BARREL LENGTH STUDIES IN 5.56MM NATO WEAPONS

[AlanM]

Looking to build a 5.56 SBR? You might want to rethink that.

This article is two years old but the science and resulting data is quite interesting.

BARREL LENGTH STUDIES IN 5.56MM NATO WEAPONS

Equally illuminating in this study was the correlation between velocity and barrel length (see Graph 2). To generate a lethal wound channel, the M855 projectile must have a velocity of at least 2,500 ft/sec on impact with the target. Below that critical velocity, the M855 bullet simply drills a 1/4 inch hole in the target, which too frequently is not lethal unless it passes through a vital structure.

[Reverenddel]

That was an INFORMATIVE article! I appreciate it greatly!

[WileyC]

Great article. I am working on a new build and decided against going the SBR route. Going with 14.5 inch with middy gas system.

[0ne5hot]

...But if you drill thirty 1/4 inch holes you will have removed the same area as one 7.5 inch hole

I'm still picking up my 20" A2 first, but the 10.5" is fun.

[AlanM]

...But if you drill thirty 1/4 inch holes you will have removed the same area as one 7.5 inch hole

I'm still picking up my 20" A2 first, but the 10.5" is fun.

Not EVEN close! 30 .25" diameter round holes = 1.4726 square inches.
One 7.5" round hole = 44.1786 square inches.

If you shot the .25" holes in a circle it would be 2.637" in diameter and if the center fell out the area of the resulting hole would be 5.4628 square inches.

[0ne5hot]

that is what it get for doing math in my head ...still that is going to hurt