I think it is tool chatter. If you look at the pictures above that barrel is new never fired stored. The only thing ever sent down the tube was the camera.

They must use a lot of pressure on the bit to drill/punch that flash hole. Looks like it always leaves a burr. Now I'm wondering if it's intentional to have better ignition by diverting the flame. BTW I will be ordering one of those cams too.

Stock at both Amazon and Bravolink just went up :biggrin:

The thing that surprises me is they don't center the hole on all of them. I have a couple that are centered and the rest are just off to the side. I like being able to check the condition every now and again. I found the link to these cameras on another ML web page. I thought for 20 bucks I could not go wrong. Ron

You could be right Ron, but most modern processes are using TiCn (titanium carbonitrate) coated spade drills with "through coolant" capability for applications such as deep drilling. Possibly the spade insert needed to be changed and the operator ignored it or the programmer didn't add a few seconds of dwell in the program segment prior to retracting the drill once the final depth is reached. It's all about time and money with regard to manufacturing costs and they probably figure the average guy isn't gonna spend any money on something to look down his barrel with as long as it performs as expected.

BPS

And they do perform as expected. Ron

Yes Ron, you're right. As long as the performance is there, who really cares if the bottom of the breech is a little scarfed up? It has no affect on the barrel's performance seeing as how it's at the bottom, but it could collect and hold residue that could cause rust to start if the owner doesn't do a thorough cleaning. That's why I'm a firm believer in "flushing" a closed breech barrel VS just swabbing them clean.

BPS