Theoben Rapid Forum

Hey up Everyone,
I have a figure of 1350 psi in my head for .177 cal sub 12.
Is this right ?
Would this be for a 16 inch barrel ?
And do I need to increase reg pressure incrementally for shorter barrels ?
Eg. 14 inch barrel =1400 set point ?
Or does a lot depend on the barrel as well.
I've got three .177 barrels now .
The cz one is sweet with reg set to 1350.
Gives 11.7 with JSB heavys . This is on a Gsx action .
The 2 shorter ones (1hw ,1lw )using on a different rapid action (reg 1350)whilst near identical lengths (14 inch)give slightly different power which  i can understand but would the rifle be better off with more reg pressure to start with given the barrel is shorter ?

Or is this all part of the fun finding the sweet spot for each different combo?
Maybe I should buy a house near Kev😀.
Any advice gratefully received .
Thanks,
Ed.

Mine is set at 1350psi / 93bar with a 19" barrel and  fairly short hammer spring.

Main thing is to make sure that the power doesn't go over when it goes off reg or to thrash it by going too low.
I'd try slightly higher to keep the valve cycle snappy and avoid thrashing the reg.
You'll know when you're there by the noise, may sound a little breathless if its too low.

I believe Theoben gave;
.177 - 1700psi, .20 - 1450psi, .22 - 1200psi.

But I have a reg service guide by "Dazy" which gives;
.177 - 1350psi, .20 - 1250psi, .22 - 1100-1200psi

I would guess that the hammer pip & spring strength are going to make a fair difference,
so, I'd set it in the ballpark & fine tune to your specific set up.

Best setting for 16 inch barrel is 1500 psi.but 1450 should be ok.you can actually go as low as 1100 psi but shot count drops and consistency is not as good
KevG

Thanks for all the replies.
Will try higher reg pressure . That's my afternoon sorted  :)