The most common .38 is the .38 Special, a rimmed revolver cartridge that is actually .357 inches in diameter. The most common .380 is the .380 ACP. That is a rimless automatic pistol cartridge. It is shorter and slightly fatter than the .38 Special. They are intended for two entirely different firearms, and do not interchange.
Bullet diameter on a 38 is .357; on a 380 it is .355 Case is longer on a 38.
the 380 is a 9mm short
The 38 special will be in a revolver and the 380 ACP most probably a semi-auto. However some of the energy of the bullet is used to eject and reload the 380 which dampens the recoil a bit. Also the .38 special is actually 0.357 " diam and the 380 is 0.355". The upshot of it all is that the .38 would have more recoil.
It is: 380 minus 357 = 23
One would think that .380 ACP and .38 Special would be the same size--namely 38-hundredths of an inch. But there can be some flexibility in stated caliber and actual caliber. Long story short, .380 ACP is the same diameter as a 9mm, roughly .355 caliber. .38 Special is basically .357 caliber.
10% of 380 is 38. 380 + 38 = 418 or 380 x 1.1 = 418
thirty-eight 380 / 10 = 38
The 380 ACP, also known as the 9mm Short, 9x17, 9mm Browning, 9mm Kurz and 9mm Corto uses a .355 diameter bullet. The 38 special uses a .357 diameter bullet. Additionally, the 380 ACP is designed for a semi-automatic and the .38 special is designed for a revolver.
.002 inches in bullet diameter. While the bullet is a bit smaller as noted in the answer above the handguns that use these cartridges are very different. A .38 is usually a .38 special, which because of it's rimmed case is predominatley used in revolvers. A .380 is a rimless cartridge used in easily concealed blowback automatic handguns. The .38 special revolver has about 20% more stopping power than the .380 automatic. Both are considered adequate but not powerful personal defense arms.
The least common multiple of 38 and 10 is 190.
38
It's 38!