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SMP · Silver Status Member

My 1377 is retaining air again so I stripped it down for a thorough cleaning and inspection.
What I found is the woodward sear is colliding with the groove in the hammer as it flies by. There is a nice little hammer forged flat spot in my fancy sear sear to prove it.

I may be able to lightly smooth the spot with a diamond stone but I'm wondering if anyone has had this issue and corrected it

Should I relieve the area on the hammer the sear is making contact with? Effectively shallow the angle of the groove at that point so the sear slides by?

I think whats happening is the trigger pull is so light that there isn't enough force being applied when the sear releases to pull it all the way down.

rsterne · Moderator

Possibly you have the overtravel adjusted too fine and the sear can't move out of the way completely?.... I had the same problem with a Disco sear after I added the travel screws and it caused extreme velocity variation as well....

I don't know how you adjust the overtravel on a Woodward sear, but sometimes on a 22XX it's done with a spacer on the spring.... Spacer too long = sear won't clear....

Bob

SMP · Silver Status Member

That sear is the "woodward Non Adjustable" from Eric. There is no travel adjustment and I haven't added any yet. If I fully pull the trigger it will completely disappear but the gun fires at a hair over a touch.

But ultimately whats your thoughts on the hammer. Do you see any problem with blending that spot on the second groove so there isn't a flat face for the sear to contact?

rsterne · Moderator

I think the hammer contacting the sear is going to give you erratic velocities.... or at least reduced velocities.... compared to if it wasn't hitting....

Putting a shallow taper on the bottom of the hammer where it's hitting with a grinder and then polishing it might work.... or it might still drag....

There is no reason you can't cut a slot in the bottom of the hammer to completely clear the sear from immediately behind the release point right out through the back end.... or at least past the maximum possible travel with the valve open.... The hammer is case hardened (or at least hardened) which is too bad, otherwise you could just mill a slot.... I'm guessing you could grind one, though....

Bob

SMP · Silver Status Member

I have a nice little diamond cutter for the dremel. I think I'll strap that onto the cross slide a have a go tomorrow.

Backwoods milling 101

rsterne · Moderator

Worth a try.... Mr. Green

Bob

AirGunEric · Site Admin

If you have the adjustable unit- it is mal-adjusted. I have seen this before, and the claim by Woodward that the sears are "pre-adjusted" is BS. Back the adjustment screws all the way out and start from there.

SMP · Silver Status Member

I am finally able to post the conclusion of this thread.

I reassembled the gun several times and took video of the sear as the gun fires.
With the trigger spring set feather light you can see the sear drop a tiny amount then bounce as it passes the groove.
With the trigger spring adjusted firm the sear drops much farther initially and no bounce.
So it is possible to set the trigger so light there isn't enough inertia in the trigger pull to get the sear out of the way.

I ground a groove in the hammer 1/8" longer than the travel. Reassembled and the velocity is back and it's not retaining air.

The woodward sear however is not as perfect as it was when new even though I very delicately smoothed the sear as close as I could to the original arc.