I have a FW barreled action in 243,with g&h side mount and rings, no bottom metal ,magazine, folloer or spring, since no collector value and I have a standard box and follower thought I would rebarrel in 6.5 swede. Do you know of any problems or reasons The swede wouldn't work?

Not a big deal . However you have to decide which standard you want since American makers have screwed up the system !
Assuming you want accuracy ,pick either the European 6.5x55SE and stick with European cases, OR pick USA standards and stick with USA cases. Make sure your dies match the chamber.
If you're handloading you should be able to get 2750 with a 140 gr with a powder like 4350, and be withing reasonable [original] pressures.
Then you can have fun and fill your freezer .As Finn Aagaard said the 6.5x55 is the perfect deer rifle !

Yep, the 6.5 swede is " currently" my favorate I've made lots of large deer very dead very quick. I had an experience with brass in my 700 classic of not extracting I believe I oversized causing my peoblem and you my have solved my problem , lapua brass in the remington factory chamber.