Re: Weaver 1x5 Tactical CIRT scope
Don't know how any one can come to the conclusion that the SS and the PST would be a better scope unless they have actual experience with all three.
The SS, made in Japan (a good thing)
The Weaver, made in Japan, likely the very same factory. I would think that both are made at light optical.
Viper PST, made in the Philippines.
To the OP, no, it does not matter what increments the adjustments are in. As you have noted, it is a BDC reticle, not a ranging reticle. Although you can range with it, considering the application for this type of scope, ranging isn't really an issue.
Your biggest issue will be to figure out the holdovers with the trajectory of your cartridge, since it is not the cartridge that the reticle was designed for.
MUCH easier to do with a mil or moa reticle, as you can plug that into JBM to get your holdovers (close enough with the 7.62x39)