Editing Mac 1 Annihilator (section)

== Design ==

The Annihilator was built around a Sheridan-type stacked-tube action. Documented base markers included the [[PMI-1]], [[PMI-2]] and [[Sheridan PGP]].[3] Its principal features included:

* a lengthened, honed barrel;
* a centre-fire bolt;
* a Delrin anti-blowback pump;
* a direct or positive gravity-feed system;
* a scope or sight rail; and
* either 12-gram CO2 operation, constant air, or a configuration capable of accepting both.[1][2]

McMurray & Son initially experimented with feed tubes held by set screws, but found that the screws could deform the tube. A friction-fit feed arrangement was subsequently adopted. Constant-air development was informed by feedback from players, particularly Bob Mariotti and the [[Wolf Pack (paintball team)|Wolf Pack]].[1]

Because each Annihilator was a customised marker, specifications varied. A basic model photographed in 1987 had a 12½-inch precision-honed barrel, three-inch Delrin pump, positive feed and sight rail. A more extensively equipped example had a five-inch pump, side-air fitting, 10-ounce constant-air bottle, shoulder stock, Herrett grips and an Armson OEG sight.[1]