Well, Hodgden says 4.3 - 5.3 gr. I don't find their data too conservative or too hot. Their OAL is 1.200" which is usually short for me. This is for LRN or FP FMJ bullets.
If not sure of OAL, I would load 10 at 4.8 gr at OAL's of 1.2, 1.22, 1.24, 1.26 and 1.27. Then plunk test all of them. If they all pass, shoot them all. If you have any FTF's or FTE's, in a good gun, they are due to the action speed being wrong due to the load pressure and more importantly the OAL. You will likely get a range like 1.22 - 1.26 which work fine. I would choose 1.23 - 1.26 based on experience with my gun. Not knowing your gun, I would lean long since the pressure will be higher when you get your full house loads in the gun. So, I would be thinking ~ 1.25. Your gun, you will have to prove it out.
Then, with an OAL which works like 1.25", I would make loads from 4.3 - 5.3. I would probably make 4 loads for 45ACP. 4.3, 4.5, 5.0 and 5.3. If these were all fine and 5.3 was the most accurate, then and only then I would try another set of 4 like 5.2, 5.3, 5.4, 5.5. I would exceed the max slightly looking for the load which gets slightly worse accuracy, flattens primers or exceeds the load manuals max velocity adjusted for barrel length and my gun vs published velocity.
So, basically I'm saying exceeding the manuals max load is not good, unless you have a couple of ways to detect over pressure and have some reason to believe you can like your OAL being longer, other higher published charges, or you have something fundamentally stronger like a bolt action 45 ACP, Ruger 45 ACP revolver, T/C in 45 ACP.
BTW, the range guys sound like us. . .full of hot air sometimes. Without knowing your gun, primer reads, velocities, accuracy, etc, anybody is just guessing.