So, for those of you that want more grip to your HK VP9, here is a solution. It was designed for a TPU material. If you print it in PLA it's probably not going to work. The nubbins were styled after the HK USP. But these are even more aggressive.
I printed in a Polymaker 95HF and it works good. Wall thickness of 2 and 12% infill is a good starting point to get your desired squishyness. I did a few in Polymaker 90, and that didn't print as well. Note: I have a Bowden set up. But the 90 was easier to tune in the desired squishyness.
There is even a fun quote on the back.
The support is meant to be cut away and you can put the seam on the support to make it pretty.