Thank you guys al so much. I really appreciate any answers at all . Rick Wellknicker is who got me addicted to PCP's about 10 years or more ago as this .177 Discovery is made in 08. Now, I see one of you gave me the advice I found to be what I now think is the problem. Think. I took her apart this morning. Didn't have to Degas as it was empty. I noticed 3 things, and keep this in mind. A perfectly sealed PCP will hold air for years, not just weeks or months. Yes, dry rot, lack of use, misuse, temperature changes could cause slow leakage but in 8 years my Discovery held air indefinitely. I only resealed it 2 years ago to learn about it and check internals. I was surprised as there was little to no rust and I'd hand pumped quite a bit. I chamfered edges as I learned upon reassembly that sliding new rings over sharp edges ruins them. I had NO problems. At that same time, I upgraded to Magnum Airpowers Grade8+ screws, a brass power adjuster to match trigger blade. Now, to the obserVATIONS.
The 3 valve retention screws seemed loose. This wouldn't cause a leak, and I know I tightened them under no pressure, then filled, now unscrewed them with no pressure; but I thought they'd have some tightness. Just flush like a click stop on micrometers. O-rings were all perfect and even the first was not flattened out like my 8 year old one was. I still have that and may post a picture. It never leaked but boy did it take a set. It was round on face and flat against valve like a plumbers washer. The next two things I noticed. Valve body was not screwed tight flush. Almost, but it was gapped. The last & what I expect to be the culprit was the poppet head seems to be deteriorating. I was unhappy to find in my last kit that there is indeed an internal o-ring that hugs that valve stem, and it is not mentioned on any manual I've seen (as schematics have shown where but not listed sizes either. Maybe the actual manual one of you mentioned would have this. If not defaced, I have depth gauge, micrometers, calipers) I took it out and found a match for it myself. I was told it's not a part they expect to wear out. I'll say this. It has very little movement against it of valve stem opening & closing but to me, all should be replaced. So, with a ten year old rifle that I'd wanted to buy a heavier hammer, magnum valve, heavier spring, lighter poppet return spring, longer Maximus barrel or better yet, a 28-30" TJ choked liner or unchecked tight bore .177 to spit 16.1Eun Jin's near the barrier. Ido NOT think it's worth putting this all on a ten year old tube and I prefer at least 8/32" grub screws or big ugly Allen head 10/32" screws. I'm sick of little guys stripping out.
Look at The Destroyer. That gun, if it had a 500cc Carbon fiber 4500psi tank, I might like it. I don't want a fancy stock and I definitely don't want a fat tank like that on any rifle. I'm thinking of buying his drop down adapter, a 500cc CF tank, a 28-32" TJ liner & build my own platform off a new Discovery. I may just buy a Rainstorm & have a reg put in. Hatsan has some darn good guns cheap. Brococks new guns aren't anemic like their first few were. I thought about tightening everything up, reassembling the Discovery and see if it is indeed the poppet or some gunk that was on it and loose valve body. If grubs strip, so be it, it's ten years old at least. I can strip the bling and buy a new one as I do like a single shot discovery lightweight. I've held on so long because that barrel was lathe crowned, six set screw band, great trigger mod, extended bolt probe. After adding Bill Baldyga's screws I was filling to 2700psi as that worked best with factory hammer , spring, all OEM parts other than a higher fill. I knew I was wasting air with a shorter barrel & wanted a longer, more consistent one. Either choked or fully tight. This particular rifle could put Crosman 7.9's, 10.5s, any JSB's (especially 13.43 Monsters) into very tight groups. Birds have been taken out to 110 yards with Monsters out of that rifle. I just didn't want to giver her up but for safety & the fact that I'm now in love with regulators, I'm thinking save, get another Rainstorm in .177 & regulate it. That only has a 17" barrel but with a good reg I'd expect at least 30-40 good shots as my Altaros regulated RSI spits JSB 18.1's at 861fps for 5 full mags 50 shots.
AZ had told me of a Daystate he worked on to spit Eun Jin's at 945 for 32ftlbs & the guy loved it as a laser. I'm against any electronics on a rifle (unless Santa bought me a .408 Cheytec system) so I'm thinking either get a full sized Cricket, Taipan, Mutant, Huben K1? Ha, not in .177 on a Huben. I do NOT want a bull pup. I do NOTcare about short or balanced as all my shooting is off a bench or bipod and long range groups with PCPs. My spring guns are regular shot at 32 yards, the R1 sadly slugged does best with FTT 5.54's. OH, it will do great scoped with many others but absolute best is FTT 5.54 & I HIGHLY doubt those are consistently sized. I shoot that rifle now with open sights. A inverted V filed to a fine point & a 4ft length of mylar tape from "Bat out of hell" by Meatloaf hangs off the end. At 32 yards, with FTT 5.54 & that tape, I did the 10 dimes challenge & FINALLY can say I got all ten within the circles. FAR from center shots on them. Believe me, it's a very fine point and those targets are HARD to see with open eyes. My scoped RWS 48 .177 tuned by John or any of the 3 PCP's was easy, even my 7ftlb El Game 300 .177 tuned by JIPA could do it with a 1.5x4x20mm as I like to just be able to see the target. I find the higher the magnification, the more I jump around & over compensate.
Well, back to the Discovery. Yes, I have aspirations for some more powerful PCPs in .177, .22, & jump right to .30 or a RAW .357 if I move to a place with 200 yard open fields for clipping clumps of dirt for fun. I'll rebuild this Discovery; but I'm not going to power mod this particular +10 year old model with this short barrel. Thank you so much guys. By the way, anyone whose a lefty archer and has dreamed of owning a Tomahawk Diamond SS, let me know about possible trades in air guns. I really like it & have become good out to 25 yards; but I'll stick with my compound. With that I can do good at 60 yards. I can't even hit a 3'x3' target with my 55lb R/D longbow at 60 yards. I end up looking for arrows. Ferguson was amazing.
