Close-quarter shotgun blasts aren't too frequent, but you'll use this sucker best if you've good aim and are roaming or attacking. Useful anywhere, defence if you have other mates stanmding near, roaming for chasing off the enemy, attacking for Tommygun-strafing the defence and generally killing them. The best weapon of a good player. I'd like to point out my moment of glory when I beat 4 attackers on my own with carefully-placed grenades. And I have a right to be smug, so shut up.
Roamers can use it well, but it's best for defence or escape.
Or rocket launcher to you and me. It's only good in defence with a lot of enemies and attacking, as in narrow areas, you're dead yourself. Defence for causing massive pain and obscuring vision, and torching enemies to death, attacking for disabling the defenders. You need a bind, mate. Also bind keys to . . .