The distance unit (DU) is a unit of measurement in Splatoon and Splatoon 2. It is used to measure distance internally in the game. There are always 50 distance units between each distance line in the Shooting Range. In Splatoon 3, the internal values are displayed as a tenth of a DU.
The range of each main weapon, measured in DU, can be found at main weapon data.
In Splatoon 3, the internal values are a tenth of a distance unit, so the interval between two lines in the Shooting Range is displayed as 5.0 internally in Splatoon 3, instead of 50. The Japanese unofficially call this new unit "meter", and regard the Shooting Range intervals as 5 meters apart. 
The Bamboozler has a default range of 195.64 DU when fully charged. Since each line in the Shooting Range is 50 units apart, a Bamboozler can damage Squid Bumpers in the Shooting Range up from about 4 lines away (