Good question.
I don't have any scientific way of doing it but I take a "before" measurement with my dial calipers, hold the cartridge in question tightly with both hands, put the bullet tip against my benchtop and giver 'er a shove.
I'm not try to hurt my hands but, I feel, if I'm doing it right then it should be...uncomfortable.
Also, making up a couple of dummy rounds and chambering them from the magazine a time or 2 will let you know if there's a problem.
I don't have any scientific way of doing it but I take a "before" measurement with my dial calipers, hold the cartridge in question tightly with both hands, put the bullet tip against my benchtop and giver 'er a shove.
I'm not try to hurt my hands but, I feel, if I'm doing it right then it should be...uncomfortable.
Also, making up a couple of dummy rounds and chambering them from the magazine a time or 2 will let you know if there's a problem.