I got a bunch of cast bullets (some from bullet barn and some not) from a fellow who told me he shot a large grizzly with a Bullet Barn 300 grain hard cast bullet from his .45 Colt leve action rifle, at about 40 yards, and the bear went down permanently with one shot. Apparently slightly quartering away, shot through the boiler and into the off-side shoulder. Bullet did not exit, but was deep into the smashed off-side shoulder.
My father shot his last two moose with hard cast 340 grain bullets from his 45-70. Expansion was minimal, but penetration was tremendous.
I've got loaded ammo in .454 Casull, 45-70 and 9.3 x 62 all waiting to take game; so personally, I think you're fine hunting with hard cast...