My M-18 has a trigger stroke that stacks in the middle of the pull. It starts out ligth, gets heavy in the middle, and then lighter at the end.

I would like it to stack at the end of the pull, if at all.

Would a new mainspring help? or bending the mainspring? If bending the mainspring would help, how do I do it?

much thanks in advance,

This message has been edited. Last edited by: hitecrednek,

Don't take this wrong, but that sounds more like a dirty gun than a spring issue.

Is the forcing cone face and the cylinder face absolutely clean? When is the last time the cylinder has been removed from the yoke and the bearing surfaces of the yoke cleaned and oiled? Both of these conditions can give you the same "stacking" sensation.

This is especially true with the .22's.

Nice and clean; I shoot it a lot and clean the gunk out fairly often.

quote:

Would a new mainspring help? or bending the mainspring?

Short answer, not at all.

My money is still on dirt, dry spot in action, or burr. Unless damaged, the mainspring does not affect smoothness of pull but weight. Check hand and star for openers. Are all places metal bears on metal smooth, clean and lubricated properly?

Things I can think of, the spring doesn't have enough tension or bend in it (couldn't be the wrong spring could it?) and it is doing what my 'smith called knuckling over. This can happen when the tension screw is backed out a bit on some of the guns. The spring is installed fully down into the slot in the frame right?
The spring isn't by chance hitting the grip screw during it's bending is it?

Another thought is that there is a 'lil dirt under the extractor star and it's causing other problems.

Or, if an old and/or light spring, the spring contacting the inside of the grip frame. (Don't laugh, had it happen!). Everything the folks spoke of could cause a change in the geometry the spring's designed to follow. Have you tried drawing it through it's travel with the grips off? Did it change, or stay the same? Also, if the problem goes away then, put the grip halves back on w/o the grip screw and try it.

Too many possible options as to why you are having this "issue". If it has been going on from day one and you bought it new then I'd contact the Factory. Other than that I'd suggest you find a good Pistolsmith in your area or again contact the Factory for repair.

quote:

Originally posted by hitecrednek:
My M-18 has a trigger stroke that stacks in the middle of the pull. It starts out ligth, gets heavy in the middle, and then lighter at the end.

If you mean on a DA pull: that is the classic symptom of an improperly fitted DA sear. In the middle of the stroke, the trigger transitions from lifting the tip of the DA sear to lifting on the porch below the SA sear. If the DA sear is fitted wrong, it will bind in the transition.

I'll strip it and give it a very good cleaning (did I clean the hand window good enough?), and if it still does it send it on vacaction to Springfield....thanks again for the suggesting things to look for.

I, uh, ahem, did miss a spot in cleaning...problem solved.

No soup for you!

Glad you figured it out. Out of curiosity, where was the spot of gunk?