strings stretch I believe even if they say zero stretch, therefore you will lose poundage....I have a scale at home, i check with often.....I also find my shop is usually off, though they use a big deer style scale....probably goes up to 100-300lbs, and eyeball peak weight, whereas my bowscale will let you konw peak weight more accurately, I've asked for 65....and got 62.....58...etc.....my dad asked for 60 i think and got 52......I thinke veryone should have a scale....also just to keep your bow tuned to a set draw weight, overtime if you lose poundage your arrows trajectory will change. I not certain but I could see a string stretching more early on in its life vs later on......so may be more important at first to check on it, and then only routinely later on.