GBB spring upgrade question.

[Crunchmeister]

I've seen 150% recoil springs and 190% hammer springs for M9 series pistols.

Now, exactly what is it these springs do? I'm assuming the 150% spring is 50% more stiff thant he regular. Now how does this affect the recoil of the gun itself? And the 190% hammer spring increases the strength of the hammer by an extra 90%. What effect does this have on the performance of the pistol, other than making the hammer stiffer? Does the extra power allow more gas to escape per shot? How does it affect the reliability of the blowback action, since the slide now has to cock back a hammer with more tension on it.

And if I were to order these springs (already have them priced out at WGC), is there anything else that I need to do to the gun for it to operate properly with these new stronger springs? I've read of mods where valves and such are changed as well as the springs, etc. I'm a noob, so have no idea. I know that often certain mods will require other mods in order for them to operate properly. I just don't want to order these springs, install them, then learn afterwards that my gun can't supply enough gas flow with its stock internals to operate the gun.

Hope you gurus can help me out here and forgive what may appear to be a bit of a noobish question. But we all have to learn sometime, right?

[ILLusion]

The stronger the recoil spring, the faster it will return the slide to battery, but it will also consume more gas.

Ultimately, it makes the recoil much more crisp, and if you want your gun to feel more real, go for the heaviest springs you can find (and that your propellant can handle.)


Stronger hammer springs are for making your gas output more consistent. The more powerful your propellant is, the stronger the hammer spring you'll require to crack the valve open. High pressured propellants can be strong enough may cause your valve to not release any gas when struck by a stock recoil spring. Even propane/green gas on a warm summer day can cause this. But again, the stronger the spring, the more gas is consumed during the blowback process. I wouldn't go more than 150% for a hammer spring if you're using propane.

There shouldn't be any issues with swapping the springs on an otherwise stock gun.

[Scooby Steve]

A stronger recoil spring is needed when you've installed a metal slide on a GBB because of the extra weight of the slide. Some recoil springs come with a stiffer hammer spring. I'd suggest also installing a high-output valve in your mags and a metal valve in the nozzle that's inside the slide.

In researching hammer spring installs I learned that they can be extremely difficult and shouldn't be attempted by a novice. Plus, some have said that a new hammer spring isn't all that necessary. For that reason I've left the stock ones in mine. If I were to get hammer springs installed I'd contact a gun doc and arrange for him to do it as I've seen a lot of posts where someone couldn't get their hammer assembly back together.

[ILLusion]

A high output valve isn't required, nor is it necessary. Its only purpose is to increase velocity. If you're after that, then yes, I'd recommend the high output valve. That alone is your greatest source of increased power (besides going up in propellant.)

There are only certain guns that have difficulty getting hammer springs in. Pretty much all 1911, 2011 and similar clones are easy-peasy to get the hammer spring in. I'm not sure about the M9, though. Glocks are generally the hardest.

[Scooby Steve]

Yeah, I was researching installing a hammer spring in my TM Glock 17 and what I read scared me. Maybe I'll try putting a hammer spring in my Marui 5.1.

[Crunchmeister]

Thanks for the info guys. I was just a little concerned since from just the reading I've done on this board and other sites in the past week, I know that with an AEG, an upgrade as simple as a slightly stiffer spring can also require a swap of bushings, gears, etc (depending on the gearbox version) in order to not cause any damage to the gun's internals. I just wanted to make sure this wasn't also the case for a GBB gun/

Originally Posted by Scooby Steve

A stronger recoil spring is needed when you've installed a metal slide on a GBB because of the extra weight of the slide.

I've got the KJW M9 Full Metal version, so it came with a metal slide already. I can't really say what the slide action is like under normal conditions. After I got it, I removed the stock grips to install some Hogue grips, and the trigger bar spring flew out and went down the drain of the kitchen sink (metal note: NEVER work on the kitchen counter). In order to be able to shoot the gun (without holding it either upside down or on the side gangsta-style), I've had to wedge a toothpick under the grip plate to press the trigger bar up. This has a bit of an effect on the slide action. But I have a King Arms M9 respring kit (I believe they're standard tension springs) on the way from WGC and it should be here this week. Then I'll see how it works out. I am liking the idea of the stiffer recoil spring though. I like the gun to have more of a kick, even if it's at the expense of gas. I mean, I should still be able to have enough gas to handle the 25 shots in the mag even with a stiffer spring.