I also prefer resting on a bag, rather than a bipod, for consistent results. In the field I invariably don't have to wait long before I find a weakness of a new bipod, which usually affects consistency/accuracy/varies point of impact. The rubber feet, spikes, loading/tension, angles, torque etc lead to too many unwelcome variables on different surfaces/positions. Using different rifles also presents a problem, as some shoot very differently to others.
Recently the Youtuber Scootch re-publicised a method for a cheap rifle bag, which I have used four times in the past week and find excellent with various air rifles. I found plastic BBs to be an excellent material for achieving consistent results with airguns. I try to rest the far end of a PCP's tank (always free floated, like the barrel) on the bag in order the stabilise the rifle the best ...... but always like to cup the rifle forestock with a hand in order to tame rifle movements ..... which I have found in 99% of cases does improve consistency/accuracy. A rifle bag can be placed on anything, ie a shooting bag, rock, branch, fence, sign post etc etc, yet permit tight groups. I am working on a small shooting bag to interact, with Velcro (to help with panning/absorption of energy/avoid torque etc), with rubber legs into shooting sticks, but the system is far from perfected.
https://www.youtube.com/watch?v=TTs0UyoRyEI I must admit to finding shooting sticks useful, made from sections of two carbon fly rod blanks that I never got around to building, though I usually leave them behind.