BB Weight Guide — Choosing the Right Weight

BB weight is the easiest variable that shapes your airsoft performance. The same gun behaves very differently depending on the weight you feed it. The core principle is simple — the energy your gun delivers to the BB is roughly constant, so heavier BBs fly slower (E = ½mv²) but gain momentum and trajectory stability.

Quick reference

Weight	Characteristics	Typical use
0.20g	Highest velocity, easily pushed by wind, wobbly flight	Indoor CQB, low-power AEGs, chrono reference
0.25g	Balanced speed and stability	Outdoor starter, general purpose
0.28g	Less wind drift, tighter groupings	The outdoor AEG standard
0.30–0.32g	Heavy, consistent flight, better retained energy	High-power AEGs, entry DMR
0.36–0.40g	Slow but very stable, better brush penetration	DMR, bolt-action snipers
0.43–0.48g	Lowest velocity, maximum stability	High-power sniper rifles only

Why do heavier BBs hit more?

First, they resist wind and disturbances. At equal energy a heavy BB flies slower but carries more momentum (mv), so crosswind pushes it less. Second, they lose speed more gradually. The fraction of energy lost to drag is smaller, so impact energy stays higher downrange. Third, backspin stays more consistent, reducing the erratic rise ("fliers") at the end of the trajectory.

How much FPS do I lose going heavier?

At constant energy, velocity scales with the inverse square root of mass: v₂ = v₁·√(m₁/m₂). A gun shooting 328 fps on 0.20g (~1 J) shoots about 277 fps on 0.28g — but the energy is still exactly 1 J. Since most field limits are energy-based, switching to heavier BBs does not violate a joule limit (though some fields set per-weight FPS caps — check local rules).

Choosing in practice

Indoor / CQB (≤1 J): 0.20–0.25g
Outdoor AEG (1–1.2 J): 0.25–0.30g
DMR (~1.5 J): 0.32–0.40g
Bolt-action sniper (2 J+): 0.40–0.48g

Curious about equivalent FPS and range for each weight at your gun's energy? Use the weight comparison table in the ballistics calculator.