The stock spring is the same for both at 17 pounds. I have run up to 22 pounds without issue in my 17 but I stick to 20 now.
Tdc
This only applies to the Gen 3's and earlier models. In the Gen 4's, the recoils springs are different 0-1-4 (G22) vs 0-2-4 (G17). I changed the RSA in my Gen 4 to a G17 spring for the 40-9 conversion.
Are they a different weight? Even so I suspect that either will work fine.
Tdc
No hiccups filling my .40 glock mags with 9mm.




























