Boat-tail 5.56???

[CapGun]

Is the main difference betwen regular 5.56 and boat-tail5.56 the pressure produced? I know and understand the diference between 5.56 and .223 just want to be sure about boat-tail.
Thanks all.

 

[Red Hat]

There's a slight difference in pressures between the two. Flat based bullets seal the bullet to the rifling and contains the gas. Boat tail bullets have a tendency to allow hyper-velocity gas to escape around the bullet. So there is some pressure loss with boat tail bullets. The difference between the two is the design of a boat tail bullet is it has less resistance while in flight because the taper cuts down the turbulence and travels in cleaner air. This is all mute though because when a bullet goes faster than Mach I a vacuum is created behind the bullet which cuts down on the drag. The nose of the bullet like the wing of an airplane is more critical when traveling supersonic.

Here is a good article to read. http://www.swage.com/ftp/rbt.pdf

 

[festus]

Red hat is mostly correct!

The boat tail only helps the bullet maintain velocity at extremely long ranges when the bullet is slowing down but still going supersonic. It is more critical in larger rounds...IE .308 Winchester or 30-06.

5.56 does not do well over 600 -800 yds. It does not have the weight to carry it and is really moved by slight winds.

 

[CapGun]

festus, Red Hat, Thanks for the info!