I was thinking about this yesterday as I was loading for my H&R in 30-30
What bullets are going to expand well at 30-30 velocities?
I have been toying with i idea of loading some 220g round nose in it.
See what happens
You have to stop looking at it as 30-30 velocity, you have to look at the given velocity itself, I had this discussion on here as well and was told to just stick with 170gr FN and be done with it, even with the math shows significant velocity differences at range and therefore energy when moving down to a 150gr spire point bullet.
I started to compare to the 308 Win, a 150gr Interlock bullet in that cartridge has the following book velocities, 2820 at muzzle, 2553 at 100 yards, 2301 at 200 yards, 2063 at 300 yards and 1841 at 400 yards. The velocity listed by Nosler for their partition is 1800fps as a minimum, so based on that ideal minimum the 308 Win will expand properly to around 400 yards.
Using available data through Nosler and Hodgdon I worked up a chart based on a 150gr Partition with a muzzle velocity of 2400fps, this may be a bit high but so is most of the book numbers, including that 308 Win. With this setup and BC the velocities look like this, 2400 at the muzzle, 2186 at 100 yards, 1984 at 200 yards, 1794 at 300 yards. Essentially you are losing 100 yards of bullet expansion velocity with the 30-30, this is no pop gun. Based on the energy numbers there is about 1450ft lbs at 150 yards, 1000 ft lbs at 350 yards, so you should have no issues with a 300 yard expansion on deer if you can hit one that far.
I have also been told that there is no benefit over a 170gr bullet, so I worked up those numbers as well, the velocity at the muzzle will be about 2300fps, down to 1446 at 300 yards. The energy would be 1997ft lbs at the muzzle and down to 789 at 300 yards, so which one should work better, the 150gr partition spire point or a 170gr RN?
If you google there is a list of bullet lengths, be aware of the lengths of many of the bullets like the SST and high BC bullets are significantly more than the RN 170gr, so you are pushing that bullet back into the case significantly. I tried to find a bullet length that was close to the same length as the 160gr FTX bullet, the 150gr Partition comes in close. Do not expect to crimp on that case but why should it matter? The neck is long on a 30-30 and the neck tension will be high, since you are not absorbing recoil as if it were in a tube I do not see why a crimp would be needed. If you wanted a crimp you can still crimp with a Lee Factory Crimp Die on to any bullet, no cannelure needed.