PDW trunk gun quest

[stanc]

I am looking for a "good" personal defense, cr4p hits the fan, trunk gun.

My considerations:

1. 5.56 Nato - I've been told there are windshield penetration problems (true or false?). What round would be best?

Windshield issues w/M855 Ball: True.

Best commercially available windshield/barrier load is probably Mk318, but there are other good factory loadings, such as those with TSX or TBBC bullets.

2. Grendel - what round would be best?

Best windshield/barrier load is AA's 120gr TSX.

3. 5.7mm x 28 - (I currently own an AR57, but am concerned about windshield, metal penetration). I like the 50 round magazines, but the only ammo I have is the -197SR.

Don't know what is the best load in this caliber.

4. 300 AAC Blackout - overkill?

IIRC, there are only two factory loads: 123gr FMJ, and a heavy bullet, subsonic round. I've seen no info on barrier defeat capability of either.

Thoughts?

There is some merit to the "commonly available caliber" idea advanced by LR1955, but IMO it depends on what type of SHTF scenario you envision.

If you're thinking of it being just you, your wife and kids, against whatever "hostiles" you happen to encounter, any caliber will do. That's because one shooter against multiple, comparably-armed opponents, is unlikely to survive long enough for ammo resupply to become a concern. And if you make it SOP to avoid combat, a good basic load of ammo will last quite a while, perhaps longer than the SHTF situation.

OTOH, if you figure on being part of a large group, a common (and preferably, commonly-available) caliber would seem to be a good idea.