Chronographing the Benjamin Trail NP Pistol .177calWell, time has run out for my first chrono prematurely – when the second made it down to Peru, I was finally able to chrono my Benjamin Trail NP Pistol .177cal. ● JSB RS 7.33gr441445410419421413––––––Average 425fpsES 31fps! 2.9 FPE● JSB Express 7.87gr382412381419397392––––––Average 397fpsES 38fps! = 2.8 FPE Your comments, please. The Crosman ad said it would do 525fps with lead pellets. Mmmm, maybe it’s not the pellets that are over 100fps slower than advertised, maybe it’s just my chrono that is slow.... I found five tests online and they seem to point to 4FPE, not less than 3FPE! Next up for chronoing is the H&N Sniper Light, it’s about as precise as the two JSB pellets. By the way, what kind of groups at 10 meters should I be expecting from a 64-dollar pellet pistol?
Lay a tissue over the top of the breech,when you fire. This will tell you if you have a breech seal leak. It shouldn't move.
Can you try putting a shim under the breech seal? I have seen it on here where other have used dental floss under the breech seal as a shim.
Sorry for not reporting back earlier. THANKS, Kurt, and THANKS, GTA community!! I followed your instructions and put a strip of teflon tape under the o-ring of the breech seal. Chronoed, and I got 531fps with the JSB RS 7.33gr, for a muzzle energy of 4.6FPE. NOW we’re talking!!! Matthias