Thank you very much guys for explanation on 20 MOA.
One more thing, almost forgot. I purchased Varmint (Target) spring from Gun Shack. Ones I open rifle for maintenance, I found that spring on my Stealth looks exactly the same as spring I received. I counted coils, measured wire diameter, everything to get an idea if there any difference and found non. I cranked original spring down to minimum pull weight and found that spring doesn't need to be replaced. I measured 1 lb 10 oz. I am good with this number.