[MadMax]

Check to see if your trigger sear disconnector feature of the trigger group is working properly.

The disconnector is the funny tab sticking out the top of your frame on the right side just forward of the hammer (pistol pointing away with slide removed). When the slide recoils about 3mm, it's pushed down by a surface in the recoil block in the slide. When the disconnector is pushed down by the slide the entire piece moves down so the trigger loop does not bear against the hammer sear. The disconnector has a side protrusion which sits between the trigger loop and the sear. When it's pushed down by the slide, the trigger loop is decoupled from the sear so it allows the sear to rotate and retain the hammer even with the trigger pulled. The leaf spring pushes the disconnector upwards via a triangular feature at the bottom of the disconnector.

If the top of the disconnector is severely worn, it does not push down far enough do disconnect the trigger loop from the sear so the sear is not allowed to retain the hammer.

You can diagnose this problem by removing the hinged grip safety (sometimes called a beavertail grip) and manually actuating the gun according to the following scheme:

Remove the grip safety and test on an otherwise reassembeled gun. Put an empty magazine in the grip (no gas). Lock the bb follower down with a wad of paper so the slide lock doesn't lock the slide.

1. Cock hammer

2. Grip frame in a way so you can look into the trigger assembly

3. Pull trigger to release hammer and keep trigger pulled

4. Manually retract the slide slowly keeping the trigger pulled. Pull the slide upwards while pulling it back. This simulates a worst case condition where the slide pushes down on the disconnector the least because the slide is tended to the top of the rail grooves.

5. Look to see if the disconnector is pushed down far enough that it does not stack between the trigger loop and the sear. It should drop out allowing about 2mm of clearance so the sear reliably engages the hammer

If the sear does drop completely out of the way yet the sear still does not reliably engage, your rear bow on the trigger loop may be bent too far rearwards. On some custom tuned triggers, the gunsmith may have bent the trigger bow too far so the sear is pushed far enough that the hammer is not retained even with the disconnector depressed. Bend the rear bow forward slightly to fix this. Bending the rear bow rearwards reduces the small amount of play before the trigger loop starts to rotate the sear. A small amount of play is necessary to allow the disconnector to pop back up when the trigger is released to reconnect for the next shot, but it's possible to shorten a trigger action with some trigger loop tweaking. DO NOT FILE OR SAND TM Hicapa sears or disconnectors. While it is tempting to customise the shapes of various surfaces for super short sharp trigger pulls, you will remove the heavy chrome plating TM puts on their cast aluminum trigger bits. This finish is not cosmetic. It reduces friction and acts as a hard wear surface which is much more durable and low friction than bare aluminum (I wish WA would learn something from TM here).

Watching the trigger sears with the beavertail removed can also show other problems like a sear not rotating smoothly. If the leaf spring isn't doing it's job, the sear tip will not be sprung against the hammer engagement surfaces. If there's too much crud in the mechanism, the sear may not rotate freely.


I think that's about all I can think of that might cause your hammer to not lock back.