Hey guys thought Id share a good routine I've used to pump the guns up. Mine have always responded well to high volume. This may not be traditional for "bulking" but I've always found it smokes every last fibre in those pea shooters:

Grab a training partner
Both set timers to 20seconds
Set a weight you can comfortably do around 10 to 12 reps on a curl machine or triceps rope pulldown. Use smaller weight increments if using plates (ie 25s) so you can drop set.

Partner starts timer, perform deliberate and focused reps until timer runs out. Squeeze at end of movement. Don't even bother counting reps. Your gonna need every last ounce of focus on getting them out soon!
Switch
Rinse and repeat back and forth until you get to 8 sets each, if you can. Your rest period is the 20 seconds your partner is lifting. Goal is to not have to lower the weight and still get a few quality reps till the end. Last set is multiple failure drop set back down the rack (or strip 25s off the machine)

I usually use this to either be standalone quick arm workout tacked onto the end of another body parts day or the end of my arm workout to make sure I can't lift them before I leave! Goodluck!