You didn't indicate the diameter of the bullets that you are using but it sounds like they are probably .311"-.312"? The 7.65x21 bullet should be .308"
If your barrel is worn then you are probably OK with shooting these but you might experience failure to feed issues with some brands of cases if they are thick enough that a .311 bullet will bulge the neck to the point that the reload won't fully enter the chamber.
Graf's carry PRVI 85 grain .3065 7.65 Luger bullets for $19/100 ct. (+tax & shipping) in case you're interested. They work fine in my Lugers. My apology if you already know this info.
-Bob
https://www.grafs.com/retail/catalog...roductId/29125