Just because they're illegal for hunting in some state, doesn't mean there is a "good reason." There are a lot of gun laws without a good reason.
And without additional information it would be foolish to conclude there is NOT a good reason.
If you want to kill an animal, first of all the bullet must get to a vital organ. A solid is more likely to get to a vital organ so, if the gun you are shooting is of marginal power for the animal you are hunting, a solid would be the best choice.
Not necessarily true. I have put fmj’s through the vitals of coyotes and was very unhappy with the results. I shot a buck antelope with my 7mm Mag using Barnes 160g XLC’s. The first two shots went through the lungs, above the heart. The angle was a slight quartering towards me but more broadside. The first caused the buck to stop walking. It may have gone down for a moment, I forget, but it was on its feet when I took the second shot. The buck lowered its head and started coughing up blood, then laid down but kept its head up as if sunning itself. I decided to work my way around a hill for a closer shot and 20 minutes later I was in position for another shot. The buck spotted me, got up and started walking away. A third shot hit the heart and ended its misery.
OK, XLC’s are not FMJ’s, nor are they solids. There are, however, many stories of the ‘X’ type bullets failing to expand and acting as FMJs. After examining the wound tracks, this is what I believe happened with at least the first two XLCs. The third wound track showed more damage, which I took as indicating possible expansion. The original ‘X’ type bullets, which includes the XLC, also have a reputation for losing their petals after expansion, leaving a marginally expanded caliber diameter bullet to do the work. In other words, after losing their petals they act somewhat like a solid.
The point is that two shots to the vitals with the XLC’s at magnum velocities did not produce the result that a .30-30 with Power Point bullets would have. As someone else stated, if the gun has marginal power, maybe its better not to shoot than to trust an FMJ to do the job. Had the angle been bad and lots of penetration required, the XLC’s would probably have reached the vitals – the question is would they have performed any better? I doubt it. Based on that experience I did not use the XLC’s on elk that fall as originally planned but went back to my old standby of Grand Slams – which performed perfectly. If you want reliable expansion AND damage AND penetration, stick with a bullet like the Partition, A-Frame, Trophy Bonded, North Fork or even the TSX ( which has a better reputation than the original ‘X’ family), or even the new MRX. Save the FMJ’s for paper and steel.
If you want to kill an animal fast, the projectile needs to do a lot of damage to a vital organ. An expanding bullet, provided it gets to a vital organ, will do more damage and could be expected to kill faster at least where non central nervous system shots are concerned.
Yup, expanding bullets do a great job – whether CNS hits or not. I would not chose a bullet that HAD to hit the CNS to be effective, as the CNS represents a relatively small area.
It absolutely cracks me up that solids are used on elephant, cape buffalo, etc. as projectiles of choice and are then thought by some to be ineffective on our relatively soft whitetail deer targets.
When people compare FMJ’s to the solids used for Africa’s big game, I just have to laugh. The solids used in Africa are large diameter, blunt-nose (FP or RN) projectiles, not spire pointed FMJ’s. There is a HUGE difference in terminal performance. A lot of .45-70 hunters use 400g-500g hardcast bullets with large meplats (big flat spots on their noses) at relatively slow speeds. These bullets, while legal every place I know of (including places where FMJ’s are not), are incredibly effective even though expansion is minimal. The diameter, bullet weight and nose configuration make the difference.