Man, sorry I didn't see this sooner...the Winchester model 50's aren't gas operated like todays semi-S/G's, it s patented as a "fixed-barrel, inertia firearm, (Filed in 1935, No. 2,144,951)" -> Designed by 'Carbine' Williams, the almighty beside Browning.
Anyhow, Don't shoot anything heavy or magnum if it's a featherweight..their aluminum receivers just can't handle it and hammer themselves apart. Especially if the timing is off (if you're ejecting shells more than 10 feet when you cycle, your timing's off...if it gets bad enough, you can get 20ft ejections that really piss off the person 5 benches over...)
If you're not sure of yours, check the serial number...earlier models were stamped with an "A" after the serial number, later ones actually had the word FEATHERWEIGHT stamped below the S/N
A properly tuned standard model 50 will hammer them out nice and purdy...though I personally don't plan to shoot anything over 1 1/4oz from the slug department...