Yep, that's the mod I've been trying to explain to folks since as month or so after I got my first P-3AT.
If you "tune" your magazines, cycling the slide slowly forwards and watching the round as it pops completely free of the mag, you can see exactly what effect the extractor is having on the round... the rim should slide neatly into the groove.
Sometimes it's not possible to adjust this via the mag alone, and the extractor needs the mod.
and some cases may not have a wide enough groove to fit the extractor claw into (which explains some ammo sensitivity, a different case may have a bigger groove and not need the mod).
Although I'm still not sure why the extractor claw is commonly forward of the rim when the slide is forward, causing it to sometimes hit the case and be pushed outward a bit. Then when the slide starts to move back, the extractor has to then pivot back into the groove as it comes back to make contact with the rim (and sometimes may not make it all the way in the groove in time to get a good grip). I mean I am comparing it to a 1911 style extractor which has a full grip when the case is seated (it actually pins the case to the breach face). About the only thing I can think of, is that making the extractor a bit long means they don't have to be as precise when making it, and will just work most of the time. But I wonder if a slightly shorter extractor that pins the case to the breach face like a 1911 would cure many extraction problems (but may also require fitting, as many 1911 extractors require tuning).
That's just about it, exactly...
The extractor needs to be tuned to hold the case against the breech. Get it to do that, and half the battle's over!
Problem is, with .380 ammo there's a whole BUNCH of variation on rim thickness, much more than .45 ACP...
So, I've basically adjusted my P-3ATs to fire my favorite defensive rounds, and get perfect performance with them. If it were to malfunction with other brands, I wouldn't care...
A .45 is MUCH easier to tune for, and more forgiving.
I don't even have one yet and already thinking of mods....
Yeah, I'd think variations in rim thickness would be an issue, but also, isn't there some sort of spec for this that cases must meet? I thought there was (but it may be very loose, or maybe I'm just making things up ).
but I don't remember seeing any specs on the width or shape of the groove in front of the rim, so I figured that is where the most variation would be (due to a lac of specs).