Different spring for lower power factor 9mm loads?

DIYguy · Apr 27, 2016

Just received my acceptance letter to the local outdoor gun club/range after the long waiting period. This club also hosts USPSA events which has my interest in participating in.
I'm wondering if anyone has experience with custom loads for lower power factors with their M&P9s?
Larger grain bullets, lower powder charge, lower FPS velocity = less recoil for speed shooting.
I know the different springs are available for the 1911s running lower PF but how about the M&P9s?
Any help?

McE · Apr 27, 2016

Wolff makes springs heavier and lighter than stock. You'll also need the Wolff guide rod to use them.

OKFC05 · Apr 27, 2016

Brownells has the ISMI springs in various weights that work on the stock guide M&P rod (ISMI is the OEM supplier).
I doubt you'll need to go lower than 15; the stock spring may work, depending on how "hard" your grip is.

Wee Hooker · Apr 27, 2016

OKFC05 said:
Brownells has the ISMI springs in various weights that work on the stock guide M&P rod (ISMI is the OEM supplier).
I doubt you'll need to go lower than 15; the stock spring may work, depending on how "hard" your grip is.

x2. I've purchased the ISMI springs (and new guide rod) for install into one of my M&P pro's. The 15# works fine with about anything that will cycle a slide. ( I mostly load 130 or 147gr over fast powders for low recoil.) To be honest, I have found the stock spring works just as well with any load that will make power factor and group accurately. In fact, I've found that anything requiring the 15# spring for reliability tends to shoot low and eratic so as to not be desirable anyway.

Personally, I would suggest you focus on your load THEN tweak teh gun if needed.

p.s. Any good competition forum (the Brian Enos community comes to mind) should have plenty of info on this.

DIYguy · Apr 28, 2016

Thanks Wee
I'm looking at different reloading systems and considering reloading my own. For now I keep collecting my different brass and giving them to my best friend to reload. Looking at different powder manufacturers, burn rates, bullet weights to see how close to the 130 PF we hit then see what I need to replace for spring to make it work. Was reading that the production division use the Minor PF scale for scoring so higher power doesn't get more points. Haven't shot competition yet, still in research mode.
Any info and advice is all helpful

Bkreutz · Apr 28, 2016

DIYguy said:
Thanks Wee
I'm looking at different reloading systems and considering reloading my own. For now I keep collecting my different brass and giving them to my best friend to reload. Looking at different powder manufacturers, burn rates, bullet weights to see how close to the 130 PF we hit then see what I need to replace for spring to make it work. Was reading that the production division use the Minor PF scale for scoring so higher power doesn't get more points. Haven't shot competition yet, still in research mode.
Any info and advice is all helpful

If you're shooting minor power factor (anything over 125) the stock recoil spring(17#) works the best. You don't need to fool around with springs until you load to sub minor or major, or if you modify the weight of the slide. I use a 13# in my 9 Major gun (172 PF) with a compensator. The compensator is so effective that the pistol won't cycle with minor PF ammo. My wife shoots my previous pistol (Core 9, Deltapoint, 136pf ammo) and I use a stock recoil spring in it.

OKFC05 · Apr 28, 2016

Was reading that the production division use the Minor PF scale for scoring so higher power doesn't get more points. Haven't shot competition yet, still in research mode.

In a 5" M&P9 Pro, I use 124gr FMJ Precision Delta over Titegroup making 130 PF (at 60 deg ambient) using the stock recoil spring. You can get into chrono trouble by trying to go too low on the PF, particularly if you work up your loads on a hot day and your powder is temp sensitive.

I put a 15# spring in a 4.25" barrel M&P for the benefit of beginners who are struggling to learn how to hold the gun; wimp grip + wimp ammo can give misfeeds.

As always, I suggest just gathering up your gear and some commercial 9mm and go shoot some matches so you can see how the game goes. Just be safe, have fun, and maybe learn something.

DIYguy · May 1, 2016

Guys...
Thank you, thank you, thank you!
I'm In MN and after shooting weekly through the Winter looking forward to the fun stuff out doors!

TacticalReload · May 1, 2016

Wee Hooker said:
To be honest, I have found the stock spring works just as well with any load that will make power factor and group accurately. In fact, I've found that anything requiring the 15# spring for reliability tends to shoot low and eratic so as to not be desirable anyway.

This.

I've found that the design of the pistol really benefits from a stronger spring for the sake of accuracy due to the prevention of unlocking too early. If you go much lighter, accuracy issues become exacerbated.

Different spring for lower power factor 9mm loads?

DIYguy

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McE

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OKFC05

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Wee Hooker

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DIYguy

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Bkreutz

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