Is there any way to adjust the tension on the side to side movement on the M82?  Mine seems a little to wobbly.

Most likely your bushings are worn out and need replaced. They’re relatively cheap and can be order through the Barrett parts store or by calling them.

For a quick fix, you can try tightening the bi-pod mounting bolts with an 11/16” socket. They’re torqued to 35ft-lbs.

Thanks!

What is your approximate serial number? Older bipod didn't have the nylon bushing. If you have the pull pin style attachment, new nylon bushings are in order.
Older bipod, you can get some flat nylon washers and install them between the studs the mounts go into the reciever and the bipod leg mounts.

I have an older rifle with a 1 of a kind reciever I got when I worked at Barrett. I put a piece of mouse pad between the bipod mount and reciever. Snugged up the bipod real nice.
I also used a mouse pad and hot glued it onto the upper as a cheek pad. Much cheaper than the factory Barrett cheek rest.

@skullbox

Check out Accu-Tac Bipods along with thier Barrett Rail that replaces the one that comes with your rifle.

I know James Yager is fighting words around here... but here is a video of James installing an Accu-Tac HD bipod on his Barrett.