H&R 922 Trigger Adjustment

An older Harrington & Richardson Model 922 .22 revolver was presented to me that had a very light trigger pull. Though it functioned quite well as a double action, the owner felt the trigger was too light when cocking the hammer and shooting it in single action. He had purchased the gun at a reasonable price and wanted to know if I could do anything to correct the problem. The Model 922 is a double action, nine-shot .22 LR revolver made by H&R from 1950-1982.

It appears to be a very well-made, solid frame revolver with 2.5 inch barrel threaded solidly into the frame. The gun has plastic As overall hammer release is measured as combined trigger pull force, the three springs that come into play are the trigger spring, sear spring, and hammer spring, which is felt as load let-off friction resistance. This clearance must be maintained for safe pre-release of the trigger. grips which feel good to the hand.

I gave the gun a thorough examination to try to determine why the trigger pull was so light. I removed the cylinder and grips to get a closer look, using Gun Scrubber and compressed air to remove excess crud, but it was of no help. Take up slack of the uncocked trigger showed a pull weight of 21 ounces, which is trigger spring tension taken up before the back surface of the trigger even makes contact with the forward tip of the sear which actually releases the hammer on firing.

Take up slack of the sear spring tension for the first few thousandths of an inch showed only 2.8 ounces pull weight. Mating surfaces on the lifter and sear looked quite sharp and clean, which work together as the gun is fired single or double action. Based on these findings and the nature of its function, I decided to add spring pressure to the sear to supplement the existing coil spring pressure.

This could easily be accomplished by placing a leaf spring between the lower sear tang and rear aspect of the trigger loupe. By design, the lower part of the sear tang fits into a milled out race at the inside rear of the trigger guard. This channel is of adequate depth, 0.8 inch in length x 0.15 inch wide—just right for placement of an added leaf spring.

As a means of pre-testing the function of such an auxiliary sear spring, I placed a temporary piece of flat, curved spring steel between the lower sear tang and the inner race of the trigger loupe. It was a good test of what I could expect from an added spring. Even with this lighter piece of spring in place, overall trigger pull was increased from an erratically lighter pull weight to a consistent four pound pull.

We are reminded here that the overall combined trigger pull weight is a function of the trigger pull itself along with the sear spring pull weight and searto-hammer load friction. The double action function still worked perfectly with the tem-

Above center: Apiece of spring taken from an old alarm clock was used in making the auxiliary sear spring for the Model 922 H&R revolver. porary auxiliary sear spring in place. I then set out to make the perfect spring that would establish about a six pound pull while still maintaining smooth double action function. Making An Auxiliary Spring It required a bit of searching for the ideal spring material.

I finally found just what I needed by robbing the spring from a key-wind style alarm clock, an old "Big Ben." I cut the spring material to size with a sharp tin shears and removed the tem- The tab is shown on the added spring as used to install and remove the spring. Below center: The trigger scale shows the total trigger pull weight which is the force required to release the hammer.

Four springs now come into play, being the trigger spring, sear spring, auxiliary sear spring, and hammer spring pressure, causing friction resistance. Trigger function was much improved with the use of an auxiliary spring beneath the sear. Very adequate accuracy is shown for a short barrel .22 LR revolver. per from one end to shape a small, square corner as a means of holding the spring while installing and removing it.

This enabled me to slide the curved spring into place beneath the sear by grasping the tang with a forceps. With just the proper bow to the spring it could be slid into the race (groove) seat firmly in place just like it belonged there. I couldn’t wait to try it. The little revolver felt good in my hand. I held it with the muzzle pointed to the dirt and cocked the trigger. I had planned to shave the spring down, if needed, for an ideal pull weight but this wasn’t required.

The trigger released at exactly 6.5 pounds and worked smoothly with double action function as well. Repeatedly bumping the cocked hammer with the heel of my gloved hand did not cause the hammer to move forward to the "fire" position. Function Testing I cocked and dry fired the revolver several dozen times and worked it as a double action several times. All went smoothly. Test firing the revolver was next. I shot 18 rounds of CCI .22 Long Rifle Pistol Match ammo at 20 yards.

I really didn’t expect too much from a 1 1/4 pound pistol with a 2.5-inch barrel when shooting offhand, but it did quite well. This isn’t the first time, nor may it be the last, that I have been able to safely improve on the function of a gun. If things don’t work out I never blame the tools. Perhaps the measure of a gunsmith is how some of those tricky tasks are dealt with. AG