9 damage, 10 shots/sec full-auto. The Rattler doesn't excel at anything but it doesn't fail at anything either. Moderate pen, decent range (56.2), reasonable DPS (299.7). It's the gun you find in a container and use because you have nothing better.
// SHOTS TO KILL (PVP)
Shield
Body
Head
None
12
5
Light (Green)
19
8
Medium (Blue)
20
8
Heavy (Purple)
24
10
// THE MATH
Magazine scaling: Mag grows from 10 (I) to 16 (IV). That's a 60% increase. Upgrading Rattler gives you meaningful sustained fire improvements.
// VERDICT
Workhorse AR. Not exciting, not bad. Use it when it's what you've got.