Now I know this may be rather simple, logical even which is why it was never thought of by the OP
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Use a target that is meant for such scopes ..................................... Simples
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They are available some have Four blocks on then with a cross left bare in the middle and one simply aligns the reticle with the blocks and voila the shots fall into the middle if the scope is set up that is. This is one type I have used in the past:-
The red spot is a price sticker I added as I was trying the factory irons.
This is one I made up on graph paper then got photocopied:-
Trying some cast bullets in a .303 Martini Muscat again with iron sights.
But it gives you the idea of the type of target that works with a heavier reticle. Not all of us like fine reticles as they are a handicap in poor light like dawn and dusk when hunting.