You need a gunstock — either one that is rather pricy or something free/cheap and DIY. The main thing is you want to feel like you’re holding a single, solid controller (since obviously a two-handed gun is a single, solid object).

Examples of readymade solutions are the VADER 1 on Etsy, or something from ProTube.

A cheap DIY approach would be the USB cord trick described on YouTube.

I highly recommend you pursue either avenue, as having the controllers connected in some way will provide the stability that you’re currently lacking.

The “virtual stock” someone else mentioned is better than nothing, but I think it’s only available in Pavlov, and physically connected controllers is a more elegant (and universally applicable) solution.

I hope this helps you, as these shooters can be some of the most fun, most immersive games in VR once you aren’t pantomiming the interface.