I not positive but I heard since they banned the 50 BMG in CAL. That they made a 45 out of the bmg cartridge to make it legal also in 55 caliber i think.
It is the Barrett.416.
Specifications:
- Case Capacity 200 grains of powder
- Projectile Solid brass boattail spitzer
- Projectile Weight 400 grains
- Projectile Length 2.0 in.
- Ballistic Coefficient .943
- Cartridge OAL 4.58 in.
- Muzzle Velocity 3250 fps (supersonic past 2500 yds.)
- Accuracy Under 1 MOA
- Barrel Length Choices 32 or 29 in. (81.28 or 73.66 cm)
- Rifle Lengths 50 or 45 in. (127 or 114 cm)
- Weights 25 or 23 lbs. (11 or 10.43 kg)
The .416 Barrett is Ronnie Barrett's answer to California AB 50, legislation that was passed in 2004 which classified all .50 BMG rifles as "Assault Weapons". This required registration of existing guns and prevented new sales and transfers. Barrett refused to repair some Barrett rifles for the LAPD when Los Angeles passed the first ban on his products...
http://www.barrettrifles.com/rifles/rifles_m9916.htm