Hello all,

I'm trying to figure out how much distance I've got left on my Pedersoli tang sight.  It's at 1.60 on the scale at the 100 yd zero.  I've got about 140 MOA left on the sight.   
It's a Pedersoli rolling block with the heavy 26" barrel and about a 30.25" sight radius.
I'm shooting 405gr with 25gr of 5744.  I'm going to start loading a 500gr with about 25gr of 5744 for beyond 200yds....if I can go much further with the sight.
To make it worse, it still has the stock front blade sight which is .304 above the barrel and about .371 from the bottom of the dove tail to the top of the blade and the shortest Lyman 17 I want to put on it is .404 dovetail to center.

Any help would be greatily appreciated,

Andy