Mapsjanhere,
Yes, lots of Garand loads out there. The Hornady's are super-mild. Well below what was being shot even two decades ago. I recommend you go to Wolfe Publishing's web site and find their back issue page and find
Handloader #114, March-April, 1985 (the Wolfe links are mislabeled April-May, but it's the same issue). John Clark's article on Page 30 has a number of match loads listed. Be aware a lot of components have changed since then, so you want to work up to his load levels carefully.
Hornady makes a commercial match load for the Garand featuring their 168 grain A-max bullet. It is, by all reports, a good shooting round if you can afford it. Otherwise, surplus M2 ball (if you can find any) and HXP ball (CMP) are your best choices for commercially rolled.
One change since Clark's article was written is the CCI #34 military-hard primer is recommended to help mitigate the chances of getting a slamfire. Like military primers, this is a magnum primer (the military uses them to maintain adequate ignition in extreme cold) and they do help a ball powder to ignite better, if you use one. The main thing with these primers is to seat them deeply enough. Many people don't and that promotes slamfires. They should be between 0.003" and 0.005" below flush with the lip of the primer pocket. This is a slight crush fit.
To test for adequate primer seating depth, set a flat screwdriver blade over the primer pocket that spans it lip to lip, and make sure a narrow strip of standard typing paper feeler may will slip between the primer and the blade without interference. I used to suggest just laying a straight edge across the case, but I've noticed that resizing often bends the rim back slightly, which would raise a straight edge enough to give you a false OK on seating depth. The rims of new brass are often bent back a little, too, from forming, so if you check new loads to compare, the screwdriver blade is still best. After awhile you will learn what a properly seated primer feels like to your finger.
Powders for the Garand must not be slower than medium burning rate or they produce excessive gas port pressure. IMR 4320 is usually the slowest powder recommended, However, a ball powder called WC852 was developed for M2 ball ammo and is sold in canister grade for reloaders by Hodgdon as H380, and Hodgdon shows it's even slower than IMR 4320. So I'm not sure the old rule is entirely right. If you have a new op-rod, this powder should be OK. But if you want your op-rod to last a long time or if it is used and has carbon caked up under the piston (which often covers up tube corrosion) I would go with something faster.
Slower powders can be safely fired in the Garand even with a less that robust op-rod if you use a vented gas cylinder plug to drop that excess pressure. Brownells sells a couple of kinds. However, they won't be allowed in a service rifle matches as they violate the outward appearance rule, and in the John C. Garand matches, they also violate the as-issued rule.
In addition to John Clark's loads for 150 grain bullets, I have recently been using Vihtavuori N135 powder. This stuff is not cheap, but it's clean burning, has enough bulk to fill the case better than most suitable Garand powders, and it produces lower gas port pressure than IMR4895. Vihtavuori's manual lists 45.8 grains to 49.8 grains for a 150 grain bullet, but their COL is a little longer. This is with a Lapua case and a standard large rifle primer.
For match shooting, using the #34 primer and a Lake City case and the 150 grain Hornady FMJ seated to Hornady's 3.185" COL (correct cannelure placement at the case mouth), my particular rifle has been running well with both the 45.8 grain starting load of N135 and with about 48.8 grains (when I want to shoot to 600 yards). N135 is a short cut extruded grain that meters well in the Lee Perfect measure as well in my extruded grain go-to measure, the JDS Quick Measure. The 48.8 grain load fills the case to the bottom of the shoulder even after some tapping to settle it. Obviously, you need to test this load for yourself to get an accuracy read.
The other load not in the article and that I usually mention for completeness is a load that mimics the last DCM purchased lot of M72 Match ammunition. This mimic load is, a Lake City case, CCI #34 primer, Sierra 175 grain MatchKing bullet, and 46.5 grains of IMR 4895 seated to a COL of 3.330".
. I remember reading on several occasion that the typical Garand ammo was not as powerful as today's 30-06 loads, and can stress op rods and other parts. Does anyone have a preferred load specifically for shooting the Garand?