The 70T was/is a good rifle. I have owned 2 and both were very good. Both of mine shot longer/heavier bullets well.The stripper clip recess is for timed and rapid sections of certain NRA competitions where rapid reloading is required. Earlier models of Remington 700 and 40X rifles had similar cutouts but were discontinued in 1966.
Is your rifle stamped on the receiver with an 'MP' ?