i have a winchester model 250 and a friend gave me a bushnell 3x-7x custom 22 scope. is there any way to mate the two?

Welcome to the forum Jeep. Rules are simple, be nice and join in.

If it's a one inch diameter tube scope you can get a set of rings from Walmart or most sporting goods stores for the grooved receiver of your Win 250. If you look on the top of the receiver of your rifle you'll find two grooves that run parallel to the barrel. There are scope rings made to fasten to those. Ask for scope rings for 22 rifles that have grooved receivers. I paid six bucks for the last set I bought from Walmart.

the tube diameter is about 13/16 and it has the same grooves on the bottomof the scope as the rifle does.

The scope comes with the rings built in. These were designed as 22 scopes. It should just fasten on to the grooved reciever.