Lighter recoil spring for M&P9

[Gary H.]

I've searched the messages but my search-fu is lacking. I'm developing a load for the wife to shoot regularly and for me to shoot IDPA with. If I get my 147s down to about 130 power factor or 885 ft/second, the slide doesn't lock back consistently. If I kick that up to 900 FPS and all is fine. I'm just trying to loose a little more recoil and have room on the PF floor. I'm guessing the recoil spring is a little strong. I've had the same issues when I loaded 115s or 124s and have to load the 115s right up to the maximum recommended load recipes to get it to lock back consistently. I see that there is an issue with them not wanting to stay locked up with the lighter springs like the guys run in the glocks. You guys have any recommendations? Someone also told me that the new guide rods on the M&Ps have a removable end allowing one to change springs. Is this true and any idea of where I can pick one up or do I just need to get the stainless guide rod from SSS? I've got this thing about as tricked out as one can get it and it has all the Apex parts and springs. Anyone want to recommend spring weights and do I need to trim a few coils off the striker spring to make lighter springs work?

[sdm74]

Your not possibly thumbing the slide occasionally are you? I run 147 with a 130 power factor and my slide locks back everytime.

BTW you had 400th post in s&w...lol

[TAP]

My M&P9 runs perfectly with 116 PF loads and the stock recoil spring. I would buy another stock recoil spring and try that out before you start experimenting.

I have run a SSS stainless uncaptured rod with a 13# spring. It works fine but the slide is a little to easy to come out of battery IMO.

[Darrin]

I shoot 147's at about 130PF with a 13# recoil spring. I have run it that way for a few years and just recently put in a reduced power striker spring with no problems. But I do use federal primers.

[mdschappell]

I had been using a 13# spring, but didn't like the way it locked up.... it seemed a little loose and "sloppy". It never malfunctioned and I never had any light strike issues with it, but I like the way the stock weight spring locks up better.

[E K]

Your not possibly thumbing the slide occasionally are you? I run 147 with a 130 power factor and my slide locks back everytime.

BTW you had 400th post in s&w...lol

Good point. I shoot minor loads with stock spring and have never had a single issue.

[Gary H.]

definately not thumbing the slide. I had that problem with a 1911 and know the scenario. It even does it when I completely clear my hand from that area of the gun. Maybe I just have a strong spring???

Does anyone know of a new guide rod with a hex head on it to allow removal of the spring? I know sss sells a stainless guide rod. Maybe I'll go that way with that and get a 13# to try & 15# in case of issues.

[sdm74]

I have read on here that with 13# doesn't even keep slide shut firmly. What is stock #? Is there a # in between factory and 13#

[ebg3]

I have read on here that with 13# doesn't even keep slide shut firmly. What is stock #? Is there a # in between factory and 13#

Had the problem of the slide not locking back when I was shooting a M&P...In my case I was riding the slide stop. Using a SSS guide rod and a new 13lb spring worked fine for me until the spring started to weaken, then I started seeing some malfs. Went to a 15lb spring and all was well. I think stock is 16lbs?

Edited March 25, 2011 by ebg3

[Gary H.]

Had the problem of the slide not locking back when I was shooting a M&P...In my case I was riding the slide stop. Using a SSS guide rod and a new 13lb spring worked fine for me until the spring started to weaken, then I started seeing some malfs. Went to a 15lb spring and all was well. I think stock is 16lbs?

The difference could be as I explained in my original post. The slide locks back on the stronger loads. While shooting Winchester White Box, I have not had a single issue. If I load around 140 power factor, I never have a problem. It's only with light loads! Some of my shooting buddies are shooting 2.9 TightGroup and 147 BBI cast lead making power factor. I have to load the same load at 3.2g TG for my slide to lock back.

Is there something that could be done to the M&P's to help them go into battery and stay locked up with the lighter recoil spring? Other than say lightening the slide anyhow.

[LikesToShoot]

Had the problem of the slide not locking back when I was shooting a M&P...In my case I was riding the slide stop. Using a SSS guide rod and a new 13lb spring worked fine for me until the spring started to weaken, then I started seeing some malfs. Went to a 15lb spring and all was well. I think stock is 16lbs?

The difference could be as I explained in my original post. The slide locks back on the stronger loads. While shooting Winchester White Box, I have not had a single issue. If I load around 140 power factor, I never have a problem. It's only with light loads! Some of my shooting buddies are shooting 2.9 TightGroup and 147 BBI cast lead making power factor. I have to load the same load at 3.2g TG for my slide to lock back.

Is there something that could be done to the M&P's to help them go into battery and stay locked up with the lighter recoil spring? Other than say lightening the slide anyhow.

Gary,

I think you already know the answer.

Lighten the slide or increase the loads. My FS has the same problem with bunny fart loads and the #13 recoil spring.

2.9TG and 147 BBI is cutting it a little too close, IMHO.

I sure wouldn't want to be DQ'd for that small of an advantage.

I had light primer strike at a major match that were blown off as bad primers, only to find out that it was firing out of battery because of a #13 recoil spring.

#13 spring now in the trash.

If you get used to the 130PF+ range you'll never have to worry about a weak chrony.

I go with 3.3TG ,147gr LFP and a 15# it always goes BANG!

JMHO.

Steve

[Mustang684]

Had the problem of the slide not locking back when I was shooting a M&P...In my case I was riding the slide stop. Using a SSS guide rod and a new 13lb spring worked fine for me until the spring started to weaken, then I started seeing some malfs. Went to a 15lb spring and all was well. I think stock is 16lbs?

The difference could be as I explained in my original post. The slide locks back on the stronger loads. While shooting Winchester White Box, I have not had a single issue. If I load around 140 power factor, I never have a problem. It's only with light loads! Some of my shooting buddies are shooting 2.9 TightGroup and 147 BBI cast lead making power factor. I have to load the same load at 3.2g TG for my slide to lock back.

Is there something that could be done to the M&P's to help them go into battery and stay locked up with the lighter recoil spring? Other than say lightening the slide anyhow.

Gary,

I think you already know the answer.

Lighten the slide or increase the loads. My FS has the same problem with bunny fart loads and the #13 recoil spring.

2.9TG and 147 BBI is cutting it a little too close, IMHO.

I sure wouldn't want to be DQ'd for that small of an advantage.

I had light primer strike at a major match that were blown off as bad primers, only to find out that it was firing out of battery because of a #13 recoil spring.

#13 spring now in the trash.

If you get used to the 130PF+ range you'll never have to worry about a weak chrony.

I go with 3.3TG ,147gr LFP and a 15# it always goes BANG!

JMHO.

Steve

Not sure on the regular M&P, but the new Pros have a guiderod with hexnut on the end. So far, the factory spring cycles with Atlanta Arms, Rem UMC, and WWB without slidelock issues.

[Gary H.]

Not sure on the regular M&P, but the new Pros have a guiderod with hexnut on the end. So far, the factory spring cycles with Atlanta Arms, Rem UMC, and WWB without slidelock issues.

That's where the info came from then. I guess you can order the part straight from S&W or is there another source that might have it.

I know I'm pushing the limit on the PF, but I was just trying to put together a load the wife likes more than anything. AS I said, 3.1 runs in her M&P fine but it runs right at 132 PF on my scale through her 5".

[sdm74]

Not sure on the regular M&P, but the new Pros have a guiderod with hexnut on the end. So far, the factory spring cycles with Atlanta Arms, Rem UMC, and WWB without slidelock issues.

That's where the info came from then. I guess you can order the part straight from S&W or is there another source that might have it.

I know I'm pushing the limit on the PF, but I was just trying to put together a load the wife likes more than anything. AS I said, 3.1 runs in her M&P fine but it runs right at 132 PF on my scale through her 5".

Iss that with tite group? I have to load 3.3 to 3.4 to get 130 out of my 5"

[Gary H.]

Yep, 2 of my buddies run the 2.9g titegroup/147g BBI, one in a Glock and one in an M&P Pro 5" and both of them are just barely making power factor, but they are making it. One of them does quite a bit of traveling shooting large matches and hasn't had a problem. I haven't chronoed mine at 2.9 because it won't run properly (slide won't lock).

[sdm74]

O ok the bbi I am using mg cmj

[MemphisMechanic]

I had the same issue. With anything other than a death-grip, my 9L would only lock open about 50% of the time if shot one-handed at 130PF with a BBI 130gr.

I rock a 13lb ISMSI spring for a Glock 34 in my M&P now. Pops right on the factory guide rod, and runs like a champ. I had it lying around, compared it to the stock M&P spring... and figured - why not?

Good balance between the factory spring, and a too-light-to-stay-in-battery 11 pound M&P Spring.

Edited March 31, 2011 by MemphisMechanic

[Gary H.]

Got my springs and guide rod from SSS today. I put the 13 in and it locked up tight. I thought I'd try the 11 and it locked, but was loose and came out of battery when I put in a full mag. I pulled the striker and cut the spring. Wasn't sure how to do this so I started slow. Figuring the first coil was flat, I wouldn't call it a coil but a rest area, I went down straight from the end of the spring 1 coil and cut it there, and bent it flat. I would guess I shortened it by a coil and a half. Inserted the full mag and it stayed locked up. Pulled the mag and shook it and it stayed. Ran a full mag through it by pulling the slide back and releasing it to let the springs close it and it was locking up. Couldn't shake it loose, so I think I'm going to try this thing out tomorrow. If not, definately on Saturday at the Steel match at the club.

[LikesToShoot]

Got my springs and guide rod from SSS today. I put the 13 in and it locked up tight. I thought I'd try the 11 and it locked, but was loose and came out of battery when I put in a full mag. I pulled the striker and cut the spring. Wasn't sure how to do this so I started slow. Figuring the first coil was flat, I wouldn't call it a coil but a rest area, I went down straight from the end of the spring 1 coil and cut it there, and bent it flat. I would guess I shortened it by a coil and a half. Inserted the full mag and it stayed locked up. Pulled the mag and shook it and it stayed. Ran a full mag through it by pulling the slide back and releasing it to let the springs close it and it was locking up. Couldn't shake it loose, so I think I'm going to try this thing out tomorrow. If not, definately on Saturday at the Steel match at the club.

Looking forward to getting your range report.

I wouldn't be messing with cutting the striker spring. From everything I read, lightening the striker spring doesn't reduce trigger pull on the M&P.

[Kevin G.]

Sounds like you have yours set up like I've been running mine. However, I bought a Glock 34 stainless captured guide rod, a 13 pound and a 15 pound ISMI spring. I run the 13 on the glock captured rod with two coils cut off the Apex striker spring. Before cutting the striker spring lockup was questionable. Much better now. I load CCI and TULA primers without any issues yet. I keep the 15pound spring installed on the factory guide rod in my range bag JIC it ever starts giving me fits while I'm shooting. The factory spring stays in the tool chest at home.

Good luck with getting it tuned and playing nice.

[Gary H.]

Looking forward to getting your range report.

I wouldn't be messing with cutting the striker spring. From everything I read, lightening the striker spring doesn't reduce trigger pull on the M&P.

The reason had nothing to do with lightening the trigger pull. Thank goodness. My trigger is awesome right now. I had a couple of good 2011 guys (gunsmiths) shoot it last week during range practice and the first words out of their mouth were,,,,WOW! Personally, I don't want it any lighter. The problem with leaving the striker spring at factory or SSS strength is that it fights against the recoil spring keeping the gun locked up. I ordered an extra striker spring from SSS just in case I didn't do it right and am going to keep it in the range bag along with the other recoil springs if I start having problems. I'm going to head to the range today so I can take my time and check lockup very thoroughly before I try running it all out. If these mods keep making me like this M&P just a little more, I'm going to order another as a backup and this on is going to go into a full blown Open Major build! The way it is now, I can still run it in ESP IDPA. With the new sights and trigger, I'm much more accurate with it, now I just gotta get my speed up.

Kevin, all my reloads now have Winchester primers in them. Hopefully I'll be ok with them, if not, I'll have to stop and pick up some Feds or CCI. One of my friends that I mentioned in another thread is using an 11 lb. spring in his and not cutting the striker. So far, he's had no problems, but he's pretty much shooting bunny farts!

DMAC, we need those pictures

Edited April 2, 2011 by Gary H.

[Gary H.]

`Ran 300 rounds through it today. It will definately lock up and I didn't have any problems running the 11 lb. spring. I did have an issue not goingto slide lock on lighter loads for some reason. I started digging into that a little more with an empty mag and when it does it, it doesn't stay back when I rack the slide full back even. When I push the slide stop up, it will work again. I'll have to pull that apart tonight to see whats up. I may just run the 22/45 tomorrow in steel. I really need to get my speed up and the only thing that will do that is trigger/sight time.

[Severian]

I guess every M&P is different. I'm using 147 gr over 3.1gr TG with an 11lb recoil spring. No problems at all so far. Maybe 500 rds through it. Oh, and I'm using a ISMI captured guide rod that fits my Glock 34. Runs flawlessly.

Gary: I didn't hav any problems today. I even ran about 40 rds of 2.9 TG through the gun with no FTRB problems at all. I know that's a little light, but perhaps it's my steel captured guide rod. Or maybe it's my awesome mental power. I can will these rds to do just what I want them to do. Pretty amazing, huh?

- Jeff

Edited April 2, 2011 by Severian

[Gary H.]

I hope you don't Jeff, the way that slide rattles when you shake it made me vary leary! I'd definately cut your striker spring a little. I've got a spare in my range bag if you mess it up. I'd hate to see that thing go kaboom on you.

I can't belive you and Mark get by running a load that close to PF without problems at matches. TG must be vary stable! That or you got that Yoda thing going with the chrono

[Severian]

I hope you don't Jeff, the way that slide rattles when you shake it made me vary leary! I'd definately cut your striker spring a little. I've got a spare in my range bag if you mess it up. I'd hate to see that thing go kaboom on you.

I can't belive you and Mark get by running a load that close to PF without problems at matches. TG must be vary stable! That or you got that Yoda thing going with the chrono

Okay, let's say I take a few coils off my striker spring. I looked at it after I shot. The spring looks like it is "fitted" on both ends. The rear looks more "fitted" than the forward end. So if I take off a few coils, do I have to worry about the fitting? Is there anything special to do after I cut them off? Like file the end of the cut spring or something else?

Thanks for the help!

Jeff