There is a line of thinking that proposes right-handed bolt actions are easier for left-handed people to use. That's bullpucky. I shoot left-handed and have operated right-handed bolt guns before. Whoever thought up that steaming pile has been smoking too much of their own product. However, many conventional right-handed semi-autos are in fact just as convenient, if not more so, for left-handed shooters.
Take the AR, for example. The safety can be a problem but it's a small one. You just have to drag your shooting hand thumb around the grip to flip it down, unless of course you have an ambi safety, then you're golden. The mag release is easily manipulated with the support hand thumb, and the bolt catch can be pushed with the firing hand index finger, if you have big enough hands. The charging handle is equally inconvenient for everyone. I never had trouble keeping up with right-handed shooters operating a standard AR left-handed. And when doing IA drills, I quickly discovered that having the ejection port on the right side of the weapon as a left-handed shooter gave me a distinct advantage by allowing me to quickly check my ejection port for manfunctions. While right-handed shooters have to cant their weapon in all sorts of funny directions, I barely have to move my head and don't have to move the weapon at all to check for malfunctions, and clearing malfunctions is easier too. So when Stag introduced their left-handed AR line, I thought "Sweet, now right handed people have an AR too." As long as the rifle has a case deflector, the AR does not represent a problem for left-handed shooters in its standard configuration.
Rifles like the AK and M1A, with reciprocating charging handles located on the right side of the weapon are often easier to left-handed shooters. The safety on the M1A is ambi by default. The safety on the AK is on the right side of the receiver, under the ejection port. So again, it actually is easier for a left-handed shooter. As with operating the charging handle, a right handed shooter either has to cant his weapon severally and/or bring his support hand over or under the receiver, or remove his firing hand from the grip, to manipulate the safety. Neither is preferrable to the lefty method which simply involves bringing the support hand back and flipping the safety down with the support hand thumb. Both the AK and M1A can be easily charged by a left-handed shooter without removing the rifle from the firing position, or removing or altering the firing hand grip. And both these rifle have ambi paddle style mag releases. Since both these rifles eject spent casings between 1:30 and 3:00, they present no problems for left-handed shooters.
gun shop guys told him he would have brass tattooing (sp) his forehead
Typical bloviating from a standard "behind the counter moron" that just likes to hear himself speak. I've shot literally thousands of rounds from like easily half a dozen different AKs and never had a single ejected brass hit me. In fact, I can't recall ever having one even flung remotely back in my general direction.
I have little experience with the FAL and G3 other than handling a couple of them. Those designs both seem like they could present problems for left-handed shooters due to the orientation of their controls, but who cares, cause we have a better battle rifle than both of them in the M14/M1A.
The only firearm I've ever had hit me with its own ejected brass (aside from shooting the SAW left-handed) is a Desert Eagle .50 AE while being shot one handed. So as long as the controls can be manipulated, namely the safety and charging handle in my experience, most semi-autos present little to no problems for lefties as they are.