Mk1 Rapid tuning

[LSS]

Got a Mk1 Rapid which was initially just leaking.
Had a look inside to find the hammer spring had been shimmed and so the hammer had deformed the valve face. Managed to sort that issue but upon testing velocity, found the power curve to be so that the velocity crept over 12ftlb. I can reduce the velocity no problem but is there a way of stabilizing the power curve on these as their non regulated ?
Heard and been told many different "solutions" but not overly convinced by many of them.
Any help appreciated   

[angrybear]

Make sure the barrel port is sub 12 size, replace the valve assy with a smaller bore sub 12 one, these reduce the air flow to stabilise the power.
or a shorter, softer spring so the valve is open for a shorter time.

[Ca_Varminter]

KevG the Rapid Doctor should Chime in on this......
There is many variables that has the cause and effect...
The best solution for a sub 12fpe Rapid is a KevG Regulator....
This will help even out flatten the velocity curve... All the while keeping it legal!

Good Luck,
Stuart

[KevG]

if the gun is running right it
should be doing around 11 ftlbs when filled to 170/180 bar increasing to around 11.7 ftlbs when bottle pressure drops.if power curve is much worse than this all the ports need checking.what calibre is it.
kevG

[LSS]

Hi Kev

The power curve was surprisingly good for a non regulated rifle. Over the course of 30 shots, starting at around 200BAR the velocity went from 11.25 ftlb to 12.05ftlb, spread of 7.1 MPS. This is the first time working on one of these rifles so was pleasantly surprised. Ideally would like for the velocity to be more stable but from what I understand there isn't a regulator for the Mk1 ?

Im pretty sure the rifle is completely standard, and apart from the shims found on the hammer spring nothing else has been played with.

Its a 5.5mm

[KevG]

it will go even higher after more shots.best way is fill to around 130/140 bar and set power to around 11.7 ftlbs.then start testing for best fill pressure for that individual gun,it also depends what power curve you can live with.
kevG

[LSS]

Ideally I would like to get the rifle to a point where it can be filled to say 190 bar and shoot consistently throughout as much of the pressure range as possible.
Do you make regulators for these ?
Happy to discuss over PM 👍

[KevG]

yes do a dedicated reg for the old mk1,more or less doubles shot count with no power curve.
kevG

[LSS]

Hi Kev

Sorry have been away working.

How do I go about getting hold of one of your regs ?

[KevG]

just send me a pm with your number and can give you a ring m8
kevG

[LSS]

Hi Kev

Not to sound daft but how do I send a PM, cant see the option lol

[KevG]

I've emailed you my number m8
kevG