"New" is relative, it could have been new, but old stock, those made prior to 2007 were overbore and wouldn't shoot .429"-.430" bullets well at all, but yours sounds like a new SB1 44mag with a tight bore since it has the late style stock. Barrel markings are irrelevent to the frame type, almost all H&R centerfire rifle barrels are marked SB2 even tho they come on SB1 frames. The late model 44mags normally shoot good, did you read the Handi Basics 101 yet? Oil on the latch and/or shelf will destroy any hopes of accuracy. The serial number prefix on the frame determines year of manufacture, yours is probably CAC######, made May 2008 or later.
Tim