Sometimes I daydream of owning a Garand.

Do they function well with hunting bullets, or is it just 150gr. ball?

Is there an upper or lower bullet weight limit for reliability?

Thanks-

A Garand will be fine with Spire Point or tipped bullets. I find that 150-165 grain bullets work best. Some even load 125 grain bullets for close range match shooting. Best to keep weights from 150-175 grains but I've read that some shoot 180's. Main thing loading for a Garand is using Garand safe powder. Powders should be in the burn rate from IMR 4895 to IMR 4064. Slower powders will damage your rifle by bending the op rod. You don't have to only shoot FMJ's. Do not buy factory 30-06 ammunition for your Garand UNLESS it is advertised specifically for M1 Garands.

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excellent advice and will add I used to hunt with 180 hunting bullets in my first M 1

You also have the option of buying a replacement gas plug (mine is from Garand Gear) that operate using different methods to reduce the force acting on the op rod so you can shoot modern ammo. I load for mine using Hornady 150 FMJ and a light load of IMR 8208 XBR. The gas plug is cheap ($40) insurance that nothing is getting over stressed.

150-172 grain soft points will be fine. I use 110 grain Sierra Varmiter bullets w/ IMR3031 or lately, with much better metering and just as accurate, H4895. No issues, lighter recoil, and great accuracy.

I have a 308 & 06 Garand. They both do fine with commercial SP bullets. Upper limit should be 165gr IMO with medium burn powders. No pushing max 06 or 08 loads if you want your Garand to last another 80y.