lbs, a little lighter than I wanted but it ignites Winchester large pistol primers just fine, I would have like to stay between 5 - 6 lbs, but the trigger feels good
Title: Re: Trigger
Post by: El Supremo on March 02, 2021, 06:14:17 AM
Thanks, Curtis:

Your included photo helps show the mainspring screw and lower leaf that contacts the sear.

If you can help, please PM me about how you attached the photo. I mostly use a high-end DROID cell phone for emails to avoid lugging a laptop. If anyone else here knows how to attach DROID cell phone stored photo's to Threads here, please PM me.  Tx in advance.

Again, three revered skirmishing rifle gunsmiths that have, but will no longer do Spencer trigger pull lightening for old-age or liability reasons, shared that the heavier, martial 8+# pulls ensure enough finger pressure on the trigger to maintain sear clearance while the hammer rotates.

I have not found a method to consistently "feel" if the lighter pulls allow sear-to-half-cock contact as the hammer rotates. On one I have been able to put the Spencer in a solid rest and carefully apply slowly increasing trigger release pressure while restraining the hammer.  At letoff with no more trigger pressure/movement, the hammer is allowed to slowly rotate while feeling for sear contact at the half cock position. 

In some of mine, with 4.5# pulls, proof of the sear bumping is presented by visible contact spots on the fly, confirming it is both making rotational contact and functioning to prevent bumping.

Spring loaded and digital pull weight gauges instantly release pressure upon the start of hammer rotation and allow the sear to move toward the tumbler, increasing the risk of bumping.  Those styles have more variation in indicated pull weights due to springs or tolerance range in the digital load cell. These mechanical factors creates approx. a half-pound of pull weighf variation. I use only weights, such as the NRA trigger pull weights available from Brownells.  These maintain rearward pressure after letoff.  If a spring or digital gauge is used, fit a hard wood block between the hammer tip and hammer tip recess in the receiver so that upon hammer release, the hammer only trips and moves about 1/8" and does not reach the half cock area. Also, the angle of the pulling against the trigger can change the pull weight several ounces.  Be consistent, preferably from center of trigger, in line with center of butt plate.

Again, Armisport's have a fly, which is a big help, but A'sport tumblers have not interchanged for me in original Spencer's, let alone some other Armisport Spencer's because of dimensional variations spanning years of production in Italy. The Shiloh Sharps tumbler with fly is quite expensive and may not interchange in original Spencers due to minute differences in the flats that index the hammer. The indexing of the hammer may be off enough to interfere with full momentum against the striker slider.  I have been down that road with beautiful Shiloh tumblers.

Each of my Romano Spencers that mirror originals, have been fitted with flies in their tumblers as part of achieving consistent 4.5# pulls. Most were 12# - "exceeds scale limits" before. Larry did not stone sear and full cock notch surfaces to remove the angles that are DESIGNED FOR SAFETY to work against each other.  But -- after a couple hundred releases to see the contact spots, he gently removed any micro roughness on only the tip edges.  No metal was removed! The shim and $60.00 apiece Shiloh mainsprings did the trick.  Larry will not do this expensive work now. 

Most center-fire upper blocks have rearward spring loaded inertia style firing pins that push the firing pin tip behind the face of the bock to prevent tip drag when lowering the block with hammer down.  If there are ignition issues with Win LRP's, check that the firing pin tip is not too short and rests more than 1/16" behind the block face with hammer down fully against striker slider.  Just remove the upper block and push slider full forward to its stop location and look at the hole in the breech face.  I have seen firing pin tips that sat rested 1/8"  back and had less striking momentum.  I have also seen c-f firing pins by the same c-f block maker that varied 1/16" in pin shaft length and striker sliders with significant variations in internal dim's. When I politely inquired, the maker said the striker slider was a prototype that should not have been installed!  Replacement and a slightly longer pin that STILL rested 1/16" short of projecting from the block face worked better. 

Revised for typo's. K

All the best,
El Supremo/Kevin Tinny

Title: Re: Trigger
Post by: Curtis264 on March 02, 2021, 03:25:19 PM
Sorry either I can't find it or I am unable to send PM's but you need to reduce the picture size to 480x640. I also use android and use a program called photo and picture resizing from Play store
Title: Re: Trigger
Post by: El Supremo on March 02, 2021, 04:12:48 PM
Thanks, Curtis:
Big help.  Will look at Playstore.
El Supremo/Kevin Tinny