Flash/Vectis power adjustment issue Help.....

[stevensuf]

HI Folks,

I know this is a mostly US site, but hope you guys can help.

I bought a Vectis from a company in Spain, Their the power limit is approximately 18 FPE.

I am Scottish and live in Portugal where the limit is 1125 fps in 022 so was trying to adjust

the power.. I have played with the hammer spring with little change.



I bought a cheap chrono on ebay, but I am unsure of its accuracy.



I have an older HW97K that I have had for years, it tested at 550 fps approx 9.6 FPE, which i thought

was a bit low, it used to power around 13fpe but has layen unused for over a decade.



The Vectis has chronoed around 650 FPS, making around 14fpe, this was after fiddling with the hammer

spring for best power.



I am wondering if the chrono is out, ie not accurate or both guns are down on their stated power.



I have pulled the vectis to pieces and can find nothing wrong, some area in Europe have laws,

which state that PCP rilfes should be made difficult to change power, so I am also wondering

If there was something done to the rifle to limit its power output.



The hammer spring had 2 shims fitted, max power was probably about half way from front to rear.

I have opened the rile up and the transfer port looks the same spec as US models around 3.5mm.



I dont know if the chrono is inaccurate or if there is some other method to reduce the power other

than the hammer spring?



Any help is appreciated.

Many thanks

 

[Peep]

Check if the hammer spring has had a coil or two removed, it will not have a flat end on both sides if it has been shortened. I have three factory spacers in my Vectis with a shortened barrel. Power kept going up with increasing preload. Now at 840fps. 

 

[stevensuf]

HI

Have checked the spring, it appears untouched, i also found a 3rd spacer in the hammer that I had not noticed when disassembling. the other 2 were behind the spring inside the retainer type thingy. I cranked the spring so hard the rifle would not cock with a drop to around 550 fps, best was about 5 to 6 turns back in from fully out at around 660 fps, nb this is a .22 caliber.

 

[Peep]

By any chance has the barrel ever been removed?

 

[Odoyle]

Try filling or shooting it starting 130 bar (1900psi) and see what speed it clocks at that pressure. When adjusting the power.

If that helps try gradually increasing start fill pressure and chrony until you find the starting sweet spot that won't give you valve lock.

 

[Recondo2142]

Check out AIRGUNNERS EDGE channel on YouTube.he has done some power mod's for the Hatsan flash,flashpup.I have 6 flashpup's my .25 cal can push the JSB'S 33.95 gr mk2 pellets in the 840's fps on the high side then at the end of a 10 shot magazine still above 800 fps.get a crony if you really want to tune your PCP'S.I use the FX chronograph.

 

[stevensuf]

Peep,

Thanks, yes I think the rifle has been a return and resent out, when i stripped it i noticed the screw for letting the air out was burred and the nut that holds the barrel shroud in place was loose, also everything came apart very easily and there were marks where a scope had been. I did notice someone else said when their barrel was not aligned properly it lost lots of power. I really should return it, but from here to spain is a pain in the.....

Sweet

I will try that upon reassembly.

Reconodo

I did buy a chrono, but cheap chinese job and to be honest I am not sure of its accuracy..

 

[stevensuf]

Odoyle

Can you tel me what you mean by valve lock? I am still a novice to modifying and tuning.



Thanks

 

[Odoyle]

If the unregulated gun is set for low power it usually doesn't have enough hammer spring tension to knock the valve open when filled to high pressure. You need to start at lower pressure. High pressure will usually start real slow if filled to the max. You read very slow chrony if filled high pressure till pressure drops to the sweet balanced lower pressure spot. You wasted a lot of lower power shots by then. Start low pressure then chrony then gradually fill higher shoot over chrony till you see that start fill pressure lowers the velocity then you know what fill pressure to start from each time you refill the air.

 

[stevensuf]

Thanks O doyle.



I think i understand now, so if the hammer spring is too weak and the pressure too high in the bottle ,then the hammer wont open it up much

and the shot will be low powered. As the pressure comes down the hammer will open it more to allow more air flow for a higher powered shot.



Peep

I am begging to think you are onto something the with misaligned barrel, as the air per shot increased with the hammer adjustment, just not much more

power, the air had to be going somewhere also the noise went up considerably.



To the tuners out there, is it worth opening up the port on barrel a bit before reassembling?

Also the port on the bottle, should that be enlarged?

 

[Peep]

On my Vectis the barrel had to be set out from the shoulder a little to get the ports in alinement. Instant 100fps when everything lines up. Hope this applies to your gun.

 

[Peep]

Be carful, the set screws holding the barrel are working in a plastic receiver, easy to strip. If you do strip the threads you can tap the next larger size.

 

[stevensuf]

Thanks peep, when I reassemble I will use a rod or something , though the access screw for the transfer port to make sure the barrel is 100 percent aligned, I will

make a mark or something for the air cylinder port alignment also.

 

[stevensuf]

Ps it was the valve stem that was the issue, hatsan put a thicker valve stem on some european models, which limits airflow and thus power.

 

[Fatmike]

Could your gun be a low fps version. The valves are usually different and you can get the full power versions from hatsan . Duh I skipped ahead and didnt read the last reply.