Advice requested on M&Pc Trigger

[ncgreyhound]

I just acquired a 45c and I'm very disapointed with the trigger. I already own and shoot a Shield 9, 9c, and a 9FS. I'm happy enough with the trigger pulls on all on the 9s and haven't felt at all compelled to have any work done on them, especially once I put several hundred rounds thru each. The 45c is quite another thing. I've only dry fired it but the take up is smooth, effortless until the end of the trigger pull and it then suddenly takes quite a pull to snap. It almost feels like the trigger is flexing (stressing) as it fires. My first impression on my initial dry firing was that the safety was engaged. No trigger pull gauge so I can't quantify the pull. I just know it feels absolutely nothing like the 9s. I plan to call S&W for their take but not sure what to expect. I have no experience with the Apex kits but I'm not sure they were designed to correct this. I would appreciate any thoughts from this M&P experienced crew. many thanks.

 

[blujax01]

Good Morning!

I bought a 45C last month and had the same concerns. After I read somewhere that S&W puts a dozen rounds through each new M&P then boxes them dirty I took mine down, gave it a good cleaning, oiled the oily parts, greased the greasy parts and shot 100 rounds of 230 grain ball through it. The trigger feel got progressively better as the session went on.
Brought it home, took it down a second time, cleaned, oiled and greased it and went to the range again this past Wednesday.
After the second hundred rounds, it's as smooth as my Colt Government 1911. Not "Performance Center" or "Custom Shop" perfect but much improved and good enough for a $500 gun.

Next up - 185 grain Nosler hollow points!

 

[Ranger98]

I installed an Apex hard sear in my M&P45c.Made quiet a difference in the trigger pull as well as the reset.

 

[Wee Hooker]

I installed an Apex hard sear in my M&P45c.Made quiet a difference in the trigger pull as well as the reset.

x2 but on a full sized M&P45.

 

[southchatham]

You might have one of those 10lb trigger guns made for certain states like MA.

 

[Dean1818]

Burwell diy trigger job will help

VERY easy

30 mins max

 

[blujax01]

At least give the guy a chance to put some live ammunition through it. His assessment is based on dry firing only.

 

[robkarrob]

ncgreyhound

Dry firing is going to give you the trigger feel. If it dry fires badly, it not going to get any better on the range. Sure if it is burr problem, eventually it will wear away, if you want to wait that long.

First you should try to diagnose the cause:

You said it pulls smooth to the I am guessing the pick up of the sear, about the last 3/16 inch of trigger pull.

1. Remove the slide and test the trigger pull, should be OK.

2. Put the slide back on, cycle the slide to cock the striker. Put a small object (precision screwdriver, long small diameter pointer, etc.) in through the rear slide cover, the small opening on lower right side. You have to go in about 1 inch and you can lift up on the striker blocker ( I use a fulcrum by pushing down on the top of the frame to cause the item to lift the blocker, see photo). Hold the blocker up and pull the trigger. We are trying to eliminate the blocker in the trigger pull. If when you pull the trigger you feel the trigger bar hitting on the item you are using to hold the blocker up, move that item over or use something smaller, as the trigger bar should not touch that item.

Once you can pull the trigger, with the striker cocked, and the blocker pushed up out of the way you can diagnose the problem. If the trigger pulls smoothly to break, the blocker is the problem. If you still have the trigger pull problem, then it is sear related.

post your results and hopefully we can get it fixed.

Bob

 

[ncgreyhound]

Thanks all

I can tell it has been factory fired but looks to be pretty clean already. I see no gunk. I checked the box and the sku is 109308. I don't believe that is a Mass 10lb trigger model. Note in my original post, I was speaking figuratively about the safety being engaged - this is a no safety model.
Robkarrob - yes it is the last 3/16th or so that requires the tug. The trigger operates cleanly without the slide. I held up the blocker as you suggested. The trigger pull doesn't seem any lighter doing this. So that means the sear? I certainly don't mind running some rounds thru it but it again, it kinda freaks me since the trigger seems to be almost straining thru the pull. Thanks again and I look forward to further diagnosing. tks,

 

[robkarrob]

ncgreyhound

We have determined the problem is in the sear. However it may also be striker related. Since the trigger pull was not "heavy" with the slide off, this tests the trigger and sear spring pressure. Pulling the trigger with no slide, the trigger bar still contacts the sear and lifts the front of the sear, causing the sear spring to compress, and the trigger spring is tensioned.

So the extra pressure is between the sear and the striker contact. I am not familiar with how S&W makes the MA mandated or LE higher pull weight triggers. I would have thought they would use stronger trigger springs or stronger sear springs or a combination of both. But the test rules that out. The trigger pull was fine with the slide off. You had no pressure relief with the striker blocker manually lifted.

The only other option would be increasing the "bump" on the sear and or adding a bump on the striker face. Or they may have increased the spring pressure on the sear spring. Since you have other M&P's you can make an easy check. Compare the sear face and striker face with your other M&P's. You are looking for a more pronounced bump on the sear (at the top rear of the sear) and or something added to the striker face (instead of the flat smooth face). Next is the striker spring pressure. With the slide off push the striker fully to the rear, feeling the pressure. Then try to compare that pressure with the other guns. You should be able to feel a higher pressure. The striker spring does not need to be higher for different calibers. Make sure the mating faces of the sear and striker are clean and smooth. Add a drop of oil or grease on the faces and test the operation again. Keep us posted on your findings.

I am thinking you got one of those higher pressure trigger guns.

Bob

 

[blujax01]

Okey Dokie.

Don't lubricate your new gun.

Don't put any ammunition through it.

Jump right to an aftermarket trigger/sear job.

Out.

 

[insomniac]

The 45c is quite another thing. I've only dry fired it but the take up is smooth, effortless until the end of the trigger pull and it then suddenly takes quite a pull to snap. It almost feels like the trigger is flexing (stressing) as it fires.

the trigger on my full size M&P45 was exactly as you describe. trigger parts would actually flex and it was impossible to keep the front sight on target when the striker was released.

installed Apex hard sear and now it's very nice, prob around 5 lbs or less with a clean break.

i think mine must have been a Mass compliant pistol with 12 lb trigger

 

[Maddmax]

At least give the guy a chance to put some live ammunition through it. His assessment is based on dry firing only.

I have to agree. It needs rounds down range to get broke in. If not,call S&W support and tell them about it.. New weapons and "new" (to M&P) model owner always have the same problems.

 

[ncgreyhound]

Update

I was unexpectedly able to live fire the gun today but only about 70 rounds. Mine is not quite as bad as what Insomniac described. I was able to hold it steady and shoot very accurately. I do think the trigger pressure eased up some since I don't feel quite so much flex in the trigger now.

Rob, I don't see any difference in the sear or the striker as compared to my 9c. As far as the striker spring, did you mean push it forward rather than to the rear? If so, I felt no pressure difference there either between the 9c and the 45c. Appreciate further thoughts. tks

 

[robkarrob]

ncgeryhound

Yes I did mean pushing to the rear, like it would be when cocked and held by the sear. You have done all the tests to isolate the problem, and nothing in the tests has shown any higher pressure, but you still have the higher pressure pull.
You have tested the pull:

1. With the slide off which isolates the trigger return spring and the sear movement and sear spring.

2. Slide on and striker cocked. You pushed the striker blocker up and pulled the trigger. This took the blocker out as the cause.

3. Checked the sear bump and striker, comparing to your other M&P's, and checked the striker spring pressure. Nothing was different.

I am at a loss as this should have allowed you to find the location that is causing the extra pull pressure.

Last check, which will not likely show anything. Slide cycled to cock the striker. Pull the trigger and you have the high pressure pull to break. Once the sear has released the striker, pull the trigger fully and I would guess the pull feels normal pressure, not the higher pull pressure you have been having. If this is correct then we know the pressure happens when the cocked striker is being held by the sear. There is always going to be slightly higher pressure as the spring pressure of the striker is causing higher friction between the sear and striker. That is why I suggested making sure both faces are clean and adding a drop of oil or grease on the faces.

While your at that, clean the sear loop and sear lobe and add a drop of oil/grease to both. Not much else I can suggest. Just check that the trigger bar tail is not somehow bent and not entering the guide opening in the sear housing properly.

Bob

 

[ncgreyhound]

Rob -

can you check your PM thanks

 

[Dieselscout80]

One thing I've noticed with the slide off as I squeeze the trigger the trigger-bar moves sideways before it starts to move to the rear. If I keep the trigger-bar from moving sideways (to right when viewed from rear) the trigger squeeze seems to be much smoother.

I've never heard this mentioned by anyone.

I wonder if a bearing surface on the frame or the slide release would prevent this or maybe just some grease the trigger bar where could prevent the draging and let it move smoothly?

WP 20121031 022259Z - YouTube

 

[Racerg]

ncgeryhound


1. With the slide off which isolates the trigger return spring and the sear movement and sear spring.

2. Slide on and striker cocked. You pushed the striker blocker up and pulled the trigger. This took the blocker out as the cause.

3. Checked the sear bump and striker, comparing to your other M&P's, and checked the striker spring pressure. Nothing was different.
...
Last check, which will not likely show anything. Slide cycled to cock the striker. Pull the trigger and you have the high pressure pull to break. Once the sear has released the striker, pull the trigger fully and I would guess the pull feels normal pressure, not the higher pull pressure you have been having. If this is correct then we know the pressure happens when the cocked striker is being held by the sear. There is always going to be slightly higher pressure as the spring pressure of the striker is causing higher friction between the sear and striker. That is why I suggested making sure both faces are clean and adding a drop of oil or grease on the faces.

While your at that, clean the sear loop and sear lobe and add a drop of oil/grease to both. Not much else I can suggest. Just check that the trigger bar tail is not somehow bent and not entering the guide opening in the sear housing properly.

Bob

Bob,

Thanks for the workflow. I like your way of thinking through and determining the problem.

One thing I noticed is that if you pull the trigger with the slide on you can actually look in the gap at the rear of the slide and frame and see the sear and striker block move as the trigger goes through its travel. It helped me verify that the roughness was in the striker block and not in the sear.

Racer


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