I just got a Harris bipod for my rifle. I wasn't pleased with the rubber feet. Actually it wa the way the legs spun, keeping me from loading the bipod even minimally. I knew this was an issue before purchase, but didn't realize how bad. I had planned to replace the rubber feet with spikes or such. After looking at the cost of the commercially available options, I happened across a post on a forum somewhere, don't remember where that someone used cut down arrow field points. So, having a box of them sitting on the shelf, which I paid $6.99 for a dozen, I decided to do the same. I needed to remove the rubber feet, which involves driving out a roll pin. I came across a tool that one company makes specifically for this purpose. It is from Hawk Hill. Very inexpensive at $10, plus $3.50 shipping. You can use it with a hammer or with a vise. I used a vise as pressing a pin out is safer than pounding it out.
I drilled a pilot hole to keep it centered and then drilled a 5/16" hole in the rubber foot, which because of the flexible nature of the rubber produces a slightly undersized hole. 5/16" is the diameter of the field points I used. There are some that are smaller. After a test fit, I determined that I would not need to glue the cut down field points. I cut the entire shank off the field point with a dremel. Here is the before. Sorry I didn't take photos of the after.
I then pressed the point into the hole in the foot from the inside and reattached it to the leg of the bipod. Here is the finished result.
They are hardened steel, so won't dull easily from rock and concrete. And are inexpensive, readily available and easily replaceable. You can do the job with out the tool from Hawk Hill using a hammer and punch, which most will already have, making the cost only the field points.