How to remove a stubborn axle hub?

I have a 1964 Jeep Cj5 with a Dana 44 rear axle. This is the older rear axle with the keyed end. The nut is removed and I am using a axle puller attached to the lug studs to pull on the hub. NO MOVEMENT! tried heat, tried smacking the puller with a small sledge hammer. how much heat can be used? ho hard can the hammer be swung? any advice would be great