I am not familiar with the rules for LR BPCR. Are you required to use a tang sight? CPA makes an adapter (two actually) which clamps on the rear scope block and runs a rail to either the left side (Redfield) or over the top of the action (Anschutz) for a receiver sight. I have seen these in use at schuetzen matches. These sights are both cheaper and probably better than most tang sights selling for less than $400. For one thing, they have clicks!