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View Full Version : Trigger job = lesser reliability?


PapaJoe
06-30-2008, 2:20 PM
I had my 686 trigger changed to a lighter pull. The original was simply too hard for me to get a steady shot off. After I did it, (and I much prefer the pull now), I wondered if lessening the trigger pull also lessened the impact of the hammer on the cartridge and, thus, lessened the reliability that each cartridge would fire. I have not found this to be the case, but the question remains: Does decreasing the trigger pull result in a lighter hammer strike? After all, one is putting is a weaker spring, so it makes sense. Could one ever make a trigger pull so light, given the kits on the market, so that a gun would actually be unreliable?

Cordially,
PapaJoe

461
06-30-2008, 2:38 PM
It can if done improperly. Merely putting in a reduced power spring is not a trigger job, smoothing up the entire action and possibly lowering spring weight if required is a trigger job. If it's done right the hammer impact will still ignite any and all primers and it should be tested to ensure this is the case. I always treat any gun that's had work done to it like a brand new gun and make sure it is completely reliable before relying on it. Over time a spring may weaken but with modern springs it's going to take a lot of time and use before you'll see any issues.

dfletcher
06-30-2008, 2:41 PM
Yes - absolutely.

In fact, getting a smooth and reliable trigger pull from an S & W is a balance of mainspring, trigger rebound spring and parts polishing. Parts polishing aside, a light trigger return spring (let's say 12 lbs) with a full power mainspring is most likely going to result in a trigger that does not fully return or one that does so very slowly - not good is a self defense gun, might be OK on a mostly single action used gun like a 29 or 25. On the other hand, a lighter mainspring with a full power trigger rebound spring will kick back the trigger very nicely - but of course, too light a mainspring and you'll have failure to fire. Lighter mainspring also means slower "lock time" but that's not related to reliability.

kalibear
06-30-2008, 2:51 PM
If its done right, there should be no issues with reliability

mrkam
07-01-2008, 7:21 AM
I had my M&P9 done by Mike Cywrus at accurate-iron.com. Reduced the pull from over 8lbs to 4.75 lbs, with NO spring changes... JUST polishiing and reshaping... it is gorgeous now! (if that is a word that can be applied here!!).

Of course, it depends on the gun, but all of the above is correct, you do not necessarily need to address the springs to lessen trigger pull. There are other physical aspects of the trigger movement and mechanism that may have more of an overall impact. Talk to your smith (or Mike!) about the specific gun, AND the intended use...

TMC
07-01-2008, 11:27 AM
I had my 686 trigger changed to a lighter pull. The original was simply too hard for me to get a steady shot off. After I did it, (and I much prefer the pull now), I wondered if lessening the trigger pull also lessened the impact of the hammer on the cartridge and, thus, lessened the reliability that each cartridge would fire. I have not found this to be the case, but the question remains: Does decreasing the trigger pull result in a lighter hammer strike? After all, one is putting is a weaker spring, so it makes sense. Could one ever make a trigger pull so light, given the kits on the market, so that a gun would actually be unreliable?

Cordially,
PapaJoe


Talking about the double-action pull only, the following applies.

There are 2 springs that work against the trigger, the rebound spring and hammer spring.

Lightening the rebound spring will not effect the hammer energy to set off the primer but will lighten the trigger some.

Once you start to lighten the hammer spring the speed at which the hammer moves is decreased. S&W's with a frame mounted firing pin need hammer speed to set off primers not hammer weight. To help this most revo smiths will lighten the hammer which ranges from simply removing the thumb spur all the way to replacing it with a Randy Lee ultra light replacement hammer. Also replacing the firing pin with an extended version to help with ignition.

As an example my competition 627 with a Randy hammer has a 4.3lb double action pull and will set off Federal small pistol primers 100% of the time. Other primers are harder and the gun is not reliable with them. I've had this trigger set-up in the gun for 3 years with no changes and over 10,000 rounds and its still light and reliable.

Obviously my example is extream and there is allot of middle ground between stock and ultra light.

So the answer to your question is, Yes you can have a really light trigger pull with 100% reliability IF you know what ammo you will be shooting.

If you want it to shoot anything then you should have your smith set up the trigger to set off the hardest pistol primers out there, like Winchester small magnum or small rife primers. Like any modification to any gun, once they are done it needs to be tested thoroughly to make sure its reliable.

Ironchef
07-01-2008, 11:33 AM
Define "reliability."

For some/most it means it'll go bang. If a trigger job (on any gun) is done "correctly" (meaning it retains full functionality), then reliability is not diminished.

Only you can determine that type of reliability by putting it under stress and a 1000 rounds or so.

JTROKS
07-01-2008, 11:47 AM
TMC mentioned something very important. His gun will ignite his ammunition primed with Federal primers. I have done the same back when I was shooting steel and very light target loads with a revolver. Just because you tested your gun with one type of ammo and it's 100% reliable doesn't mean it will be 100% with all types of ammo. The only way to insure reliable primer ignition is to have someone reload you some rounds using rifle primers. If your gun hammer/firing pin ignites that, it should have no problem with any type of pistol primers.

PapaJoe
07-01-2008, 4:24 PM
Thanks for all the empirical advice. The pistol has never failed to fire in the years since I had the modification. Most of the ammo that goes through it is Remington so I don't know how well it would do with other brands. However, I don't ever expect to use reloads or foreign manufacture ammunition so I guess it will be OK. Subjectively, the, "snap", still seems very crisp.

Cordially,
PapaJoe