Two new Shields.. Two different trigger pulls ?

DeeBee

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I have two newer Shields in 40, and one has a very nice trigger pull and break, the other has a nice pull but it feels like it has about a 1-2 lb. heavier break. (its noticeable).
What would cause this? The sear?
I swapped uppers and have narrowed it down to the lower being the problem.
Any ideas?
 
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I have two newer Shields in 40, and one has a very nice trigger pull and break, the other has a nice pull but it feels like it has about a 1-2 lb. heavier break. (its noticeable).
What would cause this? The sear?
I swapped uppers and have narrowed it down to the lower being the problem.
Any ideas?

Wow. If you narrowed it down the the lower, I am not sure. How does the trigger bars look (more particularly the looped part that move the sear)? The only thing I can think of, off hand, is one of the loops being different in size (which can be adjusted) or a sear being a bit different in the rear. We're they both new?
 
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Wow. If you narrowed it down the the lower, I am not sure. How does the trigger bars look (more particularly the looped part that move the sear)? The only thing I can think of, off hand, is one of the loops being different in size (which can be adjusted) or a sear being a bit different in the rear. We're they both new?

Yes, both bought new. Everything looks good, and smooth.Like I said the initial pull is good, it just has a heavier break?
 
I see your on the East coast. Any chance you got a MA trigger I one of them?

The one feels like a 5lb trigger and the other feels like an 6-8 lb.? The both are the same part number.
I just wonder if I send it back,if they will say it is in specs, and do nothing?
 
How many rounds through them? If none, it could be a break-in issue. The metal parts are punched at production with very little de-burring if any at all. That's were a little break in helps.

With out a doubt I would put a few hundred rounds through them before thinking of sending them back, for the reason of checking for other issue alone.
 
Your swapping the slides eliminates a lot of other likely causes. Since one of your lowers is causing the higher trigger pull issue, then there is only a few things: something dragging, the sear face, the springs, the trigger bar blocker tab. Since you diagnosed it to the lower, my first question is there any noticeable difference to the pull with the slide off? This would show a difference in the trigger spring, sear spring, and dragging. If there is no difference there, I would think either the sear might have a rough face, or the contact area between the blocker tab and blocker might have a bad/rough surface, either could increase the pull pressure. I would doubt these would cause 2+ pounds increase in trigger pull, but if the others check good, there are not many other things to cause the difference in pull pressure, since it is not coming from the slide components.

Bob
 
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How many rounds through them? If none, it could be a break-in issue. The metal parts are punched at production with very little de-burring if any at all. That's were a little break in helps.

With out a doubt I would put a few hundred rounds through them before thinking of sending them back, for the reason of checking for other issue alone.

The one thats nice has about 200 rounds through it, and the heavy one has about 500 through it.
 
Swap the sears and see how it feels

Thats what I would like to do, but would hate to take all that time. And if that is the problem, what do I do then? Iam telling you the nice one almost feels too nice??.. like maybe a 4.5lb trigger break. I wish I had a guage.
 
Thats what I would like to do, but would hate to take all that time. And if that is the problem, what do I do then? Iam telling you the nice one almost feels too nice??.. like maybe a 4.5lb trigger break. I wish I had a guage.

I highly doubt either are that low. Suppose to be 6.5. Mine felt crazy light I thought. Used a trigger pull scale and got 6.4lbs. I think your finger scale may be off. ;)
 
Thats what I would like to do, but would hate to take all that time. And if that is the problem, what do I do then? Iam telling you the nice one almost feels too nice??.. like maybe a 4.5lb trigger break. I wish I had a guage.

Can you see the backs of the sears? Does one look like it curves back less? There could be a chance that you got a lightly used Shield sold as new that had a sear upgrade. My trigger pull is 4.5 w/ the Apex sear installed.
 
You may have 2 different sears. My Shield has the old mim sear even though it was a test fire date 5-13, my 9c has the newer production sear but has a test fire date of 3-13.
 
Status on these Shields. Did you buy them new, one new and one used, or both used? The idea that you don't know if either has been modified may be the difference.

Bob
 
You may have 2 different sears. My Shield has the old mim sear even though it was a test fire date 5-13, my 9c has the newer production sear but has a test fire date of 3-13.

How can I tell the difference?
 
There is a thread "Articles - M&P Production Updates: Slide Stops, Barrels, Sears" down the page a little bit, it shows the difference in shape between the sears. You can see the shape of the sear by looking at the trigger group from the right sight of the gun with the slide off.
 
New Shields with different pulls

If all the checking and comparing don't answer the issue, I'd call S&W, ask them if either the serial numbers were for the Massachusetts market. I've seen other posts elsewhere that said two Mass. Shield models had been sold in two different States somehow.
 
There is a thread "Articles - M&P Production Updates: Slide Stops, Barrels, Sears" down the page a little bit, it shows the difference in shape between the sears. You can see the shape of the sear by looking at the trigger group from the right sight of the gun with the slide off.

I missed that post. Thanks for pointing that out. That could very well be the issue. Nothing an Apex sear couldn't fix, if he does have on old sear. ;)
 
If the tests I explained check negative for a difference, then the sear or the blocker tab are causing the difference in pull. With the slide off, check the shape of the top rear of the sears. Do they both have the bump/lip at the top rear? This bump adds one extra pound of pulling pressure. If they both look the same, check the shape/smoothness of the blocker tab, the pointed tab that sticks up from the trigger bar (bar that runs from trigger to sear on the right side). You are looking for a difference between the two guns.

Bob
 
I bought one maybe 4 weeks ago. I handled at least 6 at the gun show and later bought one from LGS (after handling at least 3). As I recall triggers felt different on each one. A lot of them had a very bad feel with very gritty triggers and weights seemed to vary. Finally found one I liked and bought it. Even on that one when travel ends its a fair amount of weight to actually fire. Its also a fair amount of travel to reset and then a very distinct/loud click. An Apex carry/duty kit and a quick polish of the contact surfaces is in order. Even with the Pro doing the same with a Apex comp kit (original w/o trigger, trigger spring or extractor) the difference is night and day in travel, break, reset and its just plain smooth.
 
I think I have narrowed it down, to either the loop on the trigger bar or the sear. When I pull slowly on the trigger with the slide off, I can feel roughness when the loop pushes up the sear. My other Shield is like butter. Welp,I guess its back to S&W. Hopefully they will fix it right.
I just cant justify spending $100 for an Apex kit,when the gun was $389. (and that may not fix it if it needs a trigger bar), Thats just me.
 
M&P sears have gone from a MIM part to a machined part through what is known as a rolling change. They simply waited until the MIMs were depleted and switched to the machined sears. It could be that your Shields have one of each. The difference in the sears is said to be dramatic.
 
I think I have narrowed it down, to either the loop on the trigger bar or the sear. When I pull slowly on the trigger with the slide off, I can feel roughness when the loop pushes up the sear. My other Shield is like butter. Welp,I guess its back to S&W. Hopefully they will fix it right.
I just cant justify spending $100 for an Apex kit,when the gun was $389. (and that may not fix it if it needs a trigger bar), Thats just me.

You are gonna send it back for that? Well, you do have two. :)

That loop can be adjusted. Also the Apex sear is only $40 or so and will get you around 4.5. You only really need the sear. The full kit is $100 or so and will give you a 5.5 pull.
 
My Shield has the mim sear, my 9c has the machined sear, I do prefer the pull on my 9c but I wouldn't say the difference is dramatic but it is enough of a difference that I don't get the front sight twitch when dry firing the 9c, better accuracy.
 
They haven't had the Shield armorer class approved yet (last I heard), but you ought to take into consideration that the normal factory spec for the M&P pistol trigger pulls involve an acceptable +/- 2 lb range.

These are "parts-is-parts" guns, and when you factor in the acceptable range & "stack" of tolerances for the various parts & assemblies, the trigger pull in any particular gun can vary within an expected weight range.

I've handled and used a fair number of M&P's since they were first introduced. Some initially had heavy, stiff & gritty triggers which smoothed out & lightened up with use ... and some started out nicely smooth and on the lighter end of the normal tolerance range.

Shooting the gun is the easiest way to "smooth out" trigger pulls. ;)

These are "defensive" guns, not custom guns with hand-fitted triggers.

If you think something's "wrong" with your Shield 9, ask for it to be checked by the company, don't screw around with it yourself. Maybe one of the techs will take the time to try a couple of trigger bar assemblies in your gun to see if he can find one that gives a pull on the lighter end of the normal range.

(It also wouldn't hurt to check the box label and make sure you haven't received a MA-compliant gun, too.)
 
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My Shield has the mim sear, my 9c has the machined sear, I do prefer the pull on my 9c but I wouldn't say the difference is dramatic but it is enough of a difference that I don't get the front sight twitch when dry firing the 9c, better accuracy.

I look forward to dry firing one with the new sear for comparison. My Shield 40 with a 4/15/2013 test fire date has the MIM sear. It has always felt pretty good. The first Shield I handled felt horrible, but I placed my order anyway. I wanted the smaller package and hoped for the best. My friend ordered a Shield 9 that day, and his feels better than the one we got to handle. I'm glad our MIM sears and other parts' stack up within tolerance to feel good. I don't feel cheated not having the new sear. Hehe.
 
UPDATE: I bought a Timney trigger pull guage. My"good" Shield measured exactly 6 lbs. the "bad" one measured 7 lbs. I am telling you, that one pound is like night and day.
I took the sear assy out and hand polished all the moving parts.... trigger pull dropped to 6 3/4 lbs. :( Wrapped it up and sent it back to S&W. I hope they can get it to 6 lbs. My trigger finger is hurting....
 
Just to let you know, the specs are 6.5 pounds +/- 2 pounds (4.5 to 8.5 pounds). So hopefully they may make the pull better, but you might get it back with a notation the it meets specs.

Bob
 
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