Hi,
I have a problem with an Anschutz Mk2 Rapid which a friend of my Father had dropped off. The rifle had stood unused for a few years and when he came to replace the bottle all the air released (he reckoned from the barrel). I replaced the valve, fitted new O rings (except the regulator) cleaned the hammer section and reassembled. Reattached the bottle (filled to 190 Bar), no leaks but the rifle was massively overpowered.
My suspicions went in the direction of a regulator problem, thinking the reg was passing and the plenum was getting full bottle pressure. Tried to burp the bottle to remove it but the gun was still holding pressure. Had no option other than to totally unscrew the bottle and let the pressure escape past the bottle O ring. Took the reg out and disassembled. The reg O rings seemed fine but the push pin disc O ring was rock hard and shaped like a saucer. Replaced all the O rings, reassembled and set the Reg to just over 80 Bar (it's .22 calibre). Gun was fine, shot a nice few strings at 11.6ftlbs, with a spread of 14 fps. Removed the bottle to refill, this time it burped fine. Refilled bottle to 190 Bar and reattached to the rifle
Left the gun overnight to check for leaks and reg creep. First shot was spot on as was the 40 shots that followed. All sorted I thought, just need to fill the bottle and give it back to the owner. Went to remove the bottle and it was the same as it was prior to the reg rebuild and wouldn't burp. Removed the bottle by letting the air escape past the bottle O ring and removed the push pin disc. The O ring behind the push pin disc was fine but I replaced it anyway
Put the reg on the reg tester and it was sitting at about 130 Bar. Reset to just over 80 Bar, working the reg about 20 times in the tester, and reassembled the rifle. Shot a 10 shot string at a consistent 11.6 ftlbs, removed the bottle, burped fine and replaced. Shot another string at 11.6 ftlbs but it doesn't give me any confidence that it is sorted
Any ideas what is causing the problem please
a) duff bottle valve, perhaps if delrin the pip has distorted or if the o-ring type; it's missing or damaged which would throw out the seating depth.
b) if it shoots good then randomly creeps perhaps the core nose and/or the back of the push pin disc need refacing.
Had that problem myself, lasted 100+ shots then went screwy again.
In the end after half a dozen frustrating rebuilds I replaced the core nose.
80>130bar was a fair bit of creep, have you checked the core travel/end float?
Had checked with 3 different bottles and same burping issue with all. Not exactly sure how to check/adjust the reg end float, it's one of Kevs and has a brass washer on the core. I m guessing that's a spacer for float?
Got a bit more history on the gun. According to the owner Kev fitted one of his regs to it about 5 years ago. He brought it home tried it a few times and it was fine. He put it away and hadn't used it since
hmm.. not much you can do with Kev's regs without the right shims, ideally needs to be sent to him.
Odd that the valves won't burp before blowing the o-rings.
Would indicate that the push pin disc is out too far.
Kev would set that up at the same time.
if its not burping the bottle some times that's a bottle valve fault,leaking into gun not allowing shut of to bleed of pressure.it could be a a damaged core sealing face on the reg core like already said above.i would keep trying it as it may now be sorted.put a picture up of reg out of gun and will tell you if it's one of mine
kevG
also if a sub 12ftlbs gun is over power it will not be reg creep as over pressure will put the power down.
kevG
Thanks all, the gun has gone back to my Dad's friend so I can't put a reg picture up, but I'm fairly sure it will come back to me shortly. Definitely one of your regs Kev, he came down from Newcastle and you made and fitted it while he was in your workshop but as I said it was about 5 years ago, plenty time for the components to shift. The gun is sub 12 and I have tried 3 different bottles and it wouldn't burp any. When it comes back I will give you a shout if that's ok Kev and maybe you could talk me through it over the phone if you would be so kind
out of interest are the bottles best fittings valves.
kevG
Quote from: kena on July 14, 2023, 06:06:35 PMThanks all, the gun has gone back to my Dad's friend so I can't put a reg picture up, but I'm fairly sure it will come back to me shortly. Definitely one of your regs Kev, he came down from Newcastle and you made and fitted it while he was in your workshop but as I said it was about 5 years ago, plenty time for the components to shift. The gun is sub 12 and I have tried 3 different bottles and it wouldn't burp any. When it comes back I will give you a shout if that's ok Kev and maybe you could talk me through it over the phone if you would be so kind
I wouldn't have made it while he was there.its a long job making a reg m8
kevG
if it still as problems just send it me m8.with luck it maybe ok now.
you can phone me anytime
kevG
Thanks Kev, absolutely spot on 👍
Update: Spoke to Kev this morning, loads of brilliant advice and a really nice bloke. Thanks Kev, it was a pleasure to talk to you