Sunday, January 22, 2006

Boomsticks: I seem to have a one-track mind...

Yet more nattering about .300 Whisper.

(If you're not a terminal ballistics geek, this post will probably be as dull as watching paint dry. I won't feel bad if you skip it, but if you've read this far and are of a masochistic bent and wish to read further, I'll try and supply definitions as I go.)


On further reflection, the 220gr loading should make a pretty fair House Gun round. Here's my reasoning:

1) Sure, the bullet is a weak sister compared to rifle cartridges, but think about it: 220 grains, 1040 feet per second, 500+ foot-pounds of energy. Nobody ever accuses the 10mm Auto or .45 Super of anemia, and these numbers would be right at home with either loading.

2) Those 220 grains are in a .308" bullet. That's a lot of sectional density. (Sectional density is mass relative to cross-section.) Sectional density is what makes for penetration in bad guys.

3) The 220gr projectile is of a long-ogive, VLD (Very Low Drag) configuration. This means that it has a long, pointy nose and a center of mass that is well aft. These are the things that cause a bullet to have an early yaw cycle ("tumble", in layman's terminology) on impact. (Basically, this means that the big, long bullet will, almost immediately on impact, yaw through 180°, shedding energy as it does so, and continue on, base-forward, for quite some distance.)

4) Muzzle blast (both noise and flash) out of a 16" carbine, even unsuppressed, is dramatically less for the Whisper than it is for any of the common 5.56 defense loads. This can be important in an enclosed, darkened room.


Discuss amongst yourselves...

4 comments:

Chris said...

As a townhome resident, I'd be concerned about overpenetration if you miss your "target". Some townhomes have a full height masonry wall separating the units, but in ours, that only covers the first floor. The top two floors are only separated by two sheets of drywall and framing studs (like most apartments I'm guessing). I'd stick with expanding bullets in a handgun or pistol caliber carbine (9mm AR hint hint).

If I lived in a single-family unit (NOVA-speak for regular house), I wouldn't be as concerned.

Justin said...

Chris, you might want to take a gander at the Box 'o Truth

Long story short: 9mm, .45ACP, and .223 will all blow right through 12 pieces of drywall (6 walls).

Check it out. Pretty entertaining and enlightening.

Brian (Perfessr) said...

How is that Mauser in 300 whisper shooting...

Homer said...

Thanks, Tam. Hadn't thought of the Whisper in that sense. Time for some research; perhaps a short-barreled carbine similar to the 7615, or a semi-auto in the size category of an M1 carbine. With an ammo swap, might make a decent 150 meter truck gun. Yes, time for research.

Chris: if NOVA means what I think it does (I used to live in Franconia), almost all single family homes in your area are 2X4 stick construction with oriented strand board as sheathing under vinyl siding. Antyhing from .22 long rifle and up will make it outside with no trouble; your 9X19 AR wouldn't know the walls are there.

Solution: put the rounds in the bad guy, where they belong. Practice, practice, practice.