To adapt your Western Auto 220 to clip-fed, all you need to do is mill a stripper clip slot into the rear receiver bridge.
Mill it to fit Springfield, Mauser, or whatever style stripper clip you want. It'll probably interfere with the rear scope base mount, but you can't charge with clips if you've got a scope moutned top n center anyway.
Now after that bit of kidding around...I'll assume you're talking about a detachable magazine conversion.
Like RJay said...practical, probably not. If you are a good machinist you could adapt a detachable magazine floorplate assembly to your rifle but it won't be an easy project even with a well-equipped shop. All said and done, it would be cheaper to use it as trading material for a rifle already set up with a detachable mag...or one that has the aftermarket parts available (like the Remington 700, Savage 110-family, Ruger 77 etc). Or just plain keep your 220 as-is and add another rifle to your stable.
Is the
Ruger 77 Scout Rifle kinda what you're looking for?