Stove Pipes

I'm getting occasional stove pipes on the last round when shooting my Springfield Operator. It only seems to happen when using an 8 round Wilson magazine, though it doesn't happen every time.

Can a magazine cause this kind of malfunction? Funny thing is that the stock 7 round Springfield Mags don't cause this trouble.

How can you have a stovepipe on the last round? is the gun not locking open on the last shot? (that would be your problem!) or did you mean to say next to the last shot?

Correct. The slide is not locking back on the last round fired (the lat round in the mag) and the ejected shell is getting caught up like a stove pipe.

The ejection pattern is different on the last round in many pistols, and they must be getting caught because of short stroking.
Are you using light loads?
Heavy springs? (Mainspring or recoil spring)
Recoil buffers?

One common cause of a last round only failure to eject is poor extractor fit.
The previous empties, just barely hanging under the extractor, have the next round in the magazine to guide them back to the ejector. The very last does not, so it goes in funny directions, sometimes not even out of the port.

The gun is a stock Springfield Operator. Shooting Federal Classic HPs and Federal American Eagle...both 230gr loads. No springs have been changed as the gun is still under 1000 rounds fired. Given that it's happening inconsistently I'm not sure if I should send it back to Springfield or wait.

Is there anything I can do inspect/test the extractor myself?

I had an MC Operator, and i broke an extractor at 3,500rds, and it seems that you are having issues too. makes me glad that i parted ways with mine.

since it is doing it with the aftermarket mags, but not the factory mags that is kinda strange, and that would make me think that the issue would be the mag.

If it's only happening with that 8 rd. mag it is almost certainly the mag spring has weakened and is not getting the last round up fast enough. A rough or tight extractor can make it worse, but if your 7 rd. mags work 100% the extractor is probably within specs. 8 rd. mags really need an extra power spring if they are used with a full 8 rounds all the time. Squeezing that last round in there overcompresses the spring. (and the follower) The 8 rd. mag is a design compromise. I have never had any problems using 8 rd. mags if I only load 7 rds. in them.

John Browning designed the 1911 for 7 round magazines inside that particular length grip housing. Eight is really pushing it but, as we all know, a LOT of times the eight round magazines DO work . . . em . . . MOST of the time.

Many wise people though carry only the seven round magazines in their 1911s when it comes to loading their weapons to protect their bacon . . . and for very, very good reasons.

Just because a Wilson magazine fails should not surprise anyone . . . they are made by humans too . . . with no magical pixie dust. Wilson understands the limitations of the 8 round magazines and makes a FINE 7 rounder too, IIRC.

Ditto using seven round compact 1911 magazines in the compact grip guns that are made to use the SIX round magazines RELIABLY.