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Discussion Starter #1
For the last couple of months I have been working on my MP9's trigger. I would shave a little off the sear then go to the range a few times to try it out. Do a little more adjusting and then head to the range, etc.



The trigger was very smooth, with an excellent reset, after polishing the internals but the overtravel is what bothered me and what I was trying to clean up. Finally tonight I got the trigger I was looking for, I think. My worry is I went to far. The sear releases the striker about 1/16 of an inch prior to the stops (trigger bar and trigger). No perceivable overtravel at all.



Will the trigger stay consistant and reliable or will the internals wear to the point that the sear is unable to release the striker?



Something else to add, I have not taken anything off the top of the sear, and know I can remove material from hear to lessen the engagement. How much can I remove and keep the gun safe for carry?



Thank you all for the advice.
 

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You should be fine, but live fire will tell the truth...



At least if you haven't touched the top of the sear, you will be able to at a later date if you start getting some failure to fires. One of the nicer quirks about the M&P trigger is that removing material from the top of the sear will advance the break point, and removing material from the front of the sear will retard it. Since you've only removed material from the front, you've got PLENTY of room to re-adjust it later if need be.



As far as how much you can remove from the top of the sear, you'll have to measure where you're at right now. Take a Sharpie and paint the striker where the sear touches it. Reassemble and dry fire a few times. Take the slide off and measure the amount of engagement surface you have - distance from the tip of the striker to where the marker has been scraped off. Most factory guns run .050" to .060", and a "safe" trigger job is around .030" (#'s according to the trigger job .pdf Dan hosts for us). For carry, you may want a bit more, but I have no experience there. In any case, a fair amount of material can be removed.



I'm sure Dan or David can chime in with the wear characteristics of the action, but from what I've seen, there really isn't that much to wear in/out that'll change the break point.



Hope that helps,

Dave
 

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Discussion Starter #3
Thank you Dave for the advice. After dry firing many times (150+ or -?) last night and this morning I have not had any failures but the realease point is now less than 1/16". The trigger feels great and I will have to go to the range again to test it for reliability.



I understand about marking up the striker to measure engagement with the sear. But then what is the best way to get an accurate measurement inorder to not go below .030"? Do I need special measuring equipment? I don't have calipers, yet.
 

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Discussion Starter #5
I have followed the instructions on the trigger job, it was extremely helpful. I think I will be okay with where I have it. I can't get to the range to confirm for a few more days (work) but I have yet to have a failure while dry firing and it feels really good. Again, thank you for the advice, encouragement, and link for the calipers.
 

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JLR,



I think the instructions mentions using a file on the top of the sear. I would be careful with that, you may take too much off too quickly or may make un-even cuts like others have done. I used a honing stone with a rough side and smooth side to polish. Get used to taking the gun apart and putting the gun back together to test it. Take the top of the sear down slowly and do test and go no further than .028" engagement like Dan says. Trigger may not work, then you need to take more off surface for over travel. When I put the roll pin back in, I had to adjust again.



S&W parts dept. does sell sears if you want to return to stock for some reason. I ordered one and they cost only $2 + $5 for shipping each so just FYI.



I did the trigger work and mag safety disconnect (my pistol had one) without making trips to the range. I just dry fired the nuts out of it with a snap cap till I felt safe and trigger worked consistenly 100%.



Went to range 2x this week and pistol shoots a lot more accurately, hardly none of that silly front site twitch sending my shots off.



Yes, first get get the micrometer or call around locally for one. Digital is easier for me to read. Let us know about your progress...



Have fun.
 

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Jeff 9mm M&P,



I have been unable to purchase a sear directly from Smith. Can you advise who I should speak with.



Thanks
 

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Sorry. I did so at their 1-800-331-0852 and just press the # for Parts Dept. Don't talk to customer service, they didn't have a clue when I talked to them about sears. I think I talked to Larry in parts. They are on company vacation till early January & not shipping. Large operation, expect slow shipping going this route. Took them 2 weeks or so to get a couple parts from them recently.



You can also order sears on-line through the MP-Store web site on this forum (go to the home page and click on MP Store, then Parts). Small operation and normally get part at home same week quickly but just a little more expensive. I know he got an order of sears in last weekend I received a sear going this route last week.



http://www.mp-store.com/product_info.php?c...b79bafe1a822993
 

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Jeff 9mm M&P said:
JLR,



I did the trigger work and mag safety disconnect (my pistol had one) without making trips to the range. I just dry fired the nuts out of it with a snap cap till I felt safe and trigger worked consistenly 100%.



Went to range 2x this week and pistol shoots a lot more accurately, hardly none of that silly front site twitch sending my shots off.


Not a technical or gunsmithing person.

Can you explain how this helps with accuracy? Also, how do you tell if you have a mag. safety disconnect?

Thanks!
 

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lefthandshooter said:
[quote name='Jeff 9mm M&P']JLR,



I did the trigger work and mag safety disconnect (my pistol had one) without making trips to the range. I just dry fired the nuts out of it with a snap cap till I felt safe and trigger worked consistenly 100%.



Went to range 2x this week and pistol shoots a lot more accurately, hardly none of that silly front site twitch sending my shots off.


Not a technical or gunsmithing person.

Can you explain how this helps with accuracy? Also, how do you tell if you have a mag. safety disconnect?

Thanks![/quote]



I just took my gun to the range. Chambered a bullet, dropped the mag and pulled the trigger. Mine went boom...big disappointment for me. I've got to get mine worked on.
 

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You should be fine.

Ive found that if anything; the overtravel will minutely increase over time, as the striker polishes the top of the sear.



Ive got my comp gun set up less than you and Ive got 15k on it thus far.
 

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Discussion Starter #12
Everything is running great. No failures after approx. 800 rounds. I am not touching it anymore.
 

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Discussion Starter #14
Jeff 9mm M&P said:
JLR,



Good work !



Have you noticed any improvement in your accuracy yet ? Does your front sight look more steady to you when the trigger breaks ?


I notice a big difference ( for the better) in the feel of the trigger take up, break, and lack of over travel. Accuracy has improved. Very easy to see that when I dry fire the sights remain rock solid (no twitch when it breaks). It is hard to explain, but the gun basically runs itself. Not much effort required to make good hits.
 
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