6.8mm and PRA rifle rebalance (#22089)

Rebalances the 6.8mm bullet and it's AP variant to not be antag shredder
9000. Additionally, alters pricing in the cargo order list and adds an
AP variant of the 6.8mm to the cargo order list. The values for the
rounds are below.

6.8mm: 40 dam | 12 AP
6.8mm AP: 30 dam | 30 AP

Against 55 armor (major ballistics armor):
6.8mm: 13 damage
6.8mm AP: 18 damage
5.56: 16.67 Damage
5.56 AP: 25 Damage
7.62: 18.56 Damage

The thought process behind these values:
<details><summary></summary>
<p>
Adhomai does not make wide use of personal body armor. As a result,
ammunition does not prioritize defeating body armor. Therefore, it is
more effective the less armor one has, leading to a high damage value
but low AP values. As they are rifle power cartridges, there is still
some AP. The specific 6.8mm AP cartridge was created for defeating the
armor of the S'rand'marr coalition, thus why it is comparable to 7.62
</p>
</details> 

These values can be tweaked as needed to make the rifle and ammo
reasonable.
This PR DOES NOT modify the rifle itself, and therefore should not
conflict with #22088

code/modules/cargo/items/weaponry.dm

@@ -200,7 +200,7 @@
 	name = "Tsarrayut'yan automatic rifle"
 	supplier = "zharkov"
 	description = "An Adhomian assault rifle from the People's Republic of Adhomai."
-	price = 1450
+	price = 1650
 	items = list(
 		/obj/item/gun/projectile/automatic/rifle/adhomian
 	)
@@ -436,6 +436,20 @@
 	spawn_amount = 1
 
 /singleton/cargo_item/magazine_68ap
+	category = "weaponry"
+	name = "rifle magazine (6.8mm AP)"
+	supplier = "zharkov"
+	description = "An AP 6.8mm rifle magazine."
+	price = 80
+	items = list(
+		/obj/item/ammo_magazine/a68/ap
+	)
+	access = ACCESS_SECURITY
+	container_type = "crate"
+	groupable = TRUE
+	spawn_amount = 1
+
+/singleton/cargo_item/magazine_68sniper
 	category = "weaponry"
 	name = "sniper rifle magazine (6.8mm AP)"
 	supplier = "zharkov"

code/modules/projectiles/ammunition/boxes.dm

@@ -593,6 +593,10 @@ If nothing is chosen, reload sounds revert to the default, which is metal_slide_
 /obj/item/ammo_magazine/a68/empty
 	initial_ammo = 0
 
+/obj/item/ammo_magazine/a68/ap
+	name = "magazine (6.8mm AP)"
+	ammo_type = /obj/item/ammo_casing/a68/ap
+
 /obj/item/ammo_magazine/a68/hotaki
 	icon_state = "SVD"
 	ammo_type = /obj/item/ammo_casing/a68/ap

code/modules/projectiles/ammunition/bullets.dm

@@ -541,7 +541,7 @@
 	icon_state = "rifle-casing"
 	spent_icon = "rifle-casing-spent"
 	caliber = ".599 Kumar Super"
-	projectile_type = /obj/projectile/bullet
+	projectile_type = /obj/projectile/bullet/rifle/kumar_super
 	max_stack = 5
 
 /obj/item/ammo_casing/c6mm

code/modules/projectiles/projectile/bullets.dm

@@ -303,13 +303,13 @@
 	penetrating = FALSE
 
 /obj/projectile/bullet/rifle/a68
-	name = "R33 Tamparii bullet"
+	name = "Z33 Tamparii bullet"
 	damage = 40
-	armor_penetration = 17
+	armor_penetration = 12
 	penetrating = FALSE
 
 /obj/projectile/bullet/rifle/a68/ap
-	name = "R33s Tamparii bullet"
+	name = "Z33s Tamparii bullet"
 	damage = 30
 	armor_penetration = 30
 	penetrating = TRUE
@@ -324,7 +324,7 @@
 	maim_rate = 3
 	anti_materiel_potential = 2
 
-/obj/projectile/rifle/kumar_super
+/obj/projectile/bullet/rifle/kumar_super
 	damage = 40
 	armor_penetration = 30
 	penetrating = TRUE