Mod 67 E 12 guage barrel?

I came up with a mod 67 12 guage that somebody has cut the barrel down to 18.5 inch.

Is the barrel threaded in? does anybody know if the barrels from Numerich already have the extractor cuts? Not real happy with the short barrel and would like to replace it.

Thanks, Steve

bump

The numerich barrels should be finished drop in barrels and if you go to their site you should be able to tell is it is threaded or whatever. I almost think they are interupted threads and you turn the barrel a half turn and out it comes.If you talk to someone there like a tech they will probably tell you.