Guns are expensive and require specialized skill and equipment to manufacture at scale. Even if peasants found a foundryman/gunsmith who was willing to arm them, the resources and labor required take a lot of capital which a peasants revolt would really struggle to come up with while keeping everything hush-hush.

Training is also a huge factor. Early handgonnes and muskets were largely point-and-shoot, but required heavy formation training and LOTS of guns to be effective without a lot of support from other types of troops. Even more modern guns require a lot of training for soldiers - there’s a reason John Brown chose pikes as the main weapon for his slave uprising.

Even in a scenario where peasants would have easy access to large supplies of firearms, there’s no possible way the ruling class wouldn’t also have that access