How would a non copper hard cast bullet perform on big game. Say 30 cal in SAUM or 7mmRM or .243. Could one achieve good accuracy with them. Or are they better suited for round nose calibers i.e. 30/30? Never thought about it.

Assuming you are talking about a lead/tin/antimony alloy bullet you'd have to keep velocity under about 1900 fps. As long as range is reasonable they will perform fine...usually some good expansion and superb weight retention. You simply can't drive them too fast or they will lead you barrel even with a gas check.
You could try a paper patched bullet as I have seen some go as high as 3,000 fps...but that's a VERY specialized loading that requires more tinkering to work than I have energy.

Jason, 'tis a can of worms you open here, but for the sake of discussion I'll throw in a few opinions and a little experience.

Opinion: nekkid lead can be driven fairly fast if you have a good barrel, proper alloy and perhaps most importantly, proper sizing. The latter is more important with softer alloys but is not to be disregarded with hard. Hard cast bullets used on big game need a larger diameter that the rifle bores you mention, perhaps .40 or larger, and they need a substantial meplat to inflict a wound channel that kills quickly. This works well in handguns but obviates some of the advantage a rifle may have at longer ranges due to the lower BC inherent in that design. You will find more input on this in the Cast Bullet Forum if you care to pursue it.

Rifles and cast bullets intended for target shooting can be quite successful however, as long as you do your homework and have some thoughtful patience with the process. As an example, I have an old Blanch gun in .25-20 that shoots under 2" at 50 yards using lead...considering open leaf sights and my eyes it is quite remarkable. Talk to folks who do a lot of this, they can clue you in. I don't, as of this time, cast bullets...

Facts: Paper patching is not terribly difficult but there are some points that need to be kept in order. As a simple matter of reference, PP factory loads have been produced in the past for .22 caliber rifles(.22 WCF), and as large as you want to go. The primary benefit is that the paper acts as a jacket and promotes much higher velocities without concern for leading in very soft alloys. Sizing is important whether using black powder(smaller) or smokeless(larger). Paper selection is important as well, it must be free of abrasives and of proper thickness. Onion skins are popular for this, the thickness varying with each weight category, ie. 9# OS is approximately .0025" dry, and shrinks to .002 after drying...some don't wet the paper though, it's a matter of technique.

In short I found the idea of PP loading more convenient than setting up for casting, and wrapping is not tedious at all, once you are set up for it. Two sources on this are, "The Paper Jacket" by Paul Matthews and http://www.iastate.edu/~codi/PPB/PPB.html

I've read some of Matthews other works and found them wanting in many regards, but on this one he does a good job. Obviously has some hands on here rather than just theoretical rumminations. Some of his guidance didn't work for me, but hey, that's the way it goes. It WILL get you started, and PP bullets are killers. Alloys are generally 1:20 or softer, I use pure lead myself. Velocities are limited by bullet diameter, twist rate, alloy and rifling depth. The Marlin Micro-groove guns will shoot PP okay FWIW. Practical floor on diameter for this past time is about .30 cal, but that is an OPINION. If you want to fiddle with something smaller have at it. What happens as you up the velocity with PP bullets it that they begin to strip the rifling in smaller bores with quicker twists. I experienced this around 1700 fps with my .44 Mag rifle. I suspect that if I wanted more speed a 1:20 alloy would do the trick up to about 2000 fps. Hard alloy PP may go as high as 3000 fps as indicated in the previous post but you will have issues with lack of obturation unless the pressure is quite high. Go to the Small Game Forum and look up a thread called "I hate Hogs" for some pictures of recovered bullets, both mine and another fellow shooting a .45-70. FWIW, it takes me about an hour to patch 50 bullets from a cold start...Cutting paper, wrapping etc. After that they load just like any other lead bullet. I use a taper crimp by the way, roll crimps are a no no in this endeavor. If your goal in hunting, 50 PP bullets will last several seasons, and if properly loaded are quite durable. The load I used in the thread just mentioned is not far from 3 years old. Also FWIW, the 30-30 is an ace for PP loads, a 170-190 grain RN design will give you plenty of punch for the freezer though I'd suggest using something akin to Lyman #2 alloy if you want to take it up near 2000 fps.

Hope this helps answer some questions...if you care to pursue the PP thing I will be happy to assist, just PM or email me. If you want to use nekkid lead there are more qualified gurus to be found in the neighborhood.

Thanks, that answers my questions.