If you're mangling, yes. If you are talented and graceful, no. While I wouldn't shoot them in competition, properly-pulled bullets don't shoot much, if any, different than the same bullet seated once.
Furthermore, I did an experiment last fall with LC M193 that a friend bought in the Big Obama Panic.
The factory stuff shot like 2 inches from a rifle that is pritnear a half-incher. So, I cycled through about 100 rounds, pulling them, soaking off the asphalt with acetone, then reseating to throat. Mutch better, under an inch for five.
Same deal with some 257 Bob factory ammo just a couple weeks ago. Pulling the bullets out a bit, then shoving them back in to throat, gave a 50 percent grouping improvement.