Bump
Black's best response to the Caro-Kann Bayonet Attack?

I thought this (with Nc3) was one of the older lines (still respectable of course) and like Fezzik didn't know it had a name other than the Nc3 caro.
Bg6 is probably the most principled try with Bd7 as a secondary (solid but less testing). I don't see the benefit of Bf3 to force f3.
The e6 sac is a theme in the opening when you can exploit those light squares like g6 and f7. If I remember though playing it right away is wrong. If black had already played h6 for example it's probably good (after e6 & Bd3 you're coming in).

Schandorff recommends Be4 "Provoking more weaknesses in the white camp" followed by f3, retreat to g6, and if white tries h4, ...h5 is the reply.

My choice would be 4...Bd7. No human or computer has ever played this against me, and the Bd7 idea seems the most flexible after White has weakened the Kingside in this way. Best wishes, Tony Blades, club player & coach.

4.g4 Be4 5.f3 Bg6 6.h4 h5 meeting e6 with Qd6 is the easiest route to equality/slight Black advantage.
Well actually, white doesn't have to play 5. f3 in response to the Bishop move--Houdini seems to prefer 5. Nf3 for white instead, followed by Nd2 to chase the Bishop away.
The 5. Nf3 line is possibly worth exploring further...hmm...

Be4!
If white plays 5. f3 then the weak f3 pawn could potentially become a target later in the game.
if 5.Nf3 then black should also retreat the bishop to g6 to anticipate 6.e6!

There is no point in retreating the Bishop if white plays 5. Nf3, as it only wastes time and tempii.

Interesting discussion. After the moves 1.e4 c6 2. d4 d5 3.e5 Bf5 4.g4!? Be4! 5. Nf3!? e6 6.Nbd2 Bg6 7.Nb3 the position quite resembles the French Defence, only with the White Bishop out of the chain instead of locked. This plan shouldn't give Black any problems and I do think the g4 pawn can be a problem for White if Black counters with h5 at some point.
I would say 5.f3 is the best way to handle this position, forcing the Bishop to move again and then continue with 6.Ne2! (instead of 6.h4 to avoid 6...h5! 7.Ne2 hxg4! 8.Nf4 Bh7!? when the Bishop can move away) e6 7.h4 h5! (attacking the pawn weakness) 8.Nf4 when Black has either the drawish 8...hxg4 or the interesting 8...Ne7!? with chances for both sides.

What about delaying the deployment of your bishop in order to prevent the d1 - h5 diagonal being open for their Queen to torment you? In stead what about 3...Nd7 4.Nc3 Nb6 5. Nf3 Bf5 or 5...Bg4? Now their own knight will block their Queen, and g4 doesn't work anymore because you can simply take it.
Thoughts?
Move 4 is the critical decision point for black. In my meanderings about, I have seen three different main responses to 4. g4
4. ...-Bg6 (the direct retreat)
4. ...-Be4 5. f3-Bg6 (making white interpose f3 before retreating the Bishop)
4. ...-Bd7 (a few grandmasters have played this move as well)
The first two lines give white the option of sacrificing with the e6 push (to punch holes in black's position), while the third option takes away the Bishop's influence in the center.
Any ideas on what the best choice really is for black? And maybe more importantly, are any of the options clearly inferior to the others?