BudsGunShop.com - Can I put a 15 round magazine in this VP9?

Yes, the low capacity versions aren't any different from the high capacity HK's, the only difference is the magazine. So the 15 round magazine will fit and function just fine. Hope this helps.

15rd magazines are in stock at the HK store, sign up for their deal alerts because they have sales all the time, when I got my conversion kit and my extra 17rd magazines they had 25% off and free shipping (when you spend $60) and it wasn't an advertised sale other then emailing people on their list.
https://hkparts.net/product/magazine-complete-15-round-9mm-hk-hk-vp9-hk-p30-p305.htm/

Yes, the VP9 prior to 2020 used to come standard with 15rd magazines, I bought mine in 2018 and got 15rd mags with mine, ice since bought the hk mag conversion kits to add +2 to my 15s but this pistol will run 10's, 15's, 17's or the 20's no problem

Marlin, yes Sir. Most manufacturers including H&K make firearm packages that have 10rd magazines so their pistols can also be sold in states that have magazine capacity restrictions. The pistols are exactly the same but just have 10rd mags included. The pistols will also accept any standard capacity magazines just fine. Cheers and stay safe!