British Ordnance Collectors Network
This is a sample guest message. Register a free account today to become a member! Once signed in, you'll be able to participate on this site by adding your own topics and posts, as well as connect with other members through your own private inbox!
USN 20x197 test round
- Thread starter SG500
- Start date
Another of those unusual rounds made from a 1.1 inch USN case.
First photo shows a regular 28x199SR case to the left with the 23 x 146SR round to the right.
Second photo shows the 28 x 199SR head stamp to the left and the 23x146SR headstamp to the right clearly showing ".90cal T1"
Ref Tony Williams excellent book "Autocannon: A History Of Automatic Cannon And Their Ammunition" page 128......."For the US .90 cal aircraft gun projects in the late 1930's. Unlike the latter T2-T4 series, the T1 was designed to achieve a higher muzzle velocity so the brass, semi rimmed case is bigger. It was based on the USN's 1.1 in ch case, shortened and necked down with a particularly long and tapered shoulder. Overall round length is 222mm and weight c.530g. Projectile weight is 204g and MV was 869 m/s."
First photo shows a regular 28x199SR case to the left with the 23 x 146SR round to the right.
Second photo shows the 28 x 199SR head stamp to the left and the 23x146SR headstamp to the right clearly showing ".90cal T1"
Ref Tony Williams excellent book "Autocannon: A History Of Automatic Cannon And Their Ammunition" page 128......."For the US .90 cal aircraft gun projects in the late 1930's. Unlike the latter T2-T4 series, the T1 was designed to achieve a higher muzzle velocity so the brass, semi rimmed case is bigger. It was based on the USN's 1.1 in ch case, shortened and necked down with a particularly long and tapered shoulder. Overall round length is 222mm and weight c.530g. Projectile weight is 204g and MV was 869 m/s."
Attachments
You do like to tease!