Questions on reloading 2.5" low pressure shells

[Bruce Day]

Responding specifically to the 16ga Parker issue, following is what is left of a Parker patterning tag for a 1921 16ga showing recommended pattern load at 1oz and 2 1/2 dre. Prior to about 1915, the recommended 16ga load was 7/8oz, 2 1/2 dre, however, the barrel and chamber dimensions did not change when Parker increased the shot load recommendation.

Numerous Parker pattern tags for 12ga state that the chamber length is 2 5/8. Later tags state "Use 2 3/4" shells". The standard 12ga pattern load was 1 1/8oz at 3 dre, multiple tags available for posting upon request. The load gave an approximate muzzle velocity of 1200fps, which readers will recognize as the standard trap load for the last 100 years.

The patterning tags do not differ between fluid steel and Damascus barrels.

I have several Parker 16's, including one Damascus and two fluid steel. All three have chamber lengths of 2 9/16, the latest one being marked "USE 2 3/4" shells".

Parker transitioned from black powder to smokeless powder in 1891-2. Most post 1895 Parker had patterning tags which provide in diagonal red statement, as does this one: " This gun was Targeted with Smokeless Powder".