Does 1/4 inch make a huge difference??

[Booga22]

Hello!! I'm after a bi of advice re sizing of bits. Looking at a few KK bits on good old ebay, and there seems to be a distinct lack of 14mm bits to choose from. There are either 5.5" 16mm, or 5 3/4" 14mm.
So, the point I'm gettin at, slowly, is, would going up 1/4" make a huge difference, or should I just persevere and buy a 5.5", even if it means going new??

 

[Buzz1]

if it is too big when you get it put bit rings on

 

[Divasmum]

One problem with putting biscuits on is that if you want to do dressage they are not allowed.

 

[lindsayH]

 

[Booga22]

Think I'm going to have to buy a new one - much more money!!! She currently wears a 5.5", and has a broad, fleshy mouth but I just don't know whether I should just go for it, and if it's wrong, sell on, or play by the book....never simple is it!!