Yanus, I use a lot of lead bullets in the .30-30 for fun plinking on metal targets. I use the 165gr. RNFP which are available in both .309" and .310" dia. These are non-gas check designs that have a 16 BHN. These are about $38 per 1,000 from Mid-Kansas Cast Bullet, Inc ($10.95 for 250).
You can drive these bullets up to 1,450fps without excess leading. But I like them at about 1250 fps. Bedlamites load recommendations will work fine with this bullet. I like Unique!
Get one of those "duelling trees" designed for centerfire pistol and place it at 50yds. BIG FUN! YeeHaa!
If a bullet is designed for a gas check, you should use a gas check or accuracy will suffer!
I don't recommend any lead bullet for hunting medium game with the .30-30. Yes, I know it can be done! But I don't recommend it!
Lead is cool!