I purchased my garand on an impulse roughly a month or two ago, and was unaware of the need to reload, so had to do a intense burst of research in the week it was in transit, so I could shoot it the day it arrived...
Still fresh in my brain for now, but please note I am not an expert, or claim to be. Just someone who has time on the computer and can share what i've learned with my garand.
I use, IIRC, 48.0 grains of imr4064 pushing 150 gr hornady bulk. This is my "bulk" load, not tuned, it's just for fun on the range, learning the rifle and using it to teach others to shoot.
Look at velocities and pressures produced by the burning of the m2 ball, this is what many modern loads try to replicate.
Many reloading manuals with 30-06 included in them (read: all of them lol) look for high velocities, and higher pressures, as you already know, with loads built for modern rifles.
as mmMatt stated, the 7th edition of the hornady manual does have information about reloading for the garand, however I find them to be limited on the powder selection.
Please do take care to avoid the FEDERAL primers, they are soft and can slam fire..
When I started my reloading, I used the 30-06 data section of hornadys manual, not the garand. (there was no imr4064 for 150 grain in the garand section)
I selected the load that produced roughly 2700 fps.
Seated the bullet a little bit longer than the cannulure (S.P), trying different lengths, to ensure function.
Make sure you do remove any excess material in the primer pocket, as again, high primers can cause slams and spontaneous disassembly.
signs your load may be to hot with the garand are : the clips prematurely ejecting, increase in recoil, a change in where your brass ends up.
if you are really concerned, purchase an adjustable gas plug from pocketfisherman. they have ports with vent excess gas.
One of these, with reloads with ensure your garand has a long and happy life..
Hope this helps!