booster well

booster well

[′büs·tər ‚wel]
(ordnance)
A hollow space, in the main explosive charge of an item of ammunition, into which the booster fits.
References in periodicals archive ?
Booster Wells said: "I thought I was the worst gater in the Elite League and probably the Premier League as well, but we finally got something worked out with the clutch and I ended up in front.