"SMH77"Hey guys,
I just posted a PSA regarding what I just measured through my .30 cal RAW for a BC with the JSB light pellets. I posted it in the appropriate place, but I wanted to have some follow up discussion here. Here's the post (the bottom line is I measured the BC to be 0.0427 through my gun, in the cold (21 F) temps. I'm still thawing out, LOL:
http://www.airgunnation.com/topic/raw-30-cal-jsb-light-44-75-grain-ballistic-coefficient-measured/ My question for you guys here is this: I had my gun all setup to shoot the same pellet at 896 fps yesterday (about 36 F outside), and left it that way. I brought it in and left it inside in its case overnight (of course!), then took the gun outside today (21 F). I tried to let the gun sit outside for 15 minutes or so, along with the pellets, prior to starting the testing. When I shot my first string over the chrony at the muzzle, the velocities were averaging 861 fps. I'm not sure what to make of that, except, perhaps, that the cold tightened things up a bit (or perhaps gelled the internal grease a bit?) causing a slight loss of velocity. I plan to leave the setting alone, and see where it shoots when the temp comes back up.
I thought Martin set the guns up to be shooting the 44.75 grain pellets to about 880 fps, yet mine arrived at like 857 so I gave the hammer spring a half turn. I saw the temps near Minor Hill, TN were in the low 50's last week when he was working on my gun, and it was about in the low 30's when I got it (reading 857 fps).
I plan to do the same measurement on the JSB Heavies soon (when it's a bit warmer outside!), so I'll post those results as well.
Any thoughts?
Sean