What are these Pointy things at the bore/chamber junction? >>>Edit added information

[hoz53]

current chamber >
ar 15 chamber> reamer print> This is a pic of the leade of a chamber. What are those pointed spike projections going into the bore. this is a chamber I cut and ive had these in another bore with this reamer so im wondering if somethings going on with the reamer or its something else. Or will these hurt anything. Doesnt seem they would help.. Ive never had these things before--they kind of look like they are convex-Any info is appreciated. Thanks. Edit

Ok I’m adding additional info - The original pic was a chamber I cut off. It also had lengthwise lines the whole chamber(see pic1 above) The new chamber and another chamber I cut in a Remington barrel have shorter points, but they both have them. I’ve included pics. Barrel is a green mountain gunsmith blank in 5.56- 12twist. Not sure about # of groves yet. Reamer is an off the shelf Manson in 223 Wilde Caliber with 4 chambers on it. They have all made the points. I’ve included a reamer print to. Thanks to all who have replied.

 

[ridgeway]

Almost looks like the freebore diameter on the reamer barely cut or the reamer was flopping around some. Proper bushing?(can of worms could be opened on the bushing usage debate) Barrel MFG? Could be the bore isn't round too. Kinda hard to tell from just that one pic..

 

[jelenko]

Do those pointy things line right up with the lands? From the pic, it looks like the lands are tapered down. Is that even possible?

 

[Edd]

How many grooves does that barrel have?

 

[Will Henry]

I'm guessing five. WH

 

[Dusty Stevens]

Does it look the same all the way around?

 

[DaveTooley]

Barrel? Reamer specs?

 

[SBLH10]

From the the above picture it looks like a button barrel and the reamers has no free bore.

 

[Rustytigwire]

The pointy things are.
The termination of a groove or land either one by machining a taper into the barrel.
Depends how your eyes are crossed as to whats in or out, raised or depression.
My point is, They being the same all the way around is indicator of good symmetricral barrel and machine work.
That stuff doesn't come out all samey samey unless the guy gets it all just right.
Nice work.

 

[Rustytigwire]

Ok i looked some more.
X is groove, O is land.
The pointy things seem to be a tapering off of WTHeck is that???
Oh and the scratch, crank reamer in after the fact to re measure because i forgot how far it went?

 

[Dusty Stevens]

Its weird that the neck doesnt even clean up the grooves like its the wrong caliber barrel or something.

 

[338 dude]

This is a pic of the leade of a chamber. What are those pointed spike projections going into the bore. this is a chamber I cut and ive had these in another bore with this reamer so im wondering if somethings going on with the reamer or its something else. Or will these hurt anything. Doesnt seem they would help.. Ive never had these things before--they kind of look like they are convex-Any info is appreciated. ThanksView attachment 1188133

Convex would be protruding upward in which case the reamer would’ve cut them even with the chamber maybe they are concave there is a certain brand of AR 15 that has notches in the chamber called E square technology it helps with ejecting the spent case but I cannot remember the name of the manufacturer at this moment .It came to me patriot ordinance factory. POF

 

[clowdis]

No idea what I'm looking at and I've looked at a bunch!

 

[338 dude]

Check out Patriots ordinance factory it is a proprietary chamber and they are the only ones I’ve ever heard of that do this

 

[Alex Wheeler]

Im going to bet its a 5 groove and you didnt use a pilot bushing?

 

[Spotshooter]

Reamer chatter ? By any chance is that a 5 R barrel ?

 

[338 dude]

 

[hoz53]

Reamer chatter ? By any chance is that a 5 R barrel ?

its not a 5r but could be chatter thanks

 

[hoz53]

View attachment 1188221 Check out Patriots ordinance factory it is a proprietary chamber and they are the only ones I’ve ever heard of that do this

thanks for that info- interesting-

 

[hoz53]

No idea what I'm looking at and I've looked at a bunch!

mabie im the only one thanks