A few months ago, when I first attempted to match a tune to bpm, I started out twice as fast. Then I started to think about drumming, and how everything is divisible. I can count the eighth or16th notes, but that ain't the bpm. As soon as I got in the ballpark, I started feeling, for lack of a better word, the pulse of the tune. I relate that pulse to the bpm, which, so far, been right on. I'm thinking I will be told if I am mistaken......

As a practical matter, if you believe the different audio projects are exactly on the beat, you should be able to just import the borrowed drum and bass into your project and slip stretch the imported audio until it lines up with the rest of the project. If it does line up you are done. If not...

Hi, again. Do you count 16th, or 4th? Maybe it would make a difference? (1234, or 1,2,3,4).
Anyways, best of luck.

"slartabartfast" - That was an in depth explanation. Thank you very much. You should be a Music Teacher of some sort. :)
"Zargg71" - Thanks for your comment. :)
"Brightside" - Thanks for the correct tempo. :)
"charlyg" - Thanks! :)
To all, Have a great day and remember it is people like yourselves that make it a pleasure to be part of this music community. Stay positive and Thank you very much, once again. :)

Funny that's what I said.

I record our band live all the time and we don't use a click track. 
So the songs are all at 120 by default. 
Later if I wish to muck with stuff I might try and match the tempo so I just change it. 
Audio tracks do not change with the tempo, only midi. 
Therefore you should be able to just change the project from 120 to 112? . But if those original bed tracks drifted around then it gets more complicated and that is an area I have never ventured into. I beleive you can extract a tempo somehow. 
But I have my own old backing tracks that are audio and they will match up perfectly if I keep adjusting th etempo. 
I use the count in and line it up to the grid. It normally results in a 144.25 BPM