I have been reading the Fly Rule Book to see whether or not a rimfire can use a bi-pod as its front support.
The Light Gun can use a bi-pod because the rules mention that the weight of the bi-pod must be included in the weight of the rifle, which must meet the 17 pound limit.
I concluded that if a Light Gun can use a bi-pod and the rules don't specifically say that a bi-pod can't be use for a rimfire (or for that matter a Heavy Gun) then it must be ok to use a bi-pod on a rimfire rifle.
Welcome to the forum again mate, can I please ask you to use your real name and add a photo on here rather than Panda Shooter, its one of the simple forum rules to keep it all positive and so everyone knows who they are talking to.
As Fred pointed out rule 3.2.1 specifies that Light Gun and Rimfire can have a bipod attached, but must be under the 17lb including the bi-pod, Heavy Gun can not be shot from a Bi-pod. As most rimfires are less that 13lb anyway.... you should have no trouble attaching a bi-pod to anything you may have.