Are stronger mag springs available for the P09?

[Warpspasm]

I just picked up a couple of +4 mag bases for my P09, and you can supposedly use them with the stock mag springs, but I would like to get a few stronger springs just in case. So for I haven't been able to f ind any.

[joedirt199]

CZ custom had 10% heavier springs for the full size mags. The original mag spring is pretty heavy already. I run 11-12 coil springs in my p09 with mag extensions and still get slide lock on empty. You will be fine with stock springs. A slightly lighter spring may allow an extra round and help with seating a loaded mag on a closed slide.

[Winkel]

You could disassemble and stretch your stock spring on one magazine and see how that does.

I've done it before. 

[Warpspasm]

Does that actually increase the spring power? I always figured the wire had to be more stout to increase power.

[joedirt199]

I wouldn't say stretching increases the power of the spring. Once you fully load a hand stratched mag spring, I bet it goes back to normal length when uncompressed. Pull it and see if it is still longer than stock after use. Stock mag springs are pretty long already and seem to handle extended mags fine.

[tomjbyron]

How about the springs from the Shield Arms +5 extensions? You can purchase the extra power springs for all three sized polymer CZ magazines.

https://shieldarms.com/cz-extension-replacement-spring

[Warpspasm]

The original spring seem to work fine. I took my P09 out today with the +4 mag extensions and put 150+ rounds through them without a hiccup. Thanks.

[Stuart]

The mag springs in the p09 are long and have a lot of force. They are fine with extended pads

[Wobbly]

Does that actually increase the spring power? I always figured the wire had to be more stout to increase power.

No, you've got many factors: wire dia, temper, free length, material type, etc. It's all about the force of the spring measured at a set distance, in this case the internal length of the mag, so say 7".

You must remember too that a larger wire size takes up more room, so you might run out of space and get into "coil binding". An increase of .005" doesn't sound like much, but spread over 20 coils you'd need 0.100" more free space to store that spring. That's the difference in holding 18 rounds versus 19.

[earlan357]

The +10% and Shield Arms springs have 15 coils compared to the OEM P09 spring with 13 coils.  The 13 coil spring is also standard on P09 mags with the OEM +2 extension and work great.  If you want to use 140mm extensions, the factory spring and follower work well too.  Trimming off a little of the rear leg of the follower will get most 140mm extensions to 22 rounds reloadable.  I tried the P09 Grams follower and spring.  It allowed for 23 but it was tight and the first rounds kept nosediving into the feedramp.  The center rib in the slide is of the P-10 is ramped and taller than a P07/09, so it compresses the rounds into the mag more when seated.  23 puts a ton of pressure on the bullet stack and mag catch.  When the slide tries to retract, the ramp puts additional pressure on the top rounds.  The slide velocity is slowed so much by the resistance that it often doesn't reach its full rearward stroke.  There's not enough time for the top round to rise and seat firmly against the feed lips and you end up with a nosedive jam into the feed ramp.

Now, I've heard you can use STI thin followers with 11-coil Grams springs to get 23 in there but I'm happy with 22.  23 isn't going to make a difference against the PCC/Open shooters and I still have more capacity than the Limited major guys.