I only have tried to resize my AR 50 50 brass, I hear complaints about the pains of resizing surplus MG brass. Does the same sizing problems occur in semi M2 Brass?

yes

Hmm, I would have thought it might be easier since you get a full lock every shot.

Is it exactly the same, or a little better?

Probably the same as they (the brass)  expand to the size of the chamber no matter how fast there fired

I have had some M2 brass that sized a lot easier than other batches, I think it depends on how well the headspace is set. It is all harder than bolt gun brass though.

Ed

It's going to depend a lot on the rifle it was shot out of.
I've picked up brass from Semi Barret's that sized and worked very well. I've picked up brass fired from M2's that was pretty tough.

The speed the rounds are being fired has nothing to do with it. The stretching and difficulty in sizing brass fired from M2's comes from loose, well worn (and already a bit "loose") chambers, and being poorly timed. Get brass that was fired from two or three different M2's in different states of repair, and you'll find some brass is in much better shape than others...but any way you look at it, it is stretched more than you will find from any bolt action and most semi auto's.

Not sure what you are saying KD. Could you state that again differently?

edit for spelling
sorry sent that last post from my phone

exactly my point

I understand this for a f/a gun, thats why I asked about the semi version since that variable is not there. I guess it depends on the headspace.