Is it acceptable / ethical .......

[xjon]

So If I do not reload myself then how do I find the best rounds for my rifle if I don't try different loads and manufacturers?

I would do the same as you with factory loads. However to give each ammo a fair chance I would shoot 3 targets with 5 rounds each. Each ammo will have a cleaned and cooled barrel also.
Ive been to the range and shot a great group thinking Ive found my ammo only to come back and not replicate the grouping. Either stars lined up or lady luck shows.
Very time consuming but I enjoy it.
Also to eliminate the theory of trigger pulling the 5 rd group can help with that. Call your shots. Take note of every shot and ask yourself if it was good or pulled. To differentiate the holes in the paper you can either set up a camera system (spotting scope with iPhone) to record or color the tips of bullets with sharpie. You can also eliminate the worse 1 or 2 shots also.

 

[MJB]

Pick one bullet and just use that.....looks like the 180 is the best grouping but the 165 with the flyer is also in the money.

I'd go with the 165 for deer and just use that. Save the 180 for elk hunting.

Dirty barrel is a must 2-3 shot should do it