I am working on my 1954 vintage Marlin 39A that is in excellent condition. (22 Rifire Lever Action)
During disassembly, I noticed that the hammer pivot hole appears to be larger than its mounting screw, allowing sideways wobble.
The screw and hole in the hammer both appear to still have original bluing, so it doesn't appear to be a wear problem.
This rifle has never before been disassembled. I have owned it since it was new!!
Also, the sear notch in the hammer is not parallel with the safety notch. Very strange. Angle of hammer sear is very obvious.
Blackening the trigger sear and hammer sear slot then working the trigger engagement shows engagement across whole sear.
Is that slop common?
Should the pivot screw be replaced?
Should the hammer sear slot be reworked?
Robert Nisbet
Army Research And Technology Protection Center (DAMI-CDS/ARTPC)
Redstone *beep*. AL

You might try this question the Msrlin forum at Rimfire Central.

http://www.rimfirecentral.com/forums/index.php

I would suggest that unless you are having functional problems, to leave it alone.

I'll second gzig5's opinion.
Its a levergun, not a benchrest gun.

I found a Master Machinist who also does precision gunsmith work. We went through the parts and he strongly recommended that the sear be reworked due to possible future failure of the "safety notch" to be able to catch the hammer if the sear should fail.
He made a jig and calculated the proper hammer cut angle. I seem to recall him saying it was 12 degrees. After a re-cut of the hammer sear notch, he made a replacement pivot screw. The replacement screw eliminated the 5 thousandths of play that the original screw has. Play is now about 5 ten-thousandths.
The rifle always had a heavy trigger pull (and creep), somewhere around 8 plus Lbs.
With the corrective action completed, the trigger pull is closer to 3-1/2 Lbs and is totally crisp and solid when the rifle is bumped, jarred, or "whacked" with a rubber mallet.
Wish I had this corrective action done 40 or 50 years ago.
A big thanks to my friend Ron, who spent perhaps 4 hours with me on this project.