The Lyman 310 tool, with it's small dies, was the first loading tool for a great many hand loaders. I never owned one, but the first hand loads I ever shot were made on a friends 310 tool.
As late as the 1970s one match shooter I knew loaded all his ammunition for the matches with a 310 tool.
At that time the Rifleman's Rodeo was very popular at Salmon Arm, BC., attracting around 100 shooters. One of the regular shooters was the Park Warden at Wells Gray Park and he was also a major winner at some of the various events. I forget what calibre rifle he had, but it was likely some type of 6mm.
He would come to the shoot with enough ammunition to do him for the first day. That evening he would sit at a picnic table by the camp fire and load his ammunition for the next day, maybe 40 or 50 rounds, using his Lyman 310 tool, along with a powder measure.
On top of that, he was a great story teller and during the entire time that he was loading his ammunition, he told stories for all of us at the evening get together!
Bruce