I have a Firehawk and tried the conversion, my advice -don't
I have gone around the block with my Firehawk (which I will never sell in case need to hunt in Washington state, -great gun!!!). Here is my experience; changed from #11s to musket caps for no good reason, had problems with musket caps falling off and leakage through caps' split sidewall in wet weather. Then I converted to 209 and had even worst problems with my charge getting wet. The 209 'nipple' replacement has big gaps in 4 places apparently to relieve pressure. These are wide enought for a finishing nail to fit in, which is how I used to remove it. They also are open to the flash hole with a primer on so rain, snow etc gets in. I tried the T/C breech cover (N.G., didn't seal) and the best solution was Gorrilla duct tape. But I asked why go through the hassle, mag CCI #11 were more accurate and never failed to fire (and ML season is Dec up in VT, I shot a doe one day at -9 degrees F). They form the best seal by far and you can buy plastic tubing seals that give even more insurance. I really advise against it if there is any dampness where you plan to hunt, I missed a nice buck because of it and had another 'poop' fire clearing my gun at the end of a day where my bullet bounced across the sand 30 ft in front of me when i was aiming at a rock 60 yds away.
