Cold bore shot 100 fps faster?

[jarhead1086]

My 16" likes the 2400 better than my 12" which seems to like LilGun better. The 2400 is bulkier, but the LilGun meters better. I just worked a load in the 16" with 8.5 grains of 2400 with the 220MK @1050-1060fps. I have 1:8 in both my current barrels and didn't even try 240MK's because of stability issues I had with a 1:8 I had years ago. I have also had some funky readings off my chrono from operator error from being too close or having the wrong lighting or light angle. The photo meter will pick up smoke and the sun glinting off that long skinny bullet and cause some tweaked readings. Another piece of equipment that can screw you up is your powder scale. I turn mine on for a while, calibrate it, and then use it only when my AC isn't running and blowing air around the room. I have small check weights I use too since 50 g is too much. The portable battery operated scale is never used for Whisper because the readings change as the battery drains. For now on I'm chrono'ing in my friends covered wood shed and making sure all my loaded test rounds have the same neck size to the .001". I want all my necks to have the same amount of soot after firing so I know I'm getting consistent sealing.