Ive got a mule with a tiny mouth. Her ideal bit size is a 4 1/2 but I just recently rode her in a 5in that I liked. It was a medium port with a roller and had lose calavary shanks.. 8in I think. I've been looking for a similar one in 4 1/2 but found that they are nearly impossible to find. She was started in a snafel and then went to a pelham, and is currently in a lose shanked tom thumb. She seems to go fine in the 5in so im tempted to leave it. No gaping or carrying her head funny, she seems to like the bit. I figure If it aint broke don't fix it, right? From this point on shell spend the majority of her time in either this bit or the tom thumb, so im just wondering if the bit being a little big will hurt, or if theres a place to find a similar one. Thanks!