I think I finally wore out a barrel

[gds]

What about driving a slug down the barrel a few inches then drive it back out. That way you can definitely see if there is ANY rifling left at the chamber.

I just did this.

the one on the left I slugged 2 inches into the bore from the chamber and the one on the right I slugged 2 inches into the muzzle. they still measure .308 however the one from the chamber end has no rifling marks whatsoever.

[afshirt]

Im really curious as to the barrel makeup. Chrome lined? 4140, stainless, etc.

It is just weird to see a barrel wear out that fast. Not a 100% apples to applies comparison but when my shop does the semi annual gauging on our M4s guns with hundreds of thousands of rounds still test perfect.

[gds]

Stainless steel.

I am very perplexed on this. my M4 has way more rounds then this thru it. I have another 5.56 barrel with even more then M4. I have a M1919 I built from a used Israeli Kit with who knows how many rounds thru it. I got M1911 with well over 4000 rounds and 9mms the same. I really don't understand it. The more I talk to people who have shot even more then me, the more I am confused.

I even considered my cleaning practices, but a vast majority of the time I clean the barrel with a bore snake. Rarely does it get a cleaning rod down it.

[talonxracer]

How many rounds worth of flat black powder coated bullets did you end up sending down the tube? I would expect as little as 100 causing significant wear. SS wears faster than CM steel.

You will get a lot better picture of the condition of the chamber throat and initial engagement point of the rifling if you use some Cerrosafe casting material.

[gds]

I figure around 700 or so. but I have put that many thru my 1911 and my 9mm before I switched. Plus it was shooting fine after I stopped using the flat black several months back and have fired a lot of jacketed and traditional lubed cast, as well as powder coated cast from powder by the pound. Plus I have put close to that many with the black harbor freight powder coat thu my model 7 and my 16 300 blk which is also stainless steel but with traditional rifling, with no measurable change and the still shot great. the fact that it will still shoot jacketed fine is very very confusing.

Like I said above. the flat black could be a contributing factor. but this barrel should have not wore out this fast. the more I look into it the more I am really confused. it could be compounding issues.

Part of the problem is I have to kind of guess on the number of rounds. I am trying to base it off how many primers I have used, so it is kind of a guestimation.

[gds]

You will get a lot better picture of the condition of the chamber throat and initial engagement point of the rifling if you use some Cerrosafe casting material.

I have a email into the manufacture. I may still try to get some cerrosafe. either way the barrel is shot

[gds]

I hope these are clear enough to see

this is from the muzzle end. 3 "grooves"



this is from the chamber end smooth bore for at least 2 inches

[fat_mcnasty]

Hey Garry toss it the mail to me and Ill run the bore scope through it and see what the heck is going on.. You might just be leaded all to hell.

[Omega]

That was my first thought, it looks like there is some build up around the grooves.

[plant.one]

before ya ship it, might as well get out the hoppe's #9 (or your fav lead solvent) and brush the hell out of it to check if it IS leaded... if you're piled up that bad a bronze or stainless brush ought to show some evidence of it pretty quickly.