The predominate barrel length for SC shooters in the US (using OU's) is 32".
30" is likely the predominate barrel length for those shooting autoloaders. I've noted that 30" barrel OU's may be more popular in the UK for SC's based on the guns offered for sale....I can't validate that 'cause I've never been across the pond. I have shot numerous tourneys in the US and know what's being used.Yes, I shoot a heavy 32" gun and furthermore I'd like to try a 34". cool

Dodging lions and wasting time.....