Yes, as others have said, 45# is 45# is 45#... at full draw the holding weight will be 45#, but it is how you get there that can be very different....
A bow that increases its pounds per inch of draw more towards the end of the draw will be perceived as hard, or stacking, while a bow that keeps a steady increase, or like the hex 5 limbs actually drops it's pound per inch numbers at the end of the draw wil be perceived as smooth... Everything is relative... I have drawn up bows that the owner feels is smooth that stack like crazy in my opinion....
Force draw curves don't lie though
All you need is a long bit of 4x2, a boat trailer winch, a yard stick and a bow scale...
Put a big bolt through one end of the plank with a big washer ... Pad this bolt with pipe insulation leaving the washer at the top so the bow won't pop off at full draw....

You then bolt the boat winch at the othercend and affix the bow scale to the rope on the winch... From the bolt you measure out inches of draw and Mark these on the plank, or you can glue a yard stick to the plank...
Then it's a simple job of winding the winch and reading off pounds at each inch... You can then plot a graph and see how smooth the bow really is, and at which point stack becomes an issue...