Gentlemen;
Since my last post I have fired the M48 over as many of the long-range silhouettes as the sights would reach - this was out to 500 yards.
I experimented carefully with the various peep extensions I have in my shooting box and none would work.
Here at home I put together a new combination that allows me to increase the height of the peep by 0.4375. ~ Fortunately this additional height corresponds closely to the 500 yard setting - after the sight staff has been lowered all the way down to +6 minutes from the bottom of its travel in order to zero the peep itself at the same elevation as the staff with no modification at +61 minutes on Lyman's scale.
The modification looks a little weird but the bolt handle clears the sight - which was the problem that prevented me using my old methods.
Next will be the move on out in distance to our maximum range of 835 yards.
I'll let you know how it turns out.
Forrest