Not sure about using it in a triumph.

you measure it like any other powder, by volume.

It will be as powerful, and possibly slightly more powerful than 777 powder. I generally use 90 to 100 gr even for elk.

You can't use 777 primers. You have to use the hottest primers you can find. I am currently using CCI 209M (magnum) primers. I have also used Remington STS primers in my Omega.

Hoppes # 9 is the cleaner you should use. Water (what I use for 777) will not work for BH 209.