"The best" of anything is a loaded question. Sorry for the pun. There isn't any one size fits all ammo for every gun. I don't compete, but I do handload. From my experience most competitive shooters eventually dive into reloading in the quest of finding the perfect load. I would say you will need to try as many different brands, grain weights and options as you can to find what your weapon likes and you can manage perfiently.

Originally Posted by Mikie

I have started shooting (today was my first time) a course at my local indoor range and would like to know what might be the best choice in ammo, as far as accuracy is concerned. I'm using my G17. I don't handload at this time.
The course of fire today was slow fire, timed fire, and rapid fire, at 30 feet, 60 rounds total, and the times were generous. I believe it may be NRA sanctioned. Thanks.

Tactworld45 has given good advice here. Everyone who puts rounds downrange on a regular basis has developed either a pet load or found something that feels good and feeds well in their firearm. You are at a decided disadvantage by not reloading but all is not lost. My suggestion is buy several boxes of different ammo and different bullet weights. Don't spend any money on hot or +P loads and no hollow points either. Just plain round nose or flat nose bullets. Your next best friend is going to be a notebook and a pencil. Several targets, some patches, and time. Start slow, always firing the same round, no mixing and start off using a bench rest. You want to find what feeds well, cycles well, ejects consistantly and what feels good to you. Finding the "perfect load" takes time and most of all repeating each shot as closely as possible to the last. You have to make sure you don't by accident put one brand at a disadvantage over another. Log your shots, log where each hits and logs your impressions. Later that evening you can go back and start reading and you may well be surprised at your findings. More often than not the round you thought in your head vs. the round that actually performed the best are quite different. Be SAFE.....Shoot WELL.....Have FUN

ATLANTA ARMS & AMMO

Atlanta Arms produces match grade ammunition and caters to pro/amateur shooters... They make several different versions of ammo, but have a 9mm 147gr 880fps round originally spec'd for Glock's Shooting Team... It is very popular for USPSA Production shooting... designed to make Minor...

I shoot Federal's American Eagle 147gr. in competition and have found it to be a reliable round. I like the heavier grain bullet for slightly softer recoil.