Pulled the airgun out recently as had been asked for help with a rat job. Went to put some air in it and heard a slight hiss of escaping air which only went on for a few seconds before stopping, but clearly something was not entirely right. I had also previously noticed that group sizes were opening up from basically pellet on pellet to inch+ groups at 30yds which is something S510 owners are not accustomed to.
This rifle is about 15yrs old and has never missed a beat but has also never been serviced in any way. I don't know how many pellets it has fired but certainly well beyond 10,000. It is a mystery how it has performed for so long but finally it needed attention.
Had a quick look online for costs and that all seemed a bit pricey and also I might be without it a while. And then further costs factored in for postage there and back etc. Bugger it, I will do it myself. How difficult can it be? Hmmm, well it is pretty easy but wow some of the parts were damn near welded together.
Action out of stock is easy and dry fired it a hundred odd times to get pressure well down before slightly cracking off the fill valve seal. That released the remaining air so I could start working on it properly. Most things I suppose came apart fairish easy but there were a handful of parts which were a massive PITA. The air cylinder main fill valve body needed a DIY tool to get purchase on it and then an impact driver to undo. The firing valve assembly was also very very tight which needed some 3 dimensional thinking to remove and the barrel shroud needed a bit of heat to loosen the glue that appeared to have been applied to the threads in the factory. The magazine retaining clip has two small 2mm allen bolts affixing it to the top of the action and these appeared to be made from recycled paperclips. So they were rounded off near instantly. Great! Had to hand file a cross notch in to them to match a flat head screwdriver so I could remove but all was fine in the end. The barrel was also incredibly difficult to remove from the action once the retaining screws had been removed. I think a combination of time and also an escapee O ring galling on the metal basically had it stuck. It was literally 15minutes of very gradual twisting and pulling before it finally gave up the battle.
Everything else was pretty straight forward. The rifle is designed really well in my opinion and is easy to work on. I had bought a full set of O rings (about 18 of them) despite only thinking it was one failure on the filler valve where I heard hissing from. Thought I might as well replace them all seeing as the full set was only about a tenner. I also bought and replaced the firing valve which sits inside the firing valve assembly. Evidently long term usage can extrude material from the face of the valve creating uneven pressure release during the firing cycle and I suspect this was why i was seeing increasingly erratic results on paper when firing it. My old valve showed this clearly with the new item being perfectly flat.
So everything got put back together and once cocked with the firing valve held open so I could fill it with air, it began holding air. I put about 50 bar in it and left it for the night and it showed no leakage so then filled it up, dry fired it a few times which seemed fine and then today went out to zero it and check to see if there was any difference. Immediately it was apparent that the rifle was back to new performance. 5 shots went in to a tiny little hole at 30yds and the S510 is back ready for another 15 years of service. What a brilliant little rifle this has been. Don't be afraid of doing this yourself. You have to drill out some anti tamper pieces of metal which restrict access to 3 main action bolts but apart from that, it is fairly basic and then just a case of cutting off lots of flattened and hardened O rings and replacing them all and then reversing the stripping process. Cost was about £20 in parts and it was incredibly fulfilling for a engineering and mechanical idiot like me. I have no workshop and did this on a piece of mdf board sat on top of the pouffe in the front room ha ha. Where there's a will.......
And this is the result on target. Happy days.
This rifle is about 15yrs old and has never missed a beat but has also never been serviced in any way. I don't know how many pellets it has fired but certainly well beyond 10,000. It is a mystery how it has performed for so long but finally it needed attention.
Had a quick look online for costs and that all seemed a bit pricey and also I might be without it a while. And then further costs factored in for postage there and back etc. Bugger it, I will do it myself. How difficult can it be? Hmmm, well it is pretty easy but wow some of the parts were damn near welded together.
Action out of stock is easy and dry fired it a hundred odd times to get pressure well down before slightly cracking off the fill valve seal. That released the remaining air so I could start working on it properly. Most things I suppose came apart fairish easy but there were a handful of parts which were a massive PITA. The air cylinder main fill valve body needed a DIY tool to get purchase on it and then an impact driver to undo. The firing valve assembly was also very very tight which needed some 3 dimensional thinking to remove and the barrel shroud needed a bit of heat to loosen the glue that appeared to have been applied to the threads in the factory. The magazine retaining clip has two small 2mm allen bolts affixing it to the top of the action and these appeared to be made from recycled paperclips. So they were rounded off near instantly. Great! Had to hand file a cross notch in to them to match a flat head screwdriver so I could remove but all was fine in the end. The barrel was also incredibly difficult to remove from the action once the retaining screws had been removed. I think a combination of time and also an escapee O ring galling on the metal basically had it stuck. It was literally 15minutes of very gradual twisting and pulling before it finally gave up the battle.
Everything else was pretty straight forward. The rifle is designed really well in my opinion and is easy to work on. I had bought a full set of O rings (about 18 of them) despite only thinking it was one failure on the filler valve where I heard hissing from. Thought I might as well replace them all seeing as the full set was only about a tenner. I also bought and replaced the firing valve which sits inside the firing valve assembly. Evidently long term usage can extrude material from the face of the valve creating uneven pressure release during the firing cycle and I suspect this was why i was seeing increasingly erratic results on paper when firing it. My old valve showed this clearly with the new item being perfectly flat.
So everything got put back together and once cocked with the firing valve held open so I could fill it with air, it began holding air. I put about 50 bar in it and left it for the night and it showed no leakage so then filled it up, dry fired it a few times which seemed fine and then today went out to zero it and check to see if there was any difference. Immediately it was apparent that the rifle was back to new performance. 5 shots went in to a tiny little hole at 30yds and the S510 is back ready for another 15 years of service. What a brilliant little rifle this has been. Don't be afraid of doing this yourself. You have to drill out some anti tamper pieces of metal which restrict access to 3 main action bolts but apart from that, it is fairly basic and then just a case of cutting off lots of flattened and hardened O rings and replacing them all and then reversing the stripping process. Cost was about £20 in parts and it was incredibly fulfilling for a engineering and mechanical idiot like me. I have no workshop and did this on a piece of mdf board sat on top of the pouffe in the front room ha ha. Where there's a will.......
And this is the result on target. Happy days.
