What Mthuntr said.......sounds to us like you've only loaded 48.0 grain charge weights and are going to hit the range. I generally load in 1 grain increments from about 4-5 grains below max and start shooting from the lowest charge weight, looking for pressure signs as I go. Does your Lyman book cover pressure signs? I just looked in my latest hornady manual and they have a pretty comprehensive section on pressure signs.
About COL.....you are ahead of the game if you are figuring out if the cartridge fits the magazine. A lot of rifles have throats that allow the bullet to be seated way out there but the COL is too long for the magazine.
Regarding COL and seating depth measurements......
I use the Hornady OAL gauge and bullet comparator for COL and seating depth measurements.
https://www.hornady.com/reloading/p...ools-and-gauges/lock-n-load-bullet-comparator
https://www.hornady.com/reloading/p...tools-and-gauges/oal-gauges-modified-cases#!/
Another thought.....If I'm working with a light-for-caliber bullet like a 40 grain .224 bullet......sometimes the throat is so long that the bullet would be out of the case mouth if it were seated close to the lands. In this case, I will try to get a bullet diameter's worth of bullet length below the mouth of the case. In other words, seat a .224 bullet .224" from base of bullet to case mouth.