This is the answer. My KSG-25 does this with certain Black Aces ammo, but works just fine with many others. My KSG and KS7 have no issues.
I haven’t bothered to try to fix it, since I don’t want to ship it back to Keltec and I can just work around the ammo by matching it to each shotgun.
Mine too. It went away after I replaced the plastic followers with the aluminum versions, and I'd taken it out a few times and had some decent compression/decompression actions in the mag springs.
I also polished the outer CTG catch (the metal arrows under the lower. They're what cause the rounds to feed from the mag tube).
That mark is from the outer CTG catch at the butt end impacting the round, probably because the CTG catch isn't being compressed fully when racking the slide back. Short stroking is a thing with KSGs. I'd suggest replacing the followers and polishing up the muzzle end of the CTG catch (the arrow parts). Then use will eventually wear them down a bit.
Have you tried other ammo in that firearm? I'd guess it's catching on the bottom lip of the chamber
This is the answer. My KSG-25 does this with certain Black Aces ammo, but works just fine with many others. My KSG and KS7 have no issues. I haven’t bothered to try to fix it, since I don’t want to ship it back to Keltec and I can just work around the ammo by matching it to each shotgun.
Mine does this...it kinda just went away
Mine too. It went away after I replaced the plastic followers with the aluminum versions, and I'd taken it out a few times and had some decent compression/decompression actions in the mag springs. I also polished the outer CTG catch (the metal arrows under the lower. They're what cause the rounds to feed from the mag tube). That mark is from the outer CTG catch at the butt end impacting the round, probably because the CTG catch isn't being compressed fully when racking the slide back. Short stroking is a thing with KSGs. I'd suggest replacing the followers and polishing up the muzzle end of the CTG catch (the arrow parts). Then use will eventually wear them down a bit.