how much does it cost?
The model 1890 Winchester was only chambered in .22 short,22long,22 long rifle,or 22WRF calibers which were all rimfire calibers.
No
yes
A couple of owners lifetimes.
No
Just the barrel?
Value of a 1980 Winchester rifle 22 short octagonal barrel?
fifteen hundred
In this model of Winchester rifle,there is no difference in value between the round or octagon barrel.
No
This is not a trivial thing. I would suggest that you go to http://www.krausebooks.com/category/firearms_knives and buy the Gun Digest book Assembly/Disassembly volume III on Rimfire Rifles. You will need a special spanner to remove the barrel nut. I too have this same question. The barrell of my Winchester Model 190 has begun to separate from the receiver. The firing pin does not strike the shell hard enough to fire the bullet. Has anyone discovered how to remove and replace the barell? http://www.swishercs.com/winchester/
The Winchester model 1894 rifle was never made with a vent rib barrel! the only Winchester made firearms with a vent rib barrel was Winchester shotguns.