With so many different opinions on the question of penetration of hollowpoints vs fmj in this caliber it would seem that a round like the Glaser safety slug would receive strong consideration because it has a known result. When it hits there is no doubt what will happen the target will know it has been hit. I understand that it will not penetrate as deep as some rounds but would not the effect of the Glaser result in more of a chance of stopping the threat then counting on a fmj or hollowpoint that might not expand hitting a key spot? Of course this (which ammo is best to use) discussion may just end up like fishing you use the lure you have the most confidence in.