I was hoping someone with more experience than me would answer your questions and I hope some one still will, but in the mean time I will comment.
I mold bullets primarily for hand guns. I have bullet molds for a few rifle calibers. I shoot a lot of the bullets for practice and am happy to have the means to mold bullets in a SHTF scenario, but for actual use other than practice I would prefer jacketed hollow point bullets – so I have plenty of them stored up (there are some hunting scenarios that are an exception to this). In fact I have plenty of primers and powder as well (and .22 ammo) as I started purchasing these items little by little when they go on sale – beginning when Bill Clinton was president (thanks Bill) . Even as a financial investment this has been a good decision.
As far as rifle bullets go they must be kept to a much lower velocity than I like, but again I like having a back up plan. You should be able to get 2000 fps and some people get much more. I do use gas checks for rifle bullets. I also use Lee Precision Inc. molds as most bullets from Lee molds can be used as cast without sizing and can be lubed easily with Lee liquid alox.
The .30 cal. bullets I have loaded are 150 gr. Flat nose. If I had to do over I think I would go a bit heavier, but that’s what I have. I have not tested the hardness so can not comment.
On a note to those who think maybe they can substitute black powder for smokeless powder there are a lot of things to consider. For one thing, most of those cartridges that are currently in use that were originally loaded with black powder have much faster rifling twists rates in the barrels than in the old black powder days. The 30-30 was the first American rifle cartridge released to the public shooting bullets with the then-new smokeless powder. It had a 1:12 rifled twist rate (one complete turn for 12 inches of distance traveled). This was too fast for black powder and caused the bore to foul excessively (black powder its self fowls a barrel quickly in the best of scenarios). A few years later Winchester released the .32 Win. Special with was based on the same case as the 30-30 but with a 1:16 inch twist specifically for those who still wanted to load their own with black powder. I believe the 45-70 is an exception in that it was originally offered with a 1:20 twist and still is today with modern rifles.