Guide rod diameter

[delleetodd]

Can anyone give me the guide rod diameter of the CW9/P9?

CW45/P45?

Glock 19 gen 3 or older?

Thanks! I want to fit my PM45 with a single recoil spring just to experiment with different spring rates. If I can find a rod the correct diameter I can always cut it down to fit. I will share what I figure out in this thread. Guide rod nut is 0.319” on my PM45. I’m open to suggestions.

[jokester945]

I’m sure it’s do-able, and I’m sure you know that for the P9 (don’t know about the CW9) the spring is super strong. I think it needs to be for feeding and extracting. Even then the first rounds in the mags are already offset to assist.

Are you doing this because the slide is so tight?


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[delleetodd]

I’m doing it because I feel the PM45 recoil springs are a bit off. I sometimes feel the slide bottom hard while shooting. My main concern is the round nut on the end of the guide rod can catch on the end of the slide if the rod isn’t aligned perfectly. I usually notice it after I get home from the range. After I clean and reassemble, it lines up fine. I haven’t had a malfunction from it but it concerns me. I bought another guide rod assembly and it does the same thing. Kahr told me that it is kind of normal with that gun.

When I pull the slide back I notice the small inner rod pokes out first and the large outer rod is still recessed slightly. As I keep pulling back the slide the large outer rod shows itself. When just the small rod is protruding through the much larger slide hole it give room for the guide rod to move off center.

My CM9 works the opposite way. The large diameter rod pops out first followed by the small inner rod. I feel this is how it should work and there is no way to become misaligned. I ordered a 20.5 pound spring set from Wolff for a PM9 to play with or mix and match with stick springs. Also playing with the idea of using a single spring but I need to know if the guide rod from a P or CW series is the same diameter as the dual recoil spring assembly.

[delleetodd]

If the PM45 inner spring was a little stiffer it would work better. I also think the outer recoil spring has the potential to pop out of the slide hole when just the small guide ride is hanging out. I really like the gun of I wouldn’t go through the trouble of trying the make it right.

[gb6491]

Can anyone give me the guide rod diameter of the CW9/P9?

CW45/P45?

Glock 19 gen 3 or older?

Thanks! I want to fit my PM45 with a single recoil spring just to experiment with different spring rates. If I can find a rod the correct diameter I can always cut it down to fit. I will share what I figure out in this thread. Guide rod nut is 0.319” on my PM45. I’m open to suggestions.
Wear and tear has made precise readings difficult (nothing is quite round or smooth), so this is what I've got:
CW9 guide rod: 7.56mm +/- .02mm
CW45 guide rod: 7.65mm +/- .02mm
The CW45 guide rod will fit in the CW9 slide. Both slides have a hole close to 7.9mm in diameter.

Glock 19 Gen3 guide rod: the little cap on the end is not round on my gun, let's say it's just under 7.09mm to just over 7.0mm. The hole in the slide is around 7.09mm

Regards,
Greg

[delleetodd]

Thanks Greg. Looks like they will fit fine. I will order a P45 guide rod and some springs from Wolff. They have 18 to 23 pounds. Will have to cut the guide rod and springs to fit bit that isn’t a big deal. Guide rod is under $4.

[delleetodd]

Ok so I made a little fixture to hold the stock recoil spring assembly of the PM45 while I measure it with a digital force gage. The stock guide rod sticks out about 1.6” when the slide is all the way back so I set up the fixture to stroke the RSA about 1.6”.

When I put the RSA through it’s stroke I notice that the large outer spring goes into coil bind about 3/4 or the way through. The small inner spring does the work the rest of the way. I still think the small inner spring could be stiffer. Just enough to force the outer guide Out of the slide first.

I have 2 RSAs
Original one exerts about 9 pounds at rest and 18 pounds at full slide compression.
2nd RSA exerts about 9.5 pounds at rest and 18.5 pounds compressed.

Im waiting for a Wolff 20 pound PM9 spring set to show up. I also ordered a P45 guide rod and multiple Wolff springs to try out. I can put the springs and guide rods in my fixture to test and get the spring length correct before I head to th range.

[delleetodd]

A little more thought into the outer spring going into coil bind. The springs both are compressing together but the larger spring binds first. At this point the spring rate goes up when the inner spring takes over. The dual springs are a more progressive setup than a single spring. There is obvious pros and cons to the dual springs vs single springs. I assume that a single spring RSA that ends at 18 pounds will start higher than 9 pounds. We will see.

[delleetodd]

Please move to PM forum and it would be sweet if the mods would let me post pictures.

[Bawanna]

Done.

You can post pictures now via places like image post or tiny pic or one of them.
After you hit 30 post you can post direct.

[DJK11]

So what’s the consensus on the single spring?

[delleetodd]

Single spring did not work. Couldn’t fit enough spring on a guide rod that would provide enough force for reliable feeding. I guess that is why short guns have dual recoil springs. I had problems with the guide rod being constantly out of alignment. The nut would catch on the end of the slide as it closed out of battery. On the second time back to Kahr they replaced my slide and things looked promising at the range until the cocking cam jammed against the striker safety plunger. Third time back to Kahr they decided to give me a new gun. I asked for a P9 which hopefully will be a much better carry gun. I have a CM9 my wife carries that has been 100% reliable. I really like Kahr but right now I have a bad taste in my mouth from dealing with customer service for the last 4-5 months. If the P9 is reliable I will probably carry it a lot. Right now I carry one of two Glock 26s I own or a Glock 19.