Here are the testing data sheets on the 20 gauge loads in question that had pressures roughly 3500 psi higher with Cheddite primers than the same loading using Win 209 primers. They also increased velocity by about 100 fps.
For reference Alliant data for Win209 primer is:
The first load with a Win 209 and 15.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1200 fps and 9370 psi.
The second load with a Win 209 and 16.7 gr of 20/28 is listed on the Alliant Reloading Guide as being 1250 fps and 10,490 psi.
__________________
Progress is the mortal enemy of the Outdoorsman.
|