Sear spring tension

[Stan Hillis]

I have an early Sterlingworth ejector gun that I have refinished, stripped and cleaned, and reoiled. I added some tension to the sear spring when I reassembled it ...... and now regret it. The trigger pulls are off the chart now. It is a 12 ga. gun with 30" barrels, and the triggers will hold the gun up now. You have to "bounce" the gun on the trigger to get them to break. Easily 9-10 lb. pulls. I have to disassemble it now and mess with the spring until I get it back where it was before disassembly. I am going to measure these pull weights before and after to quantify just how much the sear spring can affect it.

I have done a lot of trigger jobs in my life on my own guns ......... pistols, rifles and shotguns. But, I never saw the sear spring make so much difference. I must have really put a lot more tension on it for the trigger pulls to have escalated like they did. Before anyone asks, nothing else was changed with the internal parts. Anybody have advice for getting the tension close to right before reassembly, or is it just totally trial and error? My plan, in lieu of helpful advice, is to relieve tension to the point that I have just a little more than is needed to raise the sears into the hammer notches when cocking.

Live and learn.

SRH

[J. A. Early]

I am very interested in your question because I too have an A grade Fox that it takes two men to pull the right trigger. But I did not think it was caused by the sear spring since the pressure on the spring after the hammer has been dropped is the same for both barrels. I did not know the spring could be "adjusted," but instead was just put in place. I am sure one of my hammers was replaced because of the difference in appearance from the left hammer, and I blame it on the mating surfaces of the sear and hammer never having been fitted, just a new/different part being put in. I hope a good Fox smith will reply for I too need to fix my A.

[Stan Hillis]

J.A., the sear spring is a two pronged flat spring that has two legs that bear upon the two sears, pushing up against them. Each leg can be adjusted by bending it so that it bears harder, or less hard, on the sear.

This certainly isn't the only thing that can cause a hard trigger. You may well have an ill fitted hammer/sear relationship.

I had to install a recoil pad today for a friend, and haven't gotten around to readjusting mine, but will soon.

SRH

[J. A. Early]

Stan,

The reason I say my problem is not the sear spring is because the spring is the same for both triggers, and the left is a fairly normal pull. During disassembly, with the spring backed off by loosening the screw and the hammers cocked, when I press the sears to uncock the gun with my finger, it is extremely hard on the right barrel, but not on the left. With the spring the same both sides I don't think relieving the tension will help.

Thanks for the reply.

[Stan Hillis]

I agree. You need a good trigger man. It's tedious work.

SRH

[vaturkey]

I had Dan Rossiter fix a doubling Fox for me. Took him about 30 minutes to get it just right where it wasn't too heavy or too light. It did involve some rather tedious file work and assembly and disassembly a few times to make it right.

[Stan Hillis]

Okay, I didn't miss it by much with my guesses. Got a trigger pull gauge in today, and they are 9 lbs. on the front, and 7 3/4 lbs, on the rear, triggers. Maybe tomorrow I will get the chance to adjust the spring pressure and see what it does.

More to come......

SRH

[Stan Hillis]

Got them back to 6+ on the front trigger and 5 1/2 on the rear just by lightening the pressure on the two sides of the sear spring. It is going to take further trigger work to improve on that, but I will do it. Still a bit heavy for me. I want to get them down below 5 on both.

For some reason the sear spring on the front trigger sear is stronger than the one on the rear trigger sear. Even when you bend them until they don't even make contact with the sears, then pull the triggers against them with the gun uncocked, it is much stronger.

SRH

[J. A. Early]

Well, broke my sear spring trying to reduce the tension. Looking for one, early A but I guess they were the same even on the Sterlingworths. Let me know if you can help me out.

[Stan Hillis]

Sorry that happened J.A. Hope my post did not cause it.

My next step will be stoning the sear and corresponding hammer surfaces. One trick I use for doing a trigger job on guns that require so much effort to remove/replace the hammer and sear is to cut a piece of plexiglass about 3" x 5", and using the pin holes in the side of the receiver as a guide, drill corresponding pin holes in the plexiglass. It is imperative that the sear and hammer pins be a snug fit in the holes, or all is for naught. Then, you can remove the hammer and sear and install them on the plexiglass so that you can get a much better look at how they fit together when engaged. With some guns they will lay on the plexiglass in perfect alignment but, on others, one or the other part may require shimming. This can save a great deal of time as opposed to installing and removing them every time you hit them a few strokes with the stones. It is still no guarantee that you have them perfect before reinstalling in the gun, but it makes the job a whole lot easier, IMO.

A bonus is that, if you're lucky, the next gun you do of the same make/model will have the same pin placement, and it won't be a one time deal.

(Disclaimer: Working on triggers is something that I do for myself, and I cannot recommend that anyone else do so.)

All my best, SRH

[bbman3]

Great idea Stan.Bobby

[J. A. Early]

Stan,

Your post had nothing to do with it. I should know by now that one cannot bend spring steel but so far. I have one on the way from Jason Barden at Pumpkin Mtn. The plexiglass is a great idea.

[Stan Hillis]

Thanks, J. A. Still sorry yours broke. We have a great resource in Jason. Good luck.

SRH

[Silvers]

So let's use a teeter totter analogy to illustrate. You have a small teeter totter and at one end you have an 6 pound weight along with a 2 pound weight. The other end of the TT has no weight, thus it would take 8 pounds to get it to balance and a little more (8+ pounds) to get that end to tip down. Then you reduce the 2 pound weight to 1 pound. It now takes 7 pounds to get the TT to balance, and 7+ for it to tip.

OK, so in this simple analogy the TT is the trigger sear and 8+ pounds represents the force required to get the hammer end of the sear to overcome the hammer spring/mainspring. And the 2 pounds represents the effective force applied by the sear spring. Hence it can be seen that bending a leg of the sear spring to make that force 1 pound, will do little to reduce the force required on the opposite end to get the hammer to release, i.e., the trigger pull.

Best advice I can offer here is to get a SxS professional to work on your Fox if you want a lesser (or greater) trigger pull. It's too easy to goof it up by experimenting and I've seen so many Foxes like that over the years. Usually the ones have been goofed up can't be redone without replacing the hammer or the trigger sear, or both, with NOS parts and then starting over. Of course all this is JME gents.

[setterspell]

Dumb question- if the point where the spring touches the sear is closer to the axle, wouldn't it take less effort to trip the sear?