Lighter springs causing timing issues?

[m1garand_man]

This is a side bar to my original timing issue thread.

About a year ago I put some Wolff reduced power springs in my 1905 m&p. The gun didn't have a noticeable timing issue before but does now. The only different I could tell after examining the gun last night with the old and new sets of springs in it is that with the 13 pound double action of the original set I had to really try hard to pull the trigger fast enough to cause the cylinder to overdrive past the cylinder stop or lock.

With the 11 pound double action that the gun has with the lighter springs it's much easier to cause to maulfunction.

With that said, this fault really only occurs when I pull the trigger as fast as I can. At a realistic shooting pace the gun doesn't malfunction. It is also fine in single action no matter how fast I cock the hammer.

This leads me to belive that the cylinder stop is timed for heavier springs.

Has anyone else experienced these kind of issues when swapping out original springs for lighter ones?

 

[armorer951]

I would suspect that the problems you are experiencing are because of wear or damage to either the cylinder stop (ball) or the stop slots in the cylinder.
The cylinder stop spring could also be suspect, if you dodn't replace it during the changover.

Have you taken a close look (under magnification) at the condition of the ball of the cylinder stop, the cylinder stop window in the frame, and the stop slots in the cylinder?

If all you did was replace the internal springs (mainspring and rebound spring) with new, OEM ones, this shouldn't have an effect on whether or not the cylinder stop holds, and the spring changes alone shouldn't introduce such a malfunction.

 

[rct269]

I have never experienced the issue you cite---including with a gun with cylinder stop timing altered by the factory. The nature of that timing change is such that the cylinder stop stays down throughout virtually all of the cylinder's rotation---coming back into contact with the cylinder about 3/32" before the lead into the notch---and that's the extent of the "turn ring"----a very light mark beginning 3/32" before each lead---after almost 60 years of use----and the consumption of a boat load of ammunition. It's noteworthy I got a good tongue lashing from Jinks when I told him about this. It went like this: "They never should have done that!! It will cause the cylinder to skip chambers in rapid double action fire." It's also noteworthy about half of that boat load of ammunition was consumed in rapid double action fire----and it has never skipped a chamber.

That said, I'm not even remotely inclined to lay the blame on either the mainspring or rebound slide spring---although I can envision a situation involving the rebound slide spring-----we'll come back to that. Neither has any bearing on cylinder stop timing. I am inclined to lay the blame on a faulty cylinder stop spring and/or the stop plunger (too short) and/or a staggering amount of crud in the plunger/spring bore and/or in the cylinder stop's little corner of the frame recess.

The cylinder stop starts doing its job (goes down) when the trigger tells it to---it starts moving the instant the trigger starts moving. It finishes doing its job (comes back up) when its spring tells it to--and after the trigger lets go of it. I'm somewhat at a loss for words to describe this next possibility as a cause for your malfunction, but I'll take a stab at it. (I suspect you installed your lighter springs so you could shoot faster easier. I suspect that because that's the reason I installed a Miculek spring kit in a 1905 I have----and it's set at a 7 lb. double action trigger pull (and I have no clue as to the rating of the rebound slide spring--but it works just fine).) So-----the cylinder stop starts going down concurrent with the slightest trigger movement. Let me suggest you are allowing your trigger finger to "bounce"---off and back onto the trigger during your efforts to beat McGivern's time-----super rapid double action fire. When your trigger finger "bounces" back into contact with the trigger----Voila!!---the trigger moves. And when the trigger moves the cylinder stop moves---down. And when it's down, it ain't stopping anything!! Now is this because you have lousy trigger finger control---or because maybe your rebound slide spring is a tad on the weak side---or a little of both? I have no clue---just a vivid imagination----or maybe just an overactive imagination. One thing I know for sure and certain (no imagination about it): I can shoot my Miculek spring kit equipped 1905 really fast---faster than I'd have thought possible----but not as fast as McGivern. I have never had any sort of malfunction. So maybe Miculek's spring set is better matched than yours----or something. As an aside, the inside of my gun is SQUEAKY clean---all the parts out and scrubbed SQUEAKY clean. As another aside, the bore of my rebound slide is honed/polished. Does that help? I don't know ---seemed like a good idea at the time---and doesn't seemed to have hurt.

My two cents worth.

Ralph Tremaine

 

[Hondo44]

I still wouldn't call your issue a timing issue, just an Over Travel/skipping issue.

Have you tried trouble shooting as I suggested in your original thread on this?

 

[Pisgah]

Well, let's see, here... a complex mechanical device is designed so that all its parts work in perfect unison in part through the action of carefully-coordinated springs, each with a specific rate and weight specification. Seems to me, the answer to your question "can lighter springs cause timing issues?" just might be, yes.

Then again, maybe no. But if a contraption works perfectly before I change something, and not perfectly after, I'd take it as a possible clue.

As for wear of parts being a potential cause, of course that is a possibility; but it's also a consideration that the original spring weights and rates are calculated to compensate, to a degree, for normal wear, at least up to a point.

 

[Hondo44]

The difference in this case is that the different spring tensions are not directly related to the problem. They are only indirectly associated because they're not directly causing the problem, they just facilitate his trigger finger to be able to operate the DA faster which causes the cyl stop to jump the cyl notch.