At first glance the watch at the base of the barrel could be mistaken for a pocket watch, but upon inspection it gives off a strange blue glow and carries only one hand. Holding the rifle, honing in the sight and becoming comfortable with it gives a strange sense of time. Reloading seems to take no time at all, and yet when tryign to hit a moving target time seems to slow. the runes on the barrel are Draconic numerals, starting at one and ending at twelve. 

It’s up to you to decide whether a character has proficiency with a firearm. Characters in most D&D worlds wouldn’t have such proficiency. During their downtime, characters can use the training rules in the Player’s Handbook to acquire proficiency, assuming that they have enough ammunition to keep the weapons working while mastering their use.

Notes: Damage: Piercing, Upon shooting a rifle the watch hand spins, In general it always lands on one, however, with a natural one or a critical hit the hand lands on a random number. Roll a d 12 and follow the table below: Time Warp Table 1-Normal shot 2-Haste 3-Haste on all allied party members 4-Misty step to a location you choose 5-Teleport 100 feet in the direction you are facing 6-You Teleport to your closest party member 7-Teleport one enemy to a location you choose 8-all allied party members are slowed 9-Teleport to a random location (DM's Choice) 10- Do max damage to an enemy 11-you shoot a second bullet, roll for damage and roll for Time Warp again. 12-Phase to a different time line, You spend several hours with this rifle, honing in the sight and practicing shots. It becomes second nature to use., Range, Two-Handed, Ammunition (Firearms), Reload, Slow