Short answer is Remington.
But it is a mix of parts. The action is that of a Remington 700.
http://en.wikipedia.org/wiki/M24_Sniper_Weapon_System
The above is the Army sniper rifle. Gibbs used the Marine m40. In the episode you're referring to, the rifle Ari used was a Bravo 51, chambered in .308 Lapua. This rifle doesn't exist.
There is a Bravo 51, but it is chambered in .338 Lapua. There is no .308 Lapua. The Bravo 51 is named "Kate" and the rifle is only available in .338 Lapua. This platform is available in other calibers, but have different names.
The TV show mixed stuff, but it's just a show.
The .308 caliber (7.62 Military) round has never been called "Kate". I think what you are talking about is a rifle with the nickname Kate. The rifle is a Tactical Operations Bravo - 51. It is a highly accurized version of the marine M-40 and Army M-24 sniper weapons. The weapon is capable of printing .25 MOA or to the non-shooters out there, can but bullets in 1/4 inch groups for every 100 yards in distance. EX: If a TRAINED sniper shoots a target 400 yards down range the rifle is capable of putting all rounds in a 1 inch group, 2 inches @ 800 Yards etc. out to 1000 yards. As with most things, you get what you pay for and the rifle is very expensive and is usually found in Police SWAT and some military Spec. Ops. Units. As far as I can determine the name "Kate" was given to one weapon, the operator of the Sniper Central website was a military sniper and had named his rifle "Kate". When he left the service and had to give up "Kate" he purchased a Bravo-51 and called it KATE II and mentioned it on his website. It took off from there. It is common for rifle shooters to name their rifles. Daniel Boone called his "Tick Licker" for instance although most name them after women. Hollywood is responsible for people thinking all .308's or that there is a Kate model out there because when they killed off the character Kate in the NCIS episode "Kill Ari" Gibbs said snipers who used a Bravo-51 called them "Kate". The Gibbs character was a sniper in the Marine Corps. Hope that helps. Here is what a Bravo 51 looks like: see link below-
Special Agent Kate Todd is shot by a sniper and killed on the season 2 finale of NCIS.
Kate Middleton was given the title "Duchess of Cambridge."
Kate O'Hearn was born in Toronto, Canada. Kate is best known for the Pegasus series of books.
Not much is known about Kate Gosselin's parents other than they are alive and Kate does not have much of a relationship with them. Kate also has siblings.
The answer is simple, Kate Mulgrew is best known for playing Captain Kathryn Janeway on Star Trek: Voyager. Other than that, there is no special information on Kate Mulgrew.
Mary-kate:Torquise (soon to be known Mary-kate) Ashley:Violetpink
Kate Middleton will be known as Her Royal Highness the Duchess of Cambridge.
Yes, Kate Ceberano does have one child. She has a daughter named Gypsy Rogers. Kate is a well known Australian singer.
Sniper shot her, because she got too close to catch person (aka Dragon) that ordered hit on her mother.
Kate Middleton will be known as Her Royal Highness the Duchess of Cambridge.The Duchess of Cambridge
Because she does not come from the aristocracy, she is not known as Princess Kate (although many people will call her that anyway). She has been given the title Duchess of Cambridge, and those who address her will undoubtedly refer to her politely as "My Lady."