Harry charges his rings by punching a heavy bag - are you going to put the bullet in his gloves to charge it up? The propellant in the case has a surprising small amount of kinetic energy - an actual 9 mm bullet is under a third of an ounce. Even Harry's 44 is about a half ounce.
Yeah, the movies mislead most people about the kinetic energy transfer of the bullet (i blame actors, I am with Drax on this) Jim gets this right with Harry’s shield and Duster. The rings absorb kinetic energy from normal movement, they just need to ride around in a pocket for long enough. Speedier recharge is the punching bag.
Murphy referenced steel jacketed bullets in Wild Card dealing with the Lea level Wildfae Puck (a proto Nameless).
The modified Ghoul killers would expand their force in all directions once penetrating causing the ghoul to “pop”
Mab can survive a steel jacked bullet by removing the bullet, she will regenerate from that. Iron filings would take way longer to remove, which is why I suggest them, together with a ghoul killer, disperse them into her body. I am sure Kincaid has long been thinking along these lines, like Mr Teatime in the Discworld, he has plan for everyone, as he demonstrated with Harry.
Now that’s a horrifying thought, what if Kincaid is now working for the Library of Congress? He has experience of working with an Archive.
This is why the other nations fear humanity, if we wed our technology with magic and our numbers they are doomed. Imagine a claymore with magic Fae seeking projectiles. The Fae do.