Pick up a copy of Lyman's "AR Reloading Handbook", it'll square you away on cycling/pressure, etc. Powder selection is critical, as you don't want the pressure to peak too close to the gas port, as that overpressureing can cause all sorts of malfunctions, from failures to extract to broken extractors, broken lugs, etc. Just start on the low-end charge ranges for recommended AR powders to avoid pressure issues, and find what shoots most accurately. If your AR doesn't cycle with the recommended loads, there's something wrong with your AR's gassing that's bad enough that you're not going to get it "reliable" just by changing loads. That would show up in cold weather especially.
As to accuracy, if you just go by internet forums, every other Tactical Timmy online has an AR that shoots "Sub-MOA". Not only is that a difficult thing for the vast majority of shooters to consistently achieve, only a relatively small percentage of ARs are capable of it. Let alone across any given 10-round group. That's reality as I know it. If you get an off-the-shelf AR down to 1.5 MOA, you've got a great gun. MOA is definitely possible, but it takes a lot more to get there than with a lot of today's stock bolt guns, so you'll be paying for it.