If I understand this correctly, you have a very hard bullet that has a plain bause, and you are considering using it for hunting? Well, the plain base will most likely restrict just how fast you can push that bullet, which in turn will probably prevent much expansion on game. usually plain based bullets can only be pushed to about 1400 FPS or slightly more. I have have run some to the 1600 FPS range but accuracy fell off badly.
If planning to hunt with a cast bullet, while a flat nose bullet would be preferable, I believe you'll be better off using your 160 gr. Lee bullet in a somewhat softer alloy. Something around 12 to 14 BHN loaded to full 30-30 velocity should do a number on any deer sized game, given proper bullet placement.
My bullet choice for the 30-30 is either Lyman's #311291 or the RCBS #30-180-FN. The Lyman weighs 175 gr. in wheel weight metal and the RCBS 190 gr. in WW metal. I load the Lyman to 2000 FPS and the RCBS to 1950 FPS. Both kill deer handily with good chest cavity shots. Stay away from the shoulder if at all possible. Makes one hell of a mess if you hit the shoulder bone. I've taken 17 deer with those loads, most of them with the Lyman. There is also Lyman's #311041 which is a flat nosed version of #311291, but I have never gotten that bullet to shoot well in any of my 30-30 rifles, or any other 30 caliber rifle. Yet, I gave some to a friend and they were very accurate in his gun. Go figure.
Paul B.

Paul,
It's easy to explain why your friends gun shot your bullets well...
Cast bullets you get from someone else are like stolen watermelons, they're just BETTER!