lachesis - two things
" It appears then that it's tough because I'm not cooking it long enough?"
-that is one reason..the other is you are possibly over cooking the meat in the skillet to begin with.
also, If you just attempt to simmer sauce for a few hours straight out of a jar it may get too thick and nasty.
real bolognese sauce was the first thing i ever came to this forum looking for ideas on.
If you get a couple of cans of good whole tomatoes, and crush them by hand and cook them in their juice with your meat, you will allow the liquid to cook down and sauce to thicken over time. people also often add beef stock, red wine, etc
It's really worth putting the extra effort into a bolognese.
3..2..1.. HUSTLE! HUSTLE!