I always enjoy reading and rereading Guachos writing on the topic of barrel length, it appears he had a definite opinion as per the following excerpt from his writings:
"Some day I hope to test my 34-inch gun for velocity against one having only 28-inch barrels, but whatever may be the result, I for one have yet to find a first-class thoroughly well versed man shooting a double gun with barrels less than 30 inches in length."
His words not mine. I chuckle every time I read that
