I have a marlin 782 bolt action in 22 win mag rimfire. I was wanting to change the barrel to the 17hmr. I cant find out if one of the barels made for this cal in another model such as 917 will interchange on the action. The bolt and mag appear to be the same, but don't have access to a 917 to check.

See if you can feed 17 HMR with the mag and barrel you have.

I strongly suspect that the barrel for the 917 would mount right up to your recever. It would not make a lot of business sense to use drasticly different receivers when both are intended to use the same size ammunition. As to the other suggestion, the 17HMR was designed to feed from the 22 magnum magazines and to use the 22 magnum bolt, and the part of the chamber behind the shoulder is the same, so feeding ammo through your existing rifle wouldn't really tell you anything.
But it WOULD surprise me if the barrel tenons for both your 782 and the 817 were different in any way.
I checked at the Numrich site, but as yet they did not have any 917 info on file. Was going to verify that the receivers were the same basic part numbers.

Thanks Vibe. I aggree with you, but I need to find out if the 17 cal will fit and if so where to get one. Marlin wont sell me one or say if they interchange. If I had both of them I could pull the barrels and check, but I dont. A gunsmith believes he could get one from marlin, but wasnt sure. Numrich was the first place I checked for parts and it didnt help for the 17 cal.

If all else fails you might try this way.
http://webpages.charter.net/news/

Keep in mind that this was posted in 2002

browser,

I relined/re-chambered a 782 to 17HMR about a year ago. It shoots excellent and as expected, nothing had to be changed but the barrel. Liners, drills (if needed) & reamers all available from Brownell's.

I would check Rimfire Central and Green Mountain rifle barrels