Agree! Not to derail the discussion and no disrespect to this dealer's forum, accuracy and tumbling can be addressed with the right load data as to Powder Weight and Overall length. When I started reloading years ago, I tried multiple options from FMJ, Painted, Copper Plated and Lead Cast. FMJ seems to be the cleanest option with a good choice of powder. But if you happen to shoot in a non-FMJ friendly range, (believe me, there are still few of them), you don't have a choice. Hot-loading is not suggested if you are shooting paper targets, as Power factor is not an issue. Accuracy can also be achieved with the right bullet diameter ( .355/.356/.357?? for 9mm only) as not all 9mm barrels are bored exactly the same size specially barrels nearing its maximum round count. And more important, the OVERALL Length. The shorter the loaded ammo length, the greater the chances of tumbling/keyholing. Wherein, if you max-out the longest Overall Length your gun accepts, tumbling/keyholing is no longer an issue (assuming no hot-loading). But if you want an easy to use no non-sense need to experiment with the right load recipe, FMJ is the easiest to use. Remember, FMJ is probably the best and readily available non-fancy projectile in the market. And regardless of the rifling profile of your barrel, FMJ is the choice for a general range use ammo.
Safe shooting fellow CGNutters!
