In "Resurrection" (S07E01), Ron Saris (Kim Coates) pulls a Glock 17 on Detective Yelina Salas (Sofia Milos). He later uses the same gun to shoot at horatio at the climax of the episode.
In "Gone Baby Gone" (S07E08), Rodrigo Sanchez (Mario Prado Jr.) pulls a Glock 17 after crashing his car while being chased by Horatio.
Calleigh Duquesne (Emily Procter) continutes to use a Kimber Pro Carry II pistol during season 7. In "Target Specific" (S07E19), a Russian mobster holds Calleigh at gun point with her own pistol. Later in that same episode she is seen using a black version of the same gun since the mobster still has her original.
In "Gone Baby Gone" (S07E08), Wolf finds a Smith & Wesson Model 66 that was used by one of the kidnappers to kill her partner. It is identified as a ".357".
In "Dissolved" (S07E24), a deranged and delusional Julia Winston (Elizabeth Berkley) comes into autopsy with an unknown revolver.
Shotguns
Remington 870
In "Head Case" (S07E12), Kurt Sabin (Brian White) is seen with a sawed-off Remington 870 which he uses to force a handyman to kill.
Submachine Guns
MAC-10
In "Resurrection" (S07E01), members of the Crypt Kings gang stage an attack on an armored car using MAC-10s. The guns are loaded with a special type of armor-piercing ammo (called "fused alloy") which is stated as being able to harden when sensing armor and shatter in flesh.
Assault Rifles
APS Amphibious Rifle
In "Sink or Swim" (S07E16), Ken Vogel (Johnny Messner) uses what appears to be a customized AK-47 that is possibly supposed to be an APS Amphibious Rifle to kill Derek Powell's wife. The weapon fires a dart that is approximately 5 inches long. Calleigh describes the dart as a drag stabilized projectile that is designed for use with an underwater assault rifle.
Colt M4A1
In "Gone Baby Gone" (S07E08), Miami Dade SWAT officers are seen armed with a Colt M4A1s.
Sniper Rifles
Ruger 10/22
In "Resurrection" (S07E01), Evan Caldwell (David Keith) uses a Ruger 10/22 to fake Horatio's death. The gun is used to shoot a squib on Horatio's chest, over his bullet proof vest.
Heavy Weapons
In "Collateral Damage" (S07E23), a pair of homemade Mk 2 hand grenades are used to kill a family as they were eating at a restaurant. The killer equiped them with a home-made fuse using a converted camera flash. One of the grenades fails to detonate and ends up in the clothing of one of the victims. Later, in autopsy, it falls out of the clothing and the spoon comes off, the resulting blast heavily damaging autopsy and nearly catching Ryan Wolfe and Kyle Harmon, the latter volunteering at the crime lab at the time.
Collections
Gun Bag
In "Resurrection" (S07E01), a bag of confiscated guns is containing a Ruger KP90, a M1911A1 and a MAC-10.
Gang Guns
In "Tipping Point" (S07E11), a collection of guns is seen in a box which Hector Salazar (Jon Seda) had confiscated from his former gang.