bigpappa
I use T7-2f in my inlines and 3f in my sidehammers (loose powder) I do not tamp either of them, I do pour the powder in and tap the die of the rifle down near the breech then i load the projectile. When i seat the projectile i try to set it each time with about the same pressure.
Igniting T7 - does require more heat than regular BP or any of the Pyros... I use Remington 209-4's in the inlines and have never had a problem down to -20 degrees. On the side hammers I use Dynamint Noble #1075+ #11 caps. The are a #11 mag cap - there are just regular #11 caps and i would try to avoid them if possible...
Colder it gets the more difficult to get enough heat to start T7... anything from 32 on up I don't even worry about it.
One of the the things I saw Jim S. do while huntin in the bitter cold of Canada, he laid a hand warmer on the breech are and tied it in place - last most of the day...
I think the most commonly used 209 used to ignite a ML might be a regular Winchester 209...