If you can’t shoot a gun well enough to take advantage of precision zeroing, and yet you want your gun precision zeroed, have someone else who is competent do it for you.
Using some general internet experience with ammo and sight picture and distance to develop your own gun’s precision aiming, considering all the variables involved, just adds complexity to the process.
If conditions at your indoor range are so bad for this exercise, find another place to shoot, even outdoors with your own table and rest.
But you will never develop or confirm your zero, for your gun, with your choice of sights and ammo and zeroing distance, without experimentally shooting your gun precisely.
Recognizing this, the factory does not offer you meaningless guidelines they can’t guarantee in a mass produced gun they don’t test and adjust for accuracy.
Buy a custom gun with custom ammo sighted in and sample targets with an accuracy guarantee, then you will have paid someone to do this work for you. But if you are not a good shot, it won’t be worth the money.
Really, just hang a target in good light at the distance you want to have your zero with some decent target ammo you like, find a way to rest your forearms and hands (not the gun) on something solid, and send five rounds downrange using perfect sight alignment, sight picture and grip and trigger press. If you have a group on the target less than two inches you can now see what your PoA vs. PoI is. If your group is greater than 2” rested at 15 yards or less, stop. Have someone else who is an experienced and competent shooter shoot exactly the same set up. If that person also can’t produce a sub 2” group, stop. You may have a real mechanical issue.
If the elevation of your <2” group is not centered, move the target closer or farther until you find your elevation for your gun and ammo. Adjust windage. You’re zeroed. Change ammo. Do it again. Variations will be within a couple of inches.
If you want a different specific elevation PoI for your particular PoA at a chosen distance, you will have to make sight changes.
You can expect only a few inches of elevation variance between 7-20 yards shooting. Your shots will be on a 14” target. It’s not a huge deal.
The factory did not put a different sight on your gun than everyone else’s, or machine parts and assemble them with tolerances so out of spec that you have to worry about whether they screwed up your aiming point. They have delivered to you one of a million mass manufactured guns that performs within an acceptable standard of accuracy, the details of which vary slightly based on shooters’ choices.
Really, you just need to shoot the gun in as controlled an environment as possible to eliminate as much shooter error as possible. If you can’t do that, you simply cannot zero your gun, no matter how much information anyone gives you.
