I have had 5 different 1911's in 45 ACP. Have swapped all of the mags to the point I don't know which belongs to what gun. Never had any issues.
I'm not trying to be cheap. just frugal. Sig wants $30 per mag, plus shipping. Just seems a little high to me.
Going to the range Tue. Nice gun store too. I'll be asking those guys for their op.