I have a pre 1994 Eagle lower in which original Pmags are a tight fit. I emailed Magpul about it and they said they were designed for Colt magwells and that newer generations would fit a greater variety of lowers.
I just took a sanding block to the front of those Pmags until they dropped out smoothly. It really didn't take much work.
God gave you a soul.
Your parents, a body.
Your country, a rifle.
Keep all of them clean.