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air gun
Posted: Fri Nov 02, 2012 10:47 am
by cptspecialbrew
hi there
always wanted a gunpower stealth for getting rid of vermin where i work,but the only thing putting me off is the confusing amounts of ways to get it to fac level,
i currently have a ruger 10/22 but obviously im restricted to shooting clubs and cant be blasting that around work,
if i was to pay this kind of money for an air rifle i would like the option to convert it to fac (and ive heard the stealth is the easiest),
i have done some digging and asked a few guys at the gun club and they seem to think you can change the power of the gun just by changing the valve,
if this is true what do they call the valve and where would i get one
cheers
Posted: Fri Nov 02, 2012 11:11 am
by jackssmirkingrevenge
If you want to take it to FAC levels without actually applying for one, be aware of the legal implications if you're caught.
On a technical level, the best place to go is Bob Craske's site:
http://www.stealthresource.org/
The Stealth range of Rifles employs a highly efficient air system that can easily produce quite stunning power levels without wasting air or losing accuracy. It is simple, robust and reliable – sheer genius! However, the excellent rifle design appears to have been conceived in America and with a somewhat higher velocity than the UK legal 12fpe in mind.
The mechanism in the UK rifles appears to have been ‘throttled back’ in order to reduce power for the restricted British market. This has led to some compromisation of the original design and thrown up a few problems in the process - just for good measure!
The Hammer seems to be somewhat lightweight for the job intended, that of reliably striking the valve with the same force every time. It has been found that the plastic Hammer can chatter in a dry rifle and thus bleed off a substantial amount of its energy before it reaches the firing valve.
The Hammer spring seems to be rather weak for reliably propelling the Hammer into the valve in a consistent manner and exacerbates the problem above.
The firing valve return spring, which is fitted inside the valve assembly and inside the air reservoir, is, for some reason, of very heavy gauge wire. It is difficult to see why this is necessary when its primary function is simply to hold the valve shut in an empty reservoir prior to filling. Once filled, the air pressure, at nearly 3000psi, is more than adequate to shut the valve with remarkable alacrity!
This means that the Hammer, in order to open the firing valve, has to overcome its own sliding friction, its own inertia, the inertia of the Breech Slide, the friction of the front Breech Slide ‘O’ ring on the barrel, the air pressure inside the reservoir and also overcome the massively heavy valve spring before any valve movement can take place.
On many UK Stealth Rifles therefore, by the time the Hammer has reached the point of actually opening the air valve, a substantial amount of its initial energy has already been dissipated, often in a variable manner. As a result, valve strike varies from shot to shot and velocity consistency suffers with a resultant effect on accuracy.
Posted: Fri Nov 02, 2012 11:27 am
by Gippeto
Would suggest you post any questions over on the TAG. Bunch of good guys with loads of knowledge regarding that platform. Quite a few with knowledge of your local laws as well.
http://www.talonairgun.com/forum/