PM40 Recoil Assembly Question

[peashooter]

A search here did not turn up any definitive answer to this. HELP!

Kahr lists two different recoil assemblies for the PM40, a new style, and an old style. The description says that the old style outer spring has 13 coils, and the new style outer spring has 15 coils. I read on another thread here that the guide head is 1/2 inch diameter on the new style, and it is 3/8 inch diameter on the old style.
http://www.kahrtalk.com/showthread.php?t=4755&highlight=recoil+spring
Post #6 and 7. IDK if this is right or not.

The guide head on the recoil assembly in my gun is 1/2 inch in diameter, but some SFB clipped some turns off the outer spring before I got it, so I have no idea which spring was originally in the gun.

So which recoil assembly is the right one for my PM40?

[jocko]

if u slide has he what I call blunt nose version, u will take the old style recoil assembly. the front of the slide is very similar to glocks. the new style PM40 today and for the last few yeas has the beveled front slide which makes that the new style recoil assembly. which is the longer of the two recoil assemblyies. Neither will interchange.

Now I do think in the pat year all OM slides be they new style or old style now take the same outter recoil spring which is 13 coils, no longer 15.

The guide rod head today ALL are of the 1/2" SIZE so any recoil assembly u order today will have this size rod head. The one ur referring to is probably 4+ years outdated.

What I would recommend u do if u want to save some bucks and get the same results,it so go to the wolffs gunsprings site and just order the outter recoil spring in the 20.5# weight for ur PM40. It willb e listed in the PM9parts list. It willbe the correct spring for your PM40 no matter what kind of slide u have. The differene is the length of the recoil dual tube assembly and IMO u need not change that at all, just replace the outter spring and be done with it. (gunsprings.com)_ Kahrs webb site sometimes is confusing with the photos they show. They still show some of the PM series with the blunt noxe ersion. If u want to know the difference, just look at any of the cm 9 or 40 photos, as that is what the front of the new style slides would look like on ur PM40 if it is the new style, which I am betting it is..

[peashooter]

I was considering the Wolff spring. Why the 20.5 # spring instead of the standard 18 #?

[jocko]

imo U HAVE A 40 CAL, AND THE POWER difference of a 40 over a9mm to me is alot. I never understood why kahr used the same poundage on both calibers, but they do. buy um both and try um, u mingt not notice a bit of difference, as 2.5# is not alot either, It should last longer.
Will u feel less felt recoil??? Thats is up to the shooter,