Someone came by searching for “what were guns like in 1910.”
If we confine ourselves to sporting firearms, there were far fewer semi-automatic firearms of any sort.
Wingshooters generally preferred the double barreled shotgun, and some even preferred the “damascus barreled” doubles that were grandad’s pride and joy. Most, however, turned to the new “fluid steel” barrels that improvements in steel making had made possible. Slide action shotguns, typified by Winchesters Model 1897, were becoming increasingly popular.
The “turnbolt” action, the sort we ordinarily call bolt action, was beginning to edge out the lever action and the single shot rifles that had been the mainstay of American hunters and target shooters since 1865. Of course, the military’s “brand new model of 1906” Springfield with its “thutty ought six cattridge” was not available to civilian hunters, but Mauser actions and Mauser copies were available. As were Krags, and other bolt action rifles.
In handguns, there were quite a few small caliber semi-automatic pistols available; as well as a small number of big bore semis, but the most popular handguns were double action revolvers. Those were available from many makers, including Colt, Smith and Wesson, Hopkins and Allen, and dozens more. Of course, the single action revolver still gave the double action revolver a run for its money, but the outcome was plain. The “pull the trigger to cock and fire the revolver” double action was the wave of the future.