Forgive my lack of confidence in shotgun loading data but please take into account that I come from a rifle background. If you buy a round of rifle ammunition with a 168 grain bullet, the bullet will weigh within 1 grain or less that 1% of the advertised weight. It is as likely to go over as under. Variations of more than 1% have a real effect on zero and other factors.

Am I the only person who has noticed that the shot charge in factory shells is about 10% below the advertised weight? I weighed a few shells this afternoon and, just like the charge bars on my MEC loaders, they all weighed light.

Federal 1 1/8 oz 491.1 grains 548 grains correct weight
Winchester 1 oz 432.9 grains 487 grains correct weight
Remington 1 1/8 oz 495.4 grains 548 grains correct weight

All weigh in a little over 10% light, is there a SAMMI standard on this?

I notice that my MEC charge bars all weigh about 12% light with #8 shot. If this is true, how accurate is loading data listed? A 12% reduction in shot charge would result in a huge drop in pressure of published data. Does published data take this into account?

Last edited by Dick Jones otp; 02/28/09 05:45 PM.