If anyone has done this...by all means please step forward and be THRASHED and otherwise deservedly ridiculed for your efforts!!!
Seriously...why is it that people want to F-up an otherwise perfectly good battle rifle and a historical icon by adding all sorts of tacticool @#$% to it? Let them well enough alone, damnit. OK...rant off.
There have been various attempts over the years to make the Garand more "tactical" in a sense (if you want to call it that), including shortened barreled versions like the Tanker (and others), synthetic instead of traditional wood furniture, all sorts of half-assed scope mount setups like the scout rails, rear sight replacement mounts, etc. (not including the G&H M1C setups and other period-correct mounting systems like that of the M1Ds), and pistol grip stocks (Sage Intl makes the EBR chassis in various configs for the Garand, and you can use the Nigerian BM59 stocks with grips, etc., etc.). Again...rant back on momentarily...there are literally tons of aftermarket parts and accessories available for you to thoroughly "bubba" your Garand to your heart's content (if you can stomach doing it).
As for brass, reloading for the Garand, etc., etc... its best to have a search around and glean some good information on the particulars of safe and accurate reloads for the Garand. Because of the nature of the Garand, there are several issues that need to be addressed when reloading for them, including seating primers properly, restrictions on powders that will/will NOT work safely/properly with the Garand because of burn rate issues, bullet weights that can/cannot be used safely, differences between reloading commercial and GI/Surplus brass, etc., etc. There are also some adjustable plugs that will give you more flexibility in terms of the ammo/loads you can safely use like the Schuster adjustable gas plugs for one example.