That sounds about right. Some magnum pistols would presumably do pretty well against breastplates, but most pistols fire smaller-caliber rounds and are not generally designed with armor penetration in mind. The smaller concealable pistols, say a .22 caliber, can be hard pressed to penetrate even human bones - there are reports of bullets bouncing off the surface of the victim's skull. On the other end of the spectrum you have .45 caliber ACP (something like 11 mm rounds) which will likely go through a breastplate with no problem, provided you can get a good head-on shot which doesn't veer off to the side. You can get some novelty pistols that fire .50 caliber rounds, and those will probably blow through breastplates (after dislocating your own shoulder perhaps).Jester of the FoS wrote:I recall Deadliest Warrior showing pistols were not particularly effective against breastplates. But rifles were.
Rifles as compared against pistols tend to use larger calibers, heavier bullets, and the barrel length is much longer, meaning a much greater muzzle exit velocity.
Rifled slugs for shotguns can go through the industrial-grade bulletproof plastic polymer they use in bank windows. The only other commonly available round that does this is a high-caliber rifle round - something like a 30.06 from a sniper rifle. Individual assault rifle rounds will put serious cracks in the polymer, and even a few shots will shatter it completely. I'd imagine these would make very quick work of rigid, relatively thin metal coverings like breastplates. The common 7.62 mm round, as fired from AK47 assault rifles, can penetrate bricks with little problem.
