QL is all about adj. it to kown data (Hodgdon-Accu powder) . Hodg. is best to start out on as it lists both psi and fps on both the min, and max loads. If you look at the C-Y- A page that first comes up when you start QL it says that some of their numbers are just numbers. The Burn Rate Number (Ba) is what you are going to change to adj. the program to the known info. Lets start with Hodg. data for the 223 Rem with a 35gr Nos. Bt LF. Their starting load with Varg. is 25.2gr. 3424fps and 38,500psi. -24" -2.280" OAL. You enter that info with their generic case vol and bullet length that come with program. Now hit the "Apply and Cal" button and it should read 32771psi and 3258fps . This is where you start adj. the Ba#. Next to the Ba# is a box with a hand holding a pen. Click on it and you can now adj the number up or down till the fps number is the same as the Hodg speed. Hint ---the number is 6570. Record that number as you will need it to adj for you cases and gun ********* DO NOT CHANGE ANY OF THE OTHER NUMBER, EXCEPT FOR Ba, FROM HEAT OF EXPLOSION TO PROPELLENT SOLID DENSITY.******* Now you adj the Ba for the pressure that Hodg shows. Hint (6746). Now do the same with the max loads. You will end up with 4 Ba numbers. 2 for the min and 2 for the max loads. Now you can adj for your gun. If the case vol is different than the generic change it- barrel length-OAL of cartridge. I would start with the Ba for the starting load pressure of 38500psi You would lower or increase the charge weight till it is the 38500psi. With that charge of powder you then enter the fps Ba number and it will tell you the approximate FPS. For max loads that don't show psi you can only approximate????? that they are max psi for that cartridge.