Second to last round fails to eject

[peredehuit]

I’m reloading .45acp using 185grn copper plated round nose bullets. I use CFE as my powder (7.3 grns). I’m shooting my rounds out of a Springfield Government 1911. It has a 10lb recoil spring. I also use Wilson Combat magazines. Everything cycles perfectly except the second to last round. It always fails to eject. It can’t be by accident. What am I missing?

 

[kingaling]

Never had that issue but if I had to guess I'd say the last round in the magazine is sitting at a weird angle causing the slide to not come back properly since it's always the second to last round.
Tried different magazines?

 

[RegionRat]

Check the lips on the magazine. Test a few others and compare dimensions to learn how to tune those mags.

If you fail to correct this with the mags, you should seek out a bonafide 1911 versed gunsmith.