pumping up a theoben......

lucy333springer

eliminator, what pump, where can i purchase one, and how do i know how

much pressure to

pump it up to, seems to be tight enough on the break barrel,

but for futher reference, id like to know how

thanx 333.

milkerman

The so called 'gas ram' used in the Eliminator & HW90 is pumped to operating pressure by the manufacturer. They are known to leak though, rare but it does happen. The type of pump used is a high pressure stirrup pump. AFAIK a stirrup pump doesn't constitute a part of a firearm so you should be able to get one in from the UK or rest of EU. The fitting for the gas ram can be had from Theoben (that might be a firearm component).
If I remember rightly, the exact pressure is determined by experimentation- you will need a chronograph. Starting from a low pressure the velocity of the pellet will increase as you up the pressure, you also need to monitor how the rifle's accuracy is performing. The correct pressure is arrived at when you have good velocity combined with accuracy. Go too high on the velocity and the pellets will group like a shotgun. Theoben have/had a good website, take a look at it and perhaps email to get max pressure figure & advice.
A word of caution; These stirrup pumps look innocent but can pump up to about 200 atmospheres into a pressure vessel. YOU WILL DISRESPECT 200 BAR ONLY ONCE!