M305 trigger job.

romurra

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Vancouver BC
Working over an M305 trigger group with the “Hungry” trigger job (lapping compound on trigger hooks, dry fire trigger group 100s of times to polish hooks) I find one hook is polishing up nicely, the other is untouched. While the trigger is much improved, I’m wondering if obtaining USGI parts will deliver a trigger group that bears on both hooks, and perhaps improve the trigger ‘feel’.

I don’t think continuing to polish to get both bearing will be in my best interest as the first hook to bear will likely get past the case hardening on the parts.

Share your advice and experience please, is it usually the trigger, hammer and pin that deliver this imbalance or is it the actual trigger housing (such that a new trigger and hammer set won’t help)?
 
if you can find sections of drill rod that are straight and true and the same size as the hammer pin and sear pin you can check for angled holes using a small machinists square.
It's about the only way I have found to reliably check if the holes were milled true in the housing. I have seen many that weren't , a few springfield armory but mostly Chinese. New parts won't help, a new housing will be the only real option.
 
thanks for the excellent tip, there is more where that came from. somewhere in there is a book. too many people take their knowledge to the grave with them.
 
Dismantled the trigger group. The cross part at the top of the trigger the hammer hooks bear on is out of true by about 5°, and the hammer release hooks are out by about 3° (In opposing directions, of course). No way I can polish that into an even engagement!

Hole in trigger group housing looks good, within a degree or so. I think it’s close enough for the girls I plan to date.

Have ordered new trigger, sear, hammer, hammer spring and associated pins from Numrich gun parts. NOS USGI, should be a vast improvement.
 
It’ll be night and day.

When I do a NM trigger modification on a Chinese housing, I always replace the hammer, trigger and sear and pins with usgi at minimum. The spring, housing and plunger are good to swap to.

Polish all the contact points before reassembly, this includes the stem and nose of the plunger and use moly grease.

Jon
 
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