Re: Iron sites on bolt rifles
If you can find FM 23-5, the 1958 version (later models dont include the M1C/D), it has a great section on range estimation.
Besides the sight, the scope redical also can be used for range est.
For example the M-84 scope has a 3 MOA post sight. Meaning the post covers 3 MOA per 100 yards.
So looking at the 19 inch E-series target, 3 MOA covers 1/6 of the target. At 200 it would cover 1/3, 300 about 1/3, 400 yards 2/3s, etc etc.
So using the relation of the redical on the target gives you the range.
Don't discount all those old military marksmanship manuels, they beat the crap they put out today.
Sure some things are wrong (Using 5-23, the Breathing Part is something I totally disagree with), but over all they are better manuels for teaching marksmanship.
As to the Redfield sights, they are a lot more durable then many lead us to believe, but they are light, they don't have to be carried on the rifle, yet when they are, you don't have to re-zero the rifle.
If we go back in history a bit, one of the main reasons we went to another rifle instead of just changing ammo on the Krag was because soldiers, after dealing with the Spanish Mausers in Cuba wanted a clip fed rifle.
Lets say the sniper carrying a bolt gun wants to use his rifle as a battle rifle, with rapid fire capabilities. You can clip load a bolt gun with irons, you can't with a scope unless you have an offset scope like the Garand.
Don't discount the old rifle set ups, they still work.
I have a Model 70 1000 yard rifle that is set up for scope (any rifle any sights) and irons, Redfields (for any rifle iron sights).
Checking back in some of my old score books I've averaged better scores with my Redfield Olympic then I have with my Weaver T-10.
(The best 1000 yard score I fired was with my M1A in Service Rifle Match).
When I was running sniper schools using the M1C/Ds, we found out a lot of guys could shoot as well to 900 yards as those with the M-84s, and were every bit as good using the irons for range finding as the redical on the M84.
Anyway go out and play with your irons doing range est. The worse case is you'll have some fun.