S410 power going up and up and up

[airarmstommy]

Please help,
My S410 was shooting 8.1 Ft/Lb so I opened the transfer port screw to increase it a bit. Tweaked it and it was shooting 756 ft/sec with 8.44's which was great. then I was plinking at the club and put it over the chrono at the club because the crack from the rowan stripper was a bit much and it was showing 803ft/sec. I tried using thread lock on the transfer port screw incase it was loose but it keeps climbing. every time I tighten the grub screw it doesn't stay..... what can I do to stop it going into FAC territory ?
This is my first PCP so please tell me in basic terms as the last rifle I had was a Webley Vulcan

[ray7]

I had the same problem with my s200 so I bought a grub screw that was long enough to stick out of the hole enough to put a nut on it to lock it in place. No problems since.

Ray

[Mark112]

Hi,

Can't you just screw another grub screw on top to lock the first one in position or replace it with a new one that has the blue Loctite already on it.

Mark

[airarmstommy]

Thanks for the reply guys. I don't know if the grub screw in the transfer port is moving as i put thread lock on it or if there might be another problem?

[Blackbaronfish]

How clean is the hammer rail

BBF

[airarmstommy]

I don't know BBF, I've never opened up a pcp before and probably wouldn't know where to start

[Brooksy]

I don't know BBF, I've never opened up a pcp before and probably wouldn't know where to start

Where do you live? People on here might help of you're close by.

[neil]

when mine was allways having power increase problems it was the firing pot settings causing it, reset that, set the venture ans never had the same problem again, just can`t remember what I set it to but it was wound out too far by previous owner

[Brooksy]

57mm?

[ray7]

Thanks for the reply guys. I don't know if the grub screw in the transfer port is moving as i put thread lock on it or if there might be another problem?

Tried thread lock on mine twice before buying the longer grub screw and nut.

Ray