[Junior]

This low profile gun that can propel a 39-caliber round a maximum range of 18.9 miles, ...

Wouldn't the barrel be 39 calibers, and not the round?

[Wisconsin]

nah...they had to do something to get the range, so it is a sharply shouldered cartridge.....

[nightdriver]

"Wouldn't the barrel be 39 calibers, and not the round?"

That's what I thought too. Thirty nine calibers at 155mm should yield a barrel length of about twenty feet, shouldn't it?