Shield Charm question

[Gmariam]

I have a question. It will not change my story much, although I will have to rewrite the scene I am working on a bit. Do you think a Shield Charm (just a regular one - I went to HPL and there are several others in DH) would repel a Muggle gun fired at it?

I can't think of an instance off the top of my head of it being used to repel projectiles, just spells, so I think it could go either way myself.

Do you think a Shield Charm would make things ricochet off if? Like a spell - or a bullet? Because that's what I wrote. >.>

Thanks!
~Gina

[inspirations]

Do you think a Shield Charm would make things ricochet off if?

I always imagined the shield charm to create an invisible, but physical in properties, kind of shield. So, I always kind of just assumed that the spells ricocheted off it. I can't think of a time when we physically see that happen, but that's how I see it. And if that is the case, then I would say bullets will probably be rejected, too. It could shield you from anything if it's strong enough, I suppose...

xx

[Tim the Enchanter]

Shield charms can block physical objects, including people (like how Harry uses it to stop Hermione from attacking Ron in Deathly Hallows), so I suspect it would apply to projectiles as well - bullets would probably ricochet. However, bullets have much more force behind them than human muscle, so the Shield would probably give way after a number of hits.

So, I think a Shield Charm would deflect a certain number of bullets before being worn down. How long that takes depends on what kind of ammunition you are using (and the strength of the shield). For example, a Shield Charm might be able to absorb a 15-round magazine's worth of 9mm bullets, but an attacker with a Kalashnikov (7.62x39mm) should blast through much more quickly, since the rounds have much greater force and are streaming in at full automatic (600 rounds per minute, in the case with the AK-47). And to go completely over the top, I don't think a Shield Charm would be able to cope with a .50 calibre Barrett M82 sniper rifle, or any similar weapons that fire 12.7mm rounds.

So, for a Harry Potter high-strength Shield Charm, here are how many common calibres it might be able to stop before breaking (note that the energy levels of certain rounds are just a rough average, since ammunition of the same type can vary in force depending on the powder load and bullet design):

.22 Long Rifle (~150 Joules of energy): maybe about fifty.
9x19mm Parabellum (~550 J): perhaps fifteen or so.
.45 ACP (~600 J): a dozen.
5.56x45mm NATO (~1700 J): four or five.
7.62x39mm Soviet (~2000 J): about four.
7.62x51mm NATO (~3300 J): two or three.
12.7x99mm NATO (~18,000 J): none.

Anyway, what kind of Muggle gun are you thinking of using in your story? A handgun of some sort? If so, ignore the last four rounds I supplied above, since they are rifle rounds. A very common and likely pistol round would probably be the 9mm - it's pretty popular these days.

Tim the Enchanter

[Inverarity]

I think a Shield Charm might be able to stop a bullet, but you should avoid treating them like "force fields" or trying to calculate exactly how much "damage" they can take, as if you were playing an RPG. Really bad fan fiction treats spells as numerically quantifiable phenomena. It's good to have a general idea of what a spell's limits are (I could buy a Shield Charm deflecting one bullet, but I'd be skeptical of it bouncing a tank shell or concentrated machine gun fire), but ultimately, what a spell can or cannot do should serve the needs of the story, while remaining internally consistent. (The "consistency" part is something Rowling herself was not always good at.)

[PatronusMagic361]

Yes I think it would. In the last book, Harry uses a shield charm to repel ron and hermione. If it can repel people it can probably repel bullets

[Karaley Dargen]

As with all spells, I also think the power of the Shield would be equivalent to the casting wizard's power. Say, a Shield Charm cast together by Dumbledore and several Aurors/Order members might even block a tank. Probably any trained wizard can block an average bullet, but someone who's in their third year and just learned the concept of Shield Charms won't be able to stop a bullet, but they are probably able to hold human force off.

[Gmariam]

Wow, thanks for all the great responses! Tim, your post blew me away - I hope others can use all that information sometime as well! I have to admit, however, that there is only one bullet fired by a street thug, so I think it's safe to say the Shield Charm will work. No rewrite.

What's interesting is that on the HPL there is also protego horribilis and protego totalum but no real explanation of how exactly they differ from simply protego. Perhaps those spells would stop a tank - or more!

Thanks again!
~Gina

[Tim the Enchanter]

Wow, thanks for all the great responses! Tim, your post blew me away - I hope others can use all that information sometime as well! I have to admit, however, that there is only one bullet fired by a street thug, so I think it's safe to say the Shield Charm will work. No rewrite.

What's interesting is that on the HPL there is also protego horribilis and protego totalum but no real explanation of how exactly they differ from simply protego. Perhaps those spells would stop a tank - or more!

Thanks again!
~Gina

Your welcome, Gina. It was nothing, really - I need to do something with my useless weapons knowledge...

And to answer your questions about the different kinds of Protego...

Protego Horribilis - Flitwick casts this on Hogwarts castle during the final battle. I believe that instead of creating a physical shield of magical energy, it is something that becomes infused into an area and gives off some sort of protection against dark magic.

Protego Totalum - Unlike the normal Protego which casts a shield in just one direction, I believe this spell creates a magic barrier that encompasses a small area, thus the "totalum." Hermione casts this around the tent wherever they go, so I presume it provides some sort of 360 degree protection.

Tim the Enchanter

[A.H.]

Quotes from the HP Wiki:

Protego Horribilis is type of Shield Charm which protects an area against highly Dark Magic.

Protego Totalum was the incantation for the defensive spell used to protect a small area from most other spells for extended periods. It formed a protective "bubble" around the area it was cast in.

The Shield Charm is a spell that creates an energy barrier which deflects minor to moderate hexes. It will not repell any Unforgivable Curse. The incantation for this spell is Protego.

So, otherwise, what Tim said, just with a few more words and different order or words.

/Ari

[Tim the Enchanter]

Normal Shield Charms cannot protect against very powerful curses like Unforgivables. So, what I'm wondering is, what happens to the actual Shield Charm when it hit by something like Avada Kedavra? Does the Killing Curse just pass straight through the shield as if it wasn't there, like some kind of armour-piercing spell? Would the AK punch a hole in it? make the shield explode? Make it dissipate? Turn it into a rubber duck?

Also, Shield Charms don't last forever, and eventually disappear on their own, I suspect. With that in mind, bombardment by hexes and curses would probably hasten the shield's destruction. This leads me to my next question.

Are Shield Charms "fire and forget" spells that are simply erected instantly and sustain themselves, or do you think they require the caster to focus on maintaining the shield's strength? For example, would a wizard assaulted by a constant stream of powerful spells need to concentrate on maintaining his shield, or would he have to constantly cast more and more shields to replace the ones that are overcome by the attacker?

Tim the Enchanter