A word about power.
Although this is mentioned elsewhere on the site, this is worthy of repetition again, as it cannot be emphasised enough.
The Stealth can be great fun to tinker with, in the search for perfection and the Holy Grail of maximum air efficiency, minimum lock time, and maximum consistency, which of course equals accuracy.
You must bear in mind though that fitting any new part that is involved in the firing cycle, can change the characteristics of your gun. Specifically the muzzle velocity of projectiles may change, with possible legal implications.
You are responsible for your actions.
Owning an air rifle in the UK , producing over 12 foot pounds muzzle energy, is a criminal offence if it is not listed and held on the owner's firearm certificate.
This offence carries a mandatory penalty of five years imprisonment under the Criminal Justice Act 2003.
The word "mandatory" here, means that the Judge is afforded no latitude or discretion in passing sentence. You will go to prison.
For people thinking of converting their gun to a legally held firearm, please remember it is illegal in the UK to modify any air gun so that the muzzle energy is in excess of 12 foot pounds unless you have your FAC amended to list this item, prior to the alteration of the gun.
It is not my intention or purpose in life to assist people in breaking the law.
If you're after only power for the sake of it, and intend to own an illegal firearm on the off-chance you won't get caught, please desist! It is more than foolishness, it is utter stupidity, and if you want to pursue this course, please don't ask for my help, as I will refuse.