I LIKE the FirePiston avatar! Probably very similar to what happens inside a springer if there is any trace lube present :-)Quote from: Atom on October 12, 2023, 03:36:01 PMI believe that this topic belongs in this part of the forum and if it is proven that they made a big mistake, it should be posted on the bulletin board!I recently got a nearly new Hatsan 125 5.5mm to install an optic on, of course I did a velocity measurement first and found it to be around 22J. I also noticed that unusual transfer port that I hadn't seen before, but at first I thought it was a piston seal problem because the rifle was all full of factory grease and oil.When I disassembled the rifle, I first noticed that the shorter spring 43 coil 41 was active and removed the piston, but the seal was not damaged from dieseling, but had minor damage during factory assembly. I was interested in that insert in the TP and I twisted it and it was stuck with something. The threads on it correspond to a standard M7 screw, and it is drilled with a 4mm drill bit, about 7 mm long, the transfer port on the cylinder is 3.9 mm and about 5 mm long, so the total length of the TP is 12-13 mm, that insert, when twisted, passes into the cylinder about 0.7 mm, the four slots are about 2x2 mm for the screw driver.I put that insert back again and put Loctite 241 got a bigger original spring 48 coils carefully installed a new piston seal properly applied Feinwerkbau special grease and tried the speed and then I found that I didn't get any power, the speeds even fluctuated a lot for a spring gun. I contacted the Hatsan factory and got no answer, the supplier is totally ignorant and justifies that the warranty is lost because he did not service that classic rifle. My only fault is that when they made that insert, they didn't make it from M8 or M10 (M7 is hard to find) with an O-ring holder, then people would have made it easier with stainless steel screws and two holes so that it can be unscrewed and screwed in.What do you think about this because I was thinking of making a 3.5 mm wide insert. Please join this discussion as all new Hatsans come with this insert*. here are the pictureshttps://www.gatewaytoairguns.org/GTA/index.php?topic=210458.0* Possible but I'd expect this modification to the transfer port to be rare on rifles made for the unrestricted muzzle energy US market.My Mod125 25cal (6.35mm) has a straight drilled (no insert) 4mm diameter transfer port. Not too different from your rifle if I read your description correctly. I doubt very much your low muzzle energy readings are caused by the transfer port design change you have shown. Your rifle (22 J ~ 16.2 FPE)My rifle (39.3 J ~ 29 FPE --> at 30' , higher FPE at muzzle)Yes 7mm or M7 thread nuts/bolts/taps/dies are not that common over here either. However I found several M7 parts when I was looking for a cheap alternative to the Hatsan SAS bolt (M7).My rifle has the factory supplied spring which is 44 coils (42 active) 0.142" diameter wire with an OD of ~0.840". I don't know where you are getting your springs from but MORE COILS alone does NOT PROVIDE MORE POWER. The 2 springs in this photo are a good example.The one with fewer coils is the factory spring for a US(China) air rifle that shoots around 16 FPE. I tried using the "more coils" spring in the same rifle and it just barely had enough energy to make the pellet leave the barrel (~4 FPE?).My Mod125 here was sold as factory refurbished at a steep discount. I purchased it in ~2020. It has a 0315 manufacturing date code.The rifle had terrible performance (large velocity variations) with a VERY HARSH shot cycle when I received it. Others would have returned it for refund but it was more than 50% discounted from $new$ and I KNEW how to repair these rifles. I performed a thorough cleaning, deburring, and re-lube with high quality lubricants. Replaced damaged piston seal with new OEM seal ($5) and same with breech seal($2). Made a custom steel snug-fit spring guide ($2 +labor) to replace the very loose (and way too short) plastic factory guide. Cleaned, lubricated, and adjusted the nice Quattro trigger group to where I LIKE my springers triggers set.This rifle is still a MONSTER SPRINGER but it is now a JOY to shoot. It has a crisp trigger release around 2 lbs (right where I like it) and a FIRM THUMP shot cycle with "0" spring vibrations. Attached below is the chronograph data I just shot tonight along with the 30' group of 10 shots using the factory open sights.Hatsan Vortex Strike pellets 24.7 grain
I believe that this topic belongs in this part of the forum and if it is proven that they made a big mistake, it should be posted on the bulletin board!I recently got a nearly new Hatsan 125 5.5mm to install an optic on, of course I did a velocity measurement first and found it to be around 22J. I also noticed that unusual transfer port that I hadn't seen before, but at first I thought it was a piston seal problem because the rifle was all full of factory grease and oil.When I disassembled the rifle, I first noticed that the shorter spring 43 coil 41 was active and removed the piston, but the seal was not damaged from dieseling, but had minor damage during factory assembly. I was interested in that insert in the TP and I twisted it and it was stuck with something. The threads on it correspond to a standard M7 screw, and it is drilled with a 4mm drill bit, about 7 mm long, the transfer port on the cylinder is 3.9 mm and about 5 mm long, so the total length of the TP is 12-13 mm, that insert, when twisted, passes into the cylinder about 0.7 mm, the four slots are about 2x2 mm for the screw driver.I put that insert back again and put Loctite 241 got a bigger original spring 48 coils carefully installed a new piston seal properly applied Feinwerkbau special grease and tried the speed and then I found that I didn't get any power, the speeds even fluctuated a lot for a spring gun. I contacted the Hatsan factory and got no answer, the supplier is totally ignorant and justifies that the warranty is lost because he did not service that classic rifle. My only fault is that when they made that insert, they didn't make it from M8 or M10 (M7 is hard to find) with an O-ring holder, then people would have made it easier with stainless steel screws and two holes so that it can be unscrewed and screwed in.What do you think about this because I was thinking of making a 3.5 mm wide insert. Please join this discussion as all new Hatsans come with this insert*. here are the pictureshttps://www.gatewaytoairguns.org/GTA/index.php?topic=210458.0
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