3 point jam problem

[Corkscrew]

I am having a problem with a series 70 1911 Colt upper on a Para lower. A friend asked me to look at it as it was having FTF issues. I found that the extractor was broken and I replaced it and tuned it. The main problem that I am having is that when the mag has more than 4 rounds in it, it will jam. If it has 4 rounds or less, it will function normaly 100% of the time. From slide lock if I have 5 rounds in the mag it will jam when the slide is released; bullet is pointed up in the chamber and case is stuck on the lower part of the breach, not even touching the extractor. I have tried all the usual fixes, polish breach face, tune extractor, ect but I am still not having any luck solving this problem. The mags are 13 round Mec-Gar and the pistol has seen quite a bit of use but has worked very well for my friend up until recently. I am not all that knowledgeable about the 1911 but have built several FALs, AR, ect. If anyone has any ideas about what may be causing this problem, I would be grateful to hear them as I am about out of ideas. I was thinking that maybe the next place to start would be to replace the recoil spring. Just don't want to spend too much money on this pistol as it is just a shooter grade weapon.

Thanks again!

C

[pa_guns]

Hi

From what I have seen it's not an unusual problem with those mags.

Bob

[John]

Need more details.

Para frames are usually cut for a framed barrel. Are you using one?

[niemi24s]

The mags are 13 round Mec-Gar and the pistol has seen quite a bit of use but has worked very well for my friend up until recently.
Has the pistol's "quite a bit of use" been with these Mec-Gar magazines (during which period the gun worked OK) or did the problem arise recently when your friend began using the Mec-Gar magazines?