It's the 98DAC compact that takes BHP magazines. The 98DA (no "C") full-size takes proprietary mags.
I am not an expert on the Arcus 98-series nor the BHP, but it's my understanding that the designs share little in common other than the magazine in the DAC compact.
"Smokey, this is not 'Nam. This is bowling. There are rules... MARK IT ZERO!!" - Walter Sobchak