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Air Arms S400 Anti Tamper

Cavatina

Cavatina

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Can anybody tell me why Air Arms decided to fit anti-tamper mechanism to their AA S400's. What a flaming nuisance. I find the Ft/lbs varies quite a bit with temperature changes. i.e At ambient temperature in the 20's I'm getting 11.4 ft/lbs using Bisley magnums .177. But last night with the temperature down to 7 deg C, I was only achieving 9.64 ft/lbs. Back in the house this morning with temperature back in the 20's I'm again achieving, 11.4 ft/lbs. So, to 'ell with the warranty, into the workshop, removed the anti-tamper sheer off bolt, adjusted the allen bolt and re-fitted an allen grub screw. I've now got a proper gun which I can adjust to suit the climate, the pellets, and the gun's sweet spot. Why oh why can't manufacturers leave things alone???. The older S400's were great guns, not broken, and didn't need fixing. Don't tell me they did it to stop a few idiots winding the foot poundage up!!!.
 
That seems a bit of a steep drop in power for a PCP, especially considering 7deg isn't actually that cold:eek:

Are you sure you were testing it right? With the same fill pressure etc?

I agree with you on the anti-tamper measures. They were only really introduced to earn the AMTA companies more money through warranty work from what I've heard. Some people have been looking into it quite deeply and made some fairly startling discoveries, mind you their opinions and findings can sometimes be a bit biased I reckon. I was hoping to do some digging myself at one point, but I just don't have the time.
 
I was concerned about the pressure drop, but other than temperature difference, everything else was like for like. I also noticed how cold my divers cylinder was. (I keep it in my workshop which is metal construction). I've now moved the bottle back into the house just to increase the ambient temperature. It's years since I studied Boyle's law, but am aware that temperature does have a bearing on pressure. Anti-tamper grub screw now removed and fitted with proper allen bolt.
 
I always find that generally, if you want to get a decent fill from your bottle it is best to keep both divers bottle and gun as close to the same temperature as possible. I'm sure I studied a bit of Boyles law in college when I did my engineering course, mind you I also studied complex equations but I never did figure out WTF all that was about:eek:

I wonder if the temperature would make more difference in .177 than it would in .22? Seeing as more air is needed for .177 it may be something worth looking into.
 
7oc is like the summer down er on the isle of wight.
ive never checked powers in the different temperatures.
not sure if its going to help but my rifle is wrapped up in camo tape so this may help keep the cold off????
 
I'm beginning to think it's not the gun, but the temperature of my dive bottle, or both. Gonna do some more practical tests this evening. Geoff;);)
 
Cavatina is no longer an active member on here I'm afraid, he had to give up shooting due to medical problems.
We can't really discuss anti tamper on open forum due to it being a bit of a legal grey area but if anybody does know how to remove it, I can't stop them from sending you a private message;)
 
kentairgunner said:
Would you mind dealing me in?
Click to expand...

Watch out, GDFB's the one I warned you about, he'll be begging to be let on to your permissions! :D

You could do worse though, he's a top bloke, and he knows his S510 inside and out. Can't shoot a springer for love nor money, but he's known as Dead-eye Dick when he's got his PCP in his hands. :)

Or should that be Dead-eye PCP when he's got his... never mind. :rolleyes:
 
Sorry to start this up again, I wondered if you could tell me how to remove the anti tamper? My s400 is leaking from the gauge so need to remove it in order to replace the o ring but it's got an anti tamper screw - the flat type
 
Shroppy, if you give me a day or two I'll sort the links you needs from my other pc and post them to you by means of a pm. In the meantime I suggest you join the Air Arms Owners Club (AAOC). You will have access, as a member, to the technical section which has all the information you are after, along with tips from guys that have performed the procedure you are after.

I have removed the anti-tamper from my rifle, but I can't remember what size drill one needs to remove AT. It matters, because if it's too small you drill a little too deep and it buggers the Allen bolt head directly underneath.:eek: I know I buggered mine. All the seals, spare parts etc are all available, at a 10% discount, to all AAOC members from Julian (also a member). Check out his site here. If you are ever looking for a new Air Arms rifle and you happen to be visiting the Bridgewater area, give Julian a call, coz from my research he has the cheapest prices for most, if not all AA rifles.

http://www.airarmsspares.com/
 
I'm sorry to say that the AAOC website "crashed" recently. There were issues with the location of the building that housed the servers and they were forced to relocate. There is a temporary site set up, but sadly there is no technical section at the present moment. The tech guys are working o/t trying to restore everything, but the members have been warned the files may be irretrievable.:(:( However, if they can't be restored then the technical section will be revived from scratch by posts from the members, which will take some considerable time. It is a great forum, not as great as this one, but good none the less and worthy of your time.

I bookmarked all the pages you will need to service your rifle, including trigger tuning, although sadly the bookmark links are now dead, so I am unable to post the links you need Shroppy.
 
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Hi , I hunt almost every day and also do some night work with my S410 . I have decoyed pigeon in the height of summer over stubble and laid crop and at the other end of the scale I've decoyed them over winter rape with the snow rolling across the field like a scene from the arctic . my point is that I have never known any noticeable drop in performance and certainly not the margins you experienced . I check the muzzle velocity quite regularly and on average shoot 500- 1000 pellets per week . My rifle gives me a steady 11.4 ft/lbs using JSB Exact Diabolo @ 8.44gr . Obviously this problem will have been dealt with long ago but I would be interested to know if you had a faulty pressure dial . On the subject of bypassing anti tamper screws a guy I know well asked in passing how to do this online and suddenly found he and his rifles were getting a lot of attention from the local farm watch police . It was too much sudden scrutiny to be a coincidence so open discussion about the subject for those of us without a FAC ticket should be approached cautiously . I stand to be corrected but I would think that no offence is commited by the modification but questions might be asked as to why you needed to do it in the first place . interesting thread to read though atb Ricky
 
Hi Ricky,,

I think key words or similar to Bum, and mine has doubled it's pulling power since I removed Aunties Bad Temper, flash up on big brothers computer screen so any unnecessary use on line of these phrases should be avoided.
In fact I wouldn't be at all surprised if we didn't have a secret Mole.

I too tend to remind folk don't tinker and TELL.

I had a Theoben mk1 that had a brilliant Flower adjuster screw that with an allen key could be used to dial up or down pawn.
I've sold it now LOL. When I asked about the legality of it I was told,
That's a tricky one, no one has actually has been prosecuted for that yet as far as I know, but I guess if you are caught in possession with the Allen Key when plinking and even if your Bum is under 12 feet at that time, it could be construed as an Off Licence being ready and able, so don't have your Allen Keys with you. The same as walking in the street to a Bum shop in Wisbech, carrying my Bum in a slip with Chicken pellets in my pocket. The Bum shop bloke said that's Five years, leave your Chicken pellets behind.
A bloke I know bought an air Bum got home, parked his car in the street got his Bum out and walked over the pavement to his house without it in a Bum bag, was spotted by plod and had his Bum taken away on the spot.
So find a Bum shop with a private car park or do two trips. I've bought shot Bums and Ink cartridges at the same time and carried them home on the train from London before now. Leg of Mutton jobbies too.
 
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