Im a real slacker when it comes to changing buckets.
I dont secondary, I dont use a bottling bucket, for that reason I dont bulk prime, I dont want to stirr up sediment in my primary.
So, I prime bottles individually. The most sugar ive ever used was 1 teaspoon per 330ml bottle. I forgot it actually should be approximatly 1 teaspoon per 500ml bottle, which I "normally" use. So those ones were quite over carbed.
Basiocally you open them and they run over the top like a warm bottle of champagne. You may as well drink straight from the bottle cause if you poor into a glass you get nothing but head and the yeast on the bottom is pushed around the moment you pop it so eh, no harm no foul.
So, i guess thats a gusher. But you dont lose more than 1/6 of the bottle when opening.