JHPs do they really make a big difference?

[Loyalist Dave]

The question has too many variables (imho). HP's that expand (most of the current designs are very good; older ones not so much) are better in most situations... the bigger the hole the better. BUT, when you may have to deal with a situation with various forms of cover, then YES a FMJ might be a better bet. I found out first hand in a SD situation that cars/trucks are better cover than most folks understand, and a JHP that opens (as it should) may not be able to get to the bad guy inside a car or truck, or when it does it doesn't do the job, while a FMJ will do the job. BEFORE you have to worry about over-penetration, you have to have penetration, if the bullets don't reach the badguy..., all else is moot. I would prefer to use a 50/50 mix of JHP/FMJ's in my .40 S&W, but if you are concerned about defense inside a dwelling then FMJ is not a good idea (as was mentioned in a previous post.)

LD

 

[bigfatdave]

a JHP that opens (as it should) may not be able to get to the bad guy inside a car or truck, or when it does it doesn't do the job, while a FMJ will do the job.

Hollow points don't open up when they encounter glass, metal, leather, plastic, or fabric ... they may not open AFTER passing through automotive materials, but they will punch through about as well as semi-wadcutters would.
There is no magic bullet that is best for every situation, but I'm not about to load up with FMJ/TMJ or some trick fragmenting ammo just in case, I'll take the kind that makes nice deep holes and makes a nice pressure wave as it expands ... and that meant good quality hollow-points traveling fast enough to expand reliably.
Also, if staggering your magazines makes you happy, have fun with it so long as you remember that you probably won't remember what's in the pipe after a few shots ... now on the other hand, if one was carrying more than one spare mag, why not fill one of the spares with hot FMJ? I'll have to think on that, it would require some method to differentiate the ball ammo magazine from the HP ammo magazine by touch or something ... or I could just carry a BUG with ball ammo, like a KT P32 or something similar.