Buttstocks such as the Vltor, the Magpul CTR, the Sopmod, are they CQB capable? Such as can I beat in someone's face if it came to that?
I beg to differ. A buttstroke to the head or stomach is effective, and I wouldn't drop my M16/M4 to get out a knife instead. It doesn't necessarily mean anything except you probably shot 30 rounds (or had a malfunction), after which you couldn't conveniently remedy the situation because there was too much stuff going on. Not a great situation, but not so dire that you would necessarily have to drop your weapon and get a knife. However...if you had fixed a bayonet, you could use the other end!When it comes to that moment, is it really going to matter?
If it comes down to having to hit someone with your stock something REALLY ****ed up has happened anyway, and you're at a last resort. Your guns are out of ammo, and you've lost or can't get to your knife.
If it comes to that just do it, and if it breaks your stock consider yourself lucky to be alive and worry about replacing the stock after celebrating and thanking whatever God you happen to believe in.