" Peace of mind matters" and fingers count. If one of my period guns is safe to shoot, I now load to to basic pressure levels. For 12 bore I set my limit at 5,000 psi and 20 bore I set at under 8,000 based on service pressure levels for proofed guns. Sadly many old guns are marginal or truly not safe to shoot. But of mine which I feel are they get two basic loads at these modest pressures.

For 12 Bore I load 1 ounce shot at 1100 fps and 5,000psi or less. I can go as low as 3,800psi in this load, or push it up to 1250fps at 5,600psi. But nothing above that, as it fills in all my needs, at reasonable pressure levels. And they pattern very well as a bonus. All shells are trimmed down to proper length and marked as low pressure. Loads are tested or straight off Hodgdon and Alliant powder web sites.

16 bore are easy to load safely as the 16Bore.com data generated a lot of decent low pressure loads. I do not shoot many 16 guns any more but still have a good supply of loads on hand. All were very reasonable in pressure and gave about 1100-1150 fps which is fine for my needs.

For 20 bore I load two basic low pressure loads. A 7/8, 1150 fps load at 7,200 psi and a 3/4 ounce load at 1150 fps and 6,400 psi. These are in cut down shells. It is a bit harder to find low pressure load data for the 20 but you only need one or two if you think about it. I have known trap shooter use the same basic load for 30 years as well as others who seem to change their load every week like it is the shell not the shooter who is at fault for their misses.


All low pressure loads are marked with a single black magic marker line across the base and primer so that just at a glance I can confirm all my loads are low pressure.

When you cut down shells consider skiving the mouths to thin out the plastic. It makes crimping them easier as they can be thick when trimmed down. A brass Super crimp starting die makes nice deep crimp lines which seem to crimp well Also I noticed when I do this and have loads tested they always seem to have slightly lower pressures. I figure I can even get by with not trimming to exact length if the plastic mouth is real thin where it meets the forcing cone. So if I am off 1/32 or a 1/16" it is not big deal.