Stone Demon pearl droprates

I've been farming the stone demon boss a bit on UVH1 trying to get that 3x turtle hopscotch and in my experience the droprate for a handcannon seems way higher than the 0.6% that's listed on lootlemon.

Before this week's patch I tracked 100 kills and got 5 handcannons to drop and today I killed the demon another 40 times and already have 2 more handcannons.

So in my testing that's a 5% drop rate.

What are your experiences with the droprate?