Explosia is the maker. Lovex is a brand name they own. On page 9 of their reloading manual, they describe S062 as:
That's from the horse's mouth. No mention of IMR4320.
On pages 39, 40, and 41 of this load data they list data for 8 different 180-grain bullets, all of which include using S062. The pressures you see are for the maximum load only, and not the minimum load. The Garand doesn't mind full pressure (very strong receiver), but it does mind the op-rod being exposed to an excessive pressure impulse. Lowering peak pressure does not necessarily lower that impulse because the bullet is slowing down, giving the gas port longer exposure to whatever pressure is there.
I know that observation goes against a lot of conventional wisdom about Garand-appropriate loads being intended to minimize gas port pressure. I've run the gas impulse calculation from QuickLOAD data and found the weight of the bullet far more of a factor than whether the powder charge is full or not, with middling loads of the lightest bullets being easiest on the op-rod, but for 168-grain bullets and up finding the gas impulse applied to the gas port is greatest in the low-ish to middle range loads that most Garand owner load to, and is actually smaller at higher pressure because even though the muzzle pressure is higher, the bullet is going enough faster that it shortens the time the gas port's exposed to it more than the pressure has grown.
The above was confirmed in actual gas port pressure measurements made by garandgear.com's engineer, Chris, who devised their hollow gas port plug. He measured pressure in the gas cylinder produced by increasing loads of IMR 8208XBR, and the hotter the load, the smaller the gas cylinder pressure was. So I think the medium load wisdom was always based on historical military loads combined with how the shooter imagined the pressure relationships worked out, but not on measurements.
"S062 High density, single base, tubular propellant similar to Accurate 4064 most suitable for 8 x 57 IS, .30-06 and other ball cartridges."
That's from the horse's mouth. No mention of IMR4320.
On pages 39, 40, and 41 of this load data they list data for 8 different 180-grain bullets, all of which include using S062. The pressures you see are for the maximum load only, and not the minimum load. The Garand doesn't mind full pressure (very strong receiver), but it does mind the op-rod being exposed to an excessive pressure impulse. Lowering peak pressure does not necessarily lower that impulse because the bullet is slowing down, giving the gas port longer exposure to whatever pressure is there.
I know that observation goes against a lot of conventional wisdom about Garand-appropriate loads being intended to minimize gas port pressure. I've run the gas impulse calculation from QuickLOAD data and found the weight of the bullet far more of a factor than whether the powder charge is full or not, with middling loads of the lightest bullets being easiest on the op-rod, but for 168-grain bullets and up finding the gas impulse applied to the gas port is greatest in the low-ish to middle range loads that most Garand owner load to, and is actually smaller at higher pressure because even though the muzzle pressure is higher, the bullet is going enough faster that it shortens the time the gas port's exposed to it more than the pressure has grown.
The above was confirmed in actual gas port pressure measurements made by garandgear.com's engineer, Chris, who devised their hollow gas port plug. He measured pressure in the gas cylinder produced by increasing loads of IMR 8208XBR, and the hotter the load, the smaller the gas cylinder pressure was. So I think the medium load wisdom was always based on historical military loads combined with how the shooter imagined the pressure relationships worked out, but not on measurements.
