probs, almost definetely, actually.
marking at almost any internal exam is usually harsher. atleast thats what most my teachers say.
while internal exams will have certain levels of bias, and frustation of hours of unpaid labour, markers get paid for the marking they do after their full time hours for externals. you can't blame the teachers not wanting to mark hundreds of papers... they have families, lives and things they want to do.
the ethos that goes towards external marking also seems to be different; it's all about how much marks they can give you, not how many they can take away.
maybe i'm just spewing lies, but that's what i've heard.