HectorThanks for the numbers-so it appears my 3 under levers fit those numbersThe Break barrel NP Phantom with it long barrel is prehaps a bit over barreled- but as you and North Country say-more than just velocity involvedThat .22 Crosman NP requires LOTS of cocking effort-not sure whyIt is powerful-BUT CERTAINLY NOT 460 POWERFUL-but the cocking effort is MUCH MUCH MORE??!!And the cocking effort is heavy IMMEDIATELY-not initially soft then increasing like the 460- Are all break barrels that way??Now it has PLENTY of stiction/friction-not sure if that is strictly a function of the pneumatic spring and seal-or something to do with the cocking levers(prehaps they are cockeyed)Anyway I have gotten to like it-DESPITE the cocking effort-but more-LOTS more than the 460 seems odd?And immediate heavy effort is strange too-springs -gas or steel-don't act like thatas was pointed out earlier-gas springs has more "starting friction" but this is too muchThanksCharlieI will pull it out of the stock and eyeball the cocking lever arrangement-
One funny fact is that when I discussed Crosman's NP guns with the then head of engineering (almost 11 years ago), he answered that they WANTED an inefficient gun because few users had or actually used Chronos and even fewer knew the formula for kinetic energy and, so, a harder to cock airgun HAD to be more powerful, ¿Right?.
HectorThanks for the info.Duke-I bought the NP because I am a sucker for a DEAL-and the Phantom(great name) showed up in Bargain gate-about 4 years ago when I was just getting into air gunsIt was $90 or so-Walmart-made great power-velocity- 950 fps .22-CLAIMS-and came with a decent enough scope-I am a sucker for a deal!If I had actually cocked that sucker-NO WAY would I have bought it (It does shoot just fine-but it is soooo awkward to cock-)MUCH MUCH MUCH more difficult to cock than the 460-not just high effort but AWKWARD TOOOh I made some crude measurementsOn ebay a seller sells replacement gas rams for NPs- claims 140 ATM- 2000 PSI!!- Assuming the stock one is similar-140 ATM= 2000 PSI8mm rod-if that is also piston diameter it would have an area of 3.14 x 4/25.4 x25.4=.0778 sq inches or a force of 2000 x .0778= 156lbs to move it-ignoring stictionThe barrel mechanical advantage-where I grab it 14"/2" 7Maching mechanical advantage-total hand movement-about 28" Ram moves 4" so 28/4= 7/1 againBut a 25lb weight plate-at 14"- so 175 lbs(torque and force) will not break it loose- but once broken loose it will cock it about 1/3 of the way-9 inches of the 28 inchesCrude guess is once it is moving it would take 40 lb plate to fully cock it- 7x40= 280 lbs of forcenow the picture of the ebay ram-the cylinder looked maybe 8-10" long-So the pressure force would almost double in the 4" of travel 2000 psi would be 4000 psi fully compressed-and peak end force would be double 156 lbs-so 300 lbs-Now it sure feels like I am pulling 40 lbs worth-crude efficiency 2.5 feet maybe averaging 30 lbs over the 28" travel 75-80 ft lbsSo if I put in about 80 ft lbs-Claim on velocity 950 fps-9 grain 9/7000 X 1/32 x1/2 x 950 x 950 =18 ft lbs out 18/80= 22% figure the 950 fps is a lie 900 fps 9/7000 x 1/32 x 1/2 x 900 x 900= 16.2 /80 20%so maybe 20% efficient-but who caresThe real problem is the initial friction and high starting force makes it EXTREMELY AWKWARD to cock-and if you pause -it immediately "freezes" My 460 is MUCH MUCH easier to cock-the steel springers have some preload-but they certainly do not require 40 lbs to get moving- 25 lbs WILL NOT GET THE PHANTOM MOVING-NOT A BIT-and the 25 lbsis AWKWARDLY applied-away from you-using triceps-while having to hold it pretty firmlyThe 460 I more or less pull DOWN-using big muscles-lats= AND my body weightYeah not a bad shooter-but a horrible cocker-never would have bought it IF I had cocked itThanksCharliePS good to know it is a gas ram problem-not a break barrel problem-I don't see any advantage-not with all that stiction