Well imo it all depends on ammo, you can have a gun shoot 4-5 moa with some ammo and 1 moa with the other. You can't really say a gun as crappy accuracy unless you tryd diffrent bullet weight, bullet type and brand.
On another note yes it's more complicated to make a good solide feeling action with a double stack mag; so I suspect that ruger were not able to make there m77 action and mini 14 mag work. But to me the fact that is proprietary mag would make me very weary of uying this gun if I was in the market for such a thing.