I'll echo the above and say Simms 100%
I've marched around for a week straight in a pair of G3 waders with these boots a few times and they were great.
RCBS FL bushing die set (no bushing) with micrometer seater. Sizer has never been used and the seater maybe loaded 30 rounds so basically brand new.
P/N 13608
$150 tyd Paypal ff or venmo.
If you dont plan on shooting heavy for caliber bullets and the 1-10 twist works then go for it. I'd say just get it if it's a great deal and use the action. Or shoot the 243 barrel its still a great cartridge don't let the 6CM and all these new "updated" overshadow it. Depends on your objective...
Technically it already is a 6mm. Depending on what 6mm cartridge you want to shoot you may or may not need a new bolt face. I'd think about the bullet you want to oush since those older t3 243s have a slower twist.