Chris, with all due respect your form is piss poor. Are you trying to get big or just throw heavy weights around? Don't lose sight of your goals dude. If you enjoy the weight throwing more than getting bigger then fair enough, and maybe you should consider olympic weight lifting, you certainly seem to have the knack for it.
Try this form and see how you get on:
Starting from the standing position, a medium width supinated grip as before. Lean over very slightly so that your shoulder are slightly infront of your waist. Keep your elbows in tight to your sides. Lift the barbell. Keep the elbows still tight in at your sides - don't let them drift forward. This will mean the barbell will have to arc around your fixed elbows, rather than the barbell going straight up in a line and your elbows moving out to cater for this as with your previous form. Your movement will end when your biceps and forearms meet, at approximately 70 - 75 degrees - there will still be a lot of resistance and so you will not be able to rest.
Slowly lower the weight, but don't go to full extenstion, keep resistance upon the biceps, probably25 degrees or so. Repeat until failure, possibly followed by drop sets or forced reps if a spotter is available. Let me know how you get on
Think about this: All your biceps know is how hard to tense. They don't even know what exercise you're doing, let alone how much weight you're swinging around.
