Any standard ammo should work. Keep in mind the Model 100 is a fairly delicate action and is considered "obsolete". Not easy to work on and parts are not exactly easily avaiable. Probably time to start thinking about a new rifle.
In life, strive to take the high road....It offers a better field of fire.
"Robo is right" Fuzzball
I have gad no issues with the rifle-gas system has just been cleaned after 30 years of crude in there. Took it to the range, no problems. Firing pin was changed and as far as getting another rifle, my dad had it since 1961 whats another 50 years on my winchester.