I have been working since last year to get my bow cranked all the way up to 70 lbs. Last week, I had it set to 64.5 lbs and noticed it was getting a lot easier to draw back then it was a month ago so I decided to turn it all the way to see what 70 lbs would feel like. My bow is easily adjustable with an allen wrench so I turned it all the way up until it stopped without having to apply to much torque to prevent it from stripping out. Once it was all the way up, i used a luggage scale i have to test the weight. It topped out at 67.5 lbs. Am I not getting up to 70 because of how much my strings have stretched or could the scale just be off, or could something else be wrong? I tried to google this issue but couldn't find anything.
It could be the scale, or the bow. Tough to say for sure. I would try another scale first and see what results you get. If it's still off then most likely your string/cables are the culprit.