Sounds like you have a very light load to me, any powder is gonna burn poor at low charge. Even the 5 gr disc is to low to me for a plated bullet.

Where did you get your load data?

Alliant has a Max load of 6gr for a 240 LEAD bullet.

The discs on the Lee are only a "guesstimate" you need to use a scale and get the EXACT weight of the charge

I myself would not use BE in a 44 Mag but some folks do. It is a fast powder.
Any LPP will work it's not the primer. BE is not the "cleanest" of powders to begin with.


Just my 2 cents

__________________
Still Running Against the Wind