20 cal rapid port size

[davegee59]

Evening all,
ive just picked another 2 rapid mk1's  up in 20 and 22 cal, power starts climbing when the bottle pressure gets lower so I checked the usual the ports are too big as the
20 is about 4 mm and the 22 about 3.5,
what should I reduce them to lads as I only want 12ft/lb as ive no slots or any intended, as I shoot rimmies and centre fire so don't want an fac air rifle,
12 ft/lb is all I need,
but I want consistency and not only fill them to 150 bar to get a decent level of power and very low power early shots if I put 180-200 bar in the gun.
regards
Dave

[Kernal]

Sounds about right to me,...If i was you i would put a KevG reg on it to stop that curve,...I remember contacting Theoben many years ago about the power curve on my mrk 1 when the pressure got to around 100 bar the power started to creep up,...and they left the phone on loud speaker by mistake and i listened everything,.....I don`t know who said it but one of them did....he said i`m not suprised,

The best thing i ever did was put a KevG reg on my rapid to sort the whole thing out and if i was honest the reg is on my mrk1 to this date now and its been 15 years ago since KevG fitted it,

On that note it`s going to be great to see him again when i can get around to going to his house,



Take my word on it KevG reg seriously.

[KevG]

you will always get a curve on the mk1.normaly if its in a good state of tune and standard parts fitted filling to around 180 bar you want it doing around 11 ftlb then climbing to around 11.7 ftlbs then back down.larger ports and longer barrels will give larger curves so you have to fill to a lower pressure to keep a decent curve.
KevG

[davegee59]

cheers Kev thanks for that, do you supply regs that I can fit myself and if so how much mate
atb
Dave

[KevG]

yes dave m8.i make them to order and are fully guaranteed for a year(as long as best fitting quick fill parts are not added to them).they are plug and play.may just need to adjust hammer pre load to fine tune gun to power required.
KevG

[Dazgrif36]

Its sounds like the barrel ports are not standard  and been opend up standard ports are usually  2.5 to 2.8 on unregged guns  I would just fit kevgs regs to them and that will flatten the power curve totally kevs regs are best out there for rapids tried tested I've got one on my s type very consistent

[davegee59]

thanks, for all the helping advice ill give Kev a ring
tomorrow
regards
Dave