Although Doom Eternal is lacking an infinite ammo weapon like in Doom (2016), it still has a fully operational Pistol. The player cannot access this weapon without downloading a cheating software and inputting console commands. The reason for the Pistol's exclusion in unknown, especially considering how developed the weapon is.
The pistol in Doom Eternal looks like your standard futuristic sidearm, with a white coat of paint and thin yellow lights adorning it. What looks to be a magazine juts out of the handle.
It uses the same ammo as the Heavy Cannon and the Chaingun, working similarly to that of the Pistol of the original Doom title. It's standard firing mode is a three-round burst, while the secondary firing mode is reminicient of Doom (2016)'s Pistol, in that the camera zooms in slightly and the player can then fire a single, more powerful round in exchange.