Thread: Another Trip to the Range

Greetings,
Due to being programmed to pick up any shiny case I spot the shelves contain a decent collection of once fired brass. A certain level of sloth prevents me from bothering to check water capacity of cases preferring to use case weight. Most of the US cases I have weighed fall into two groups of 94 grains and 97 grains average with primer. The small lots of ADI and PMC I have average 97 grains with primer. Continental cases, Lapua, Sako and S&B average around 105 grains. Brass has a relative density of around 8.8 so the continental cases will push up both velocity and pressure a little. I have always meant to run a chronograph test to see how much velocity changes but have not got round to it yet.
As far as velocity changes with old powder it is likely that the older powder will have dried out a little so the same weight of old powder will often produce a little more velocity. I test each batch of powder for velocity and have often noted a slight drop in velocity with the new batch. I started chronographing new batches after I was almost caught out by a significant change in speed of one powder and another is on the watch list at the moment.
Handloading is a pastime that just keeps giving.
Finally I calculated the difference in projectile impact for the 55 grain mentioned in the OP. The point of impact at 275 metres (300 yards) should be about 50mm above point of aim. QED.
Regards Grandpamac.