I don’t know how many times I’ve walked into Cabela’s, Dick’s Sporting Goods or some gun shop and  picked up a rifle, whether it was a hunting rifle or a military style rifle and noticed that the scope was not mounted correctly.  So many people lack any gunsmithing or armorer skills that they don’t have the slightest clue how to know if the scope is level.   I usually mount all of my scopes while at a firing range, and once I think i got it, I make a few shots on paper, adjust the elevation about 4 MOA and then take a few shots  more, once I know the elevation is adjust the point of impact up or down, and not moving the way the windage adjustmants would move POI, then I know I got it for sure.  Some people seem to not want to put the effort in and when  they see me hitting steel plates at 400yds, they don’t have the slightest idea how I can do it.

The above mentioned are some suggestions on how to verify you have a leveled scope, but you can make things a lot easier by buying an Eotech or an ACOG.   If you want to make your longer range shooting very easy Trijicon ACOGS for sale are probable the best option for you.  For instance, the Trijicon TA01NSN has bullet comp out to 600yds for the  62GR SCBT or the M855 round out of an M4 Carbine.    You will be able to nail targets ad varying distances just by adjusting where you put the crosshairs.  There are other reticles that you can use for different ranges but all of them are things you will want to research.  The Chevron reticles are fast outselling crosshair reticles.