HK
Will the +5 Extension work on a 17-round magazine?
The +5 fits fine, but it might only give you +4
Do you have replacement springs for thet VP9 20rd HK magazines?
Let's try this one to begin with and see if that's a good fit. HK changed the shape of the follower a year or two back, so if this one doesn't fit let me know and we'll get you the older (M&P-like) pattern.
TF/Wolff Spring for Sig 320 and HK VP9/P30 +5 (13 coil) - Taylorfreelance (taylorfreelancestore.com)
If you KNOW you have the older followers (from the days when the 9mm mags were 15 rounders), this is the older pattern:
Notes from Customers
NOTE: Other basepad brands may not fit (XTECH +5 basepads are too broad-shouldered)
NOTE: According to customers, this part does not work with Tyrant CNC mag extensions.
NOTE: According to customers, this part does not work with Tyrant CNC mag extensions.