400 Nitro,
Thanks for the info. The caliber, "500-450", is stamped on each barrel bottom just forward of "B. Blindee" and "11.1". Nowhere on the rifle is a maker identified, unless its the two guys with shields in a circle on the barrel flats. BTW, the chambers differ from the Brit 500-450. The shoulders are sharper and a bit further forward. Case length seems to be 3 1/4". I've been shooting 480gr cast GC bullets sized to .452. Decided by the fast twist to try heavier bullets. I've considered trying the Barnes bullets made for the 460 S&W since they measure .451, but hear all the bad stuff about X bullets in a DR. This is a "best" gun...SLE, hinged front trigger, full coverage rose and scroll, stunning wood...why wouldn't a maker want his name on it?

Otto