Acceptable for m4 Barrel Extension?

[Georgezilla]

This barrel's m4 extensions have a ring that comes out past the barrel's chamber. It loops around most of the extension and under the chamber, like a helix.

I'm guessing this helix is a thread cut used to attach the barrel. My concern is that none of my other AR barrels have this exposed, rather large, possible thread. Seems like a good place to trap dirt and abnormal compared to my other barrels.

Do you guys think this is an issue of concern?



Thanks.

[Bullseye]

I don't see these marks as being harmful as long as everything measures out properly. If the chamber and barrel are in good order you should be fine.

R,
Bullseye

[Georgezilla]

Thanks, BE. Like I said that cut looks like it's some sort of thread used to attach the extension, but I wanted to make sure it wasn't an issue before I put it on the upper.