Ejection pattern of the M1A1?

[HDSledge]

why would a carbine ejection pattern be different in a M1A1 stock vs. a regular stock?

I have no idea since I have never fired an M1A1 before. That is why I asked the question. To see if they are prone to throwing brass back at the operator should he be a lefty. <0

Edit: after watching your excellent historical video I can see that they eject almost laterally and out a foot or two. No worries.