Air Arms Owners Club

I'm probably too anal about this, but the Air Arms Diabolo Field pellets in .22 are identified on the tin and the AA website as being 16 grains. However, Chairgun (latest update with latest pellet database) says they're 15.9 grains. That leads me to also question the balistic coefficient of the pellets, which Chairgun lists as being 0.0310.

Anyone here know what's what?

The quoted BC can be a little misleading. This could vary by 15%. It can vary from barrel to barrel, velocity etc. You can use chairgun and work out your own rifle pellet BC by velocity between two known ranges, requires two chronos, or by poi drop between two known ranges. The weight and BC are a generalisation, weigh your pellets and use chronos to work out the true BC if you want to go to that extent.