You could try and use the rifle as it was intended, shooting head up.
I think its a bit of a shame that everything seems to come back to shooting from a bench, or prone (although you can shoot this style of rifle in that position).
If you have challenged yourself to learn to use a two stage trigger you can surely learn to shoot head up - and you'll find yourself in the fine company of literally millions of European hunters - who between them shoot a lot of game !!