Bore Flaw.

[SMITHTON]

Looking in 223 barrel and seen clusters of steel that looks like a scab. It can not be removed, even with emery paper. had another 223 the same. The throat on both barrels are fire cracked badly. My barrel, I tried Iosso, no go, sand paper, no go. the clusters are toward the mussel end. The scabs are steel, but where from, throat, not cleaning after the gunsmith has done his work?

[Josh Cox]

Sorry to hear this, which brand of barrel ?

[Brad Y]

Im worried that you put something as abrasive as emery paper down a barrel! Best thing to do would be get a gunsmith to borescope the barrel. It could be rust, but if so should be easily removed. Odd one for sure. Firecracked barrels dont necessarily mean they wont perform but you will need to keep ontop of throat maintenance. Iosso in the throat might be better than up near the crown.

[johnk]

I have seen one or two barrels in the past where an "inclusion" popped out after a certain amount of use. In those instances, it presented as a preexisting component of the barrel, not something taken up by the rifling process because the crater had a "torn" surface. Inclusion=apparently differing material composition.

[DaveMc]

Smithton - the fact you have two barrels with same marks immediately makes the chance of it being a barrel flaw almost impossible (They are very rare - say for arguments sake 1/1000 (which I doubt) to have two would be 1/1000*1/1000 = 1 in a million chance.

Being near the muzzle also basically can't be the smith leaving stuff in the barrel (although it is your responsibility to make sure the barrel is clean before firing).

Unfortunately it sounds like you are getting shit down your muzzle somehow (maybe in bag, gunsafe or even just in shooting) and it is marking, rusting or scoring the barrel somehow. You should patch out your rifle before every shoot to avoid these things. As discussed in one of the previous threads I even think constant shooting in dusty environments wrecks the last inch or two of bore requiring more crowning work..

[SMITHTON]

Thanks for the replies. One barrel , the sand papered one, that I gave up on was to confirm it is steel welded in there. The other, not mine, is another make. It has multiple clusters. I will have to cut a section out to confirm. My barrel that is.

[RDavies]

I have seen one or two barrels in the past where an "inclusion" popped out after a certain amount of use. In those instances, it presented as a preexisting component of the barrel, not something taken up by the rifling process because the crater had a "torn" surface. Inclusion=apparently differing material composition.

A few years back I had a barrel which was good when it was new, but after a few hundred rounds developed a bad bunch of pits from 1/2 to 2/3rd of the way down the barrel. All I noticed was that the bullets started to blow apart and that patches really got stuck hard in the middle of the barrel.
While I didn't have a bore scope at the time, someone who did checked it and told me it had developed bad inclusions from a bad batch of steel.
It seems this porosity or inclusions are not there when the barrel is new, but come out after some use.