In 1910, W.W Greener wrote (in The Gun and its Development): In no country are better sportsmen to be found than in the United States of America, nor does any country possess keener buyers or better men of business, yet is so much of the worthless of the (mass production) gun-factories offered for sale. The Boers are a race of sportsmen, but it is no use to offer them rubbish at any price, and the author can hardly believe that the astute American will sacrifice everything to cheapness.
I don't mean to be rude, but the idea of buying a new rifle and then 'upgrading' it by fiddling with it and possibly replacing parts, strikes me as bizarre. Nor does it say much for the quality of product that Winchester is selling.
Apparently, there are so many after-market add-ons to a Harley Davidson motorcycle that you can build yourself a new engine without a single part from the factory. In which case (if you are inclined to do so)... why are you buying that motorcycle - or rifle - in the first place?
As I say, I have no wish to be unpleasant, but if you are spending your money on something that needs work on it to operate as you want it to, perhaps you have bought the wrong product to begin with. No European would buy a new rifle with the intent of throwing half of it away and rebuilding it.