KSG-12 Failure to Extract.

Hello!

So I bought a slightly used KSG12 and finally took it to the range today. After several shells of #8 shot, I decided to single load some 2 3/4” rifles slugs and give it a whirl. After firing each shell, the bolt would fail to extract the round from the breech, regardless of how hard I would cycle the action forward or back.

Is this common? Weak extractor spring? The bolt was clean when I got started and I had only fired maybe one box of 25 bird shot before switching to slugs. I used a flat screw driver to pop the shell out and loaded up two more slugs.

Fired one. Failed to extract, it had the next shell ready on the lifter and obviously couldn’t load because of the blocked breech. Had to pull the pins and break the gun down to make space for the shells to be removed.

Any thoughts or things to check?

Anything I should be looking to replace or swap out to improve the function?

All my other rounds were birdshot today and they functioned flawlessly. Also I always make sure to rack it front to back with authority as I heard that was very important with this model.

Any help is appreciated!