Your numbers seem odd to me. I've found that as a rule, PCPs are more efficient with a heavier pellet & tend to generate a higher FPE. Could it be because the Jumbo Heavies are 5.52 & the Monsters are 5.5, so the Jumbos are creating a better seal in the Smooth Twist barrel?
Quote from: Habanero69er on February 22, 2018, 06:45:16 PMYour numbers seem odd to me. I've found that as a rule, PCPs are more efficient with a heavier pellet & tend to generate a higher FPE. Could it be because the Jumbo Heavies are 5.52 & the Monsters are 5.5, so the Jumbos are creating a better seal in the Smooth Twist barrel?JSB 18.13 = 940fpsJSB 25.39 = 780fpsDifference = 160fpsJSB .22 Monsters are 7 grains heavier, so they’re slower that’s all there is to it. What’s odd about the #’s? JSB 15.89’s shoot at 990fps out of the Streamline. Which are lighter and faster than both. Roughly 2grains ligher than JSB Heavy’s (50fps faster than the Heavy’s) and 9 grains lighter than the JSB Monster’s ( 210 fps than the Monster’s). It’s the weight. I think thats pretty normal to expect. Am I right? JSB 15.89 chronograph string below: (my Streamline is tuned for more power)
The FPE is close between the two, but it is indeed slightly higher with the lighter pellet.... This is likely due to limited valve dwell, so the 25 gr. pellet is not getting enough push, for a long enough time, to beat out the 18 gr. for overall energy.... The results are within normal parameters for a weight change of 40%....Bob
[qQuote from: Habanero69er on February 22, 2018, 08:04:53 PMBecause the Jumbos generated more energy than the heavier Monsters. Like I said, PCPs tend to generate more horsepower (FPE) with a heavier pellet. I'm not questioning the integrity of your chrony numbers. Just curious about the FPEs. And why I asked about the pellet diameters. If the Monsters aren't sealing in the barrel as well as the Jumbos, that might explain Makes sense. Thanks
Because the Jumbos generated more energy than the heavier Monsters. Like I said, PCPs tend to generate more horsepower (FPE) with a heavier pellet. I'm not questioning the integrity of your chrony numbers. Just curious about the FPEs. And why I asked about the pellet diameters. If the Monsters aren't sealing in the barrel as well as the Jumbos, that might explain
Had a quick chance before work to try for accuracy at 55yds. Mind you it was dark and about 26* with a tiny breeze in the air. I forgot to take pics but accuracy wasn't too bad! Beasts were nothing to write about 3 within an inch and 2 way out. The Monsters however were decently accurate. At 55yds 10 shots were within 1.5" with 8 within an inch. Did another 5 shot group and first 3 were within 1/4" and the other 2 opened to about 3/4"-1". Some definite promise but I have something else up my sleeve to try on it next
Interesting...Did you start out with a clean barrel and FP-10 on the Monsters?