The question can't be answered since you didn't supply a caliber or mm measurement.
.30 vs .355
.30 vs. .355
No. This is a .22 caliber vs .243 caliber (.243 being a 6mm).
5.56 hands down.
The .40 is a larger diameter round. The projectile has a dimension of .4005, versus the 9mm Parabellum, which has a dimension of .356. Of the two, the .40 is the more powerful cartridge.
The longer case of the .44 Magnum holds more powder, and, even though the .44 is smaller in diameter, it tends to pack a heavier projectile, ranging from 240 to 350 grains, vs. the typical 165 to 235 grain projectiles used by the .45 ACP.
Oddly enough, both are about .35 Caliber, which is why one can fire a .38 Special round out of a .357 Magnum.the .38 Special has an actual diameter of .357 and the .380 has a diameter of .355. So the .38 special is larger and they are typically heavier than the .380 (110gr vs 90gr).
metric vs inch measurement
Head is the Circumference which is Pi*Diameter where pi=22/7
The cartridges are similar, but not identical. Differences include:Slight variations in neck diameterSlight variations in base diameter (.378 inches for the 5.56 vs. .376 inches for the .223)Variations in the neck anglePressure rating (380 MPa for the .223 vs. 430 MPa for the 5.56)Case thicknessYou can safely fire .223 rounds in a 5.56 rifle, but it is not advisable to fire 5.56 rounds in a dedicated .223 rifle.
I'm not 100% sure but I think it is 2.25 inch diameter. I'm not 100% sure but I think it is 2.25 inch diameter.