what's a shot-out barrel look like through a bore scope?

[Cassidy]

If I'm interested in buying a used barrel, how can I tell if it is worn out, shot-out, by looking at the inside of the barrel through a bore scope. I mean, what's a good barrel look like compared with a shot-out barrel when looking through a bore scope?

 

[GSPV]

Get a bore scope and look at a new, clean barrel. Then look at one with a lot of rounds down it. You'll see the throat erosion and fire cracking right away. No problem at all

 

[joejo]

it can be really hard to tell. I have 2 Krieger barrels sitting here chambered in 260. one has a ton of fire cracking in the first 5 inches or so and it still shot 3/4 min. I have another with 900 rds thru it and it looks like new aside from the obvious cracking in the throat area and it won't hardly shoot a 1.5 moa group. I have a 6.5x55 barrel that looks terrible inside but it still holds 3/4 min, I mean terrible!

 

[jonbearman]

The thing about bore scopes is they tell the truth when the seller isnt which happened to me one time.

 

[liljoe]

It won't tell you if the barrel is a shooter or not but you can get a good idea of the round count looking at the first couple inches. If their seems to be some very light fire cracking I would guess it to be around 400 in a PPC. Not sure about other caliber's. If it's still bright and shiney the count is still low.

I just checked a barrel for a guy that said it had LOTS of rounds and you could tell for sure. It looked like a concrete sidewalk in there it was so rough. You can actually see the roughness with the naked eye looking down the bore.

Joe Hynes

 

[K22]

I have a Remington Model 700 in 243 (factory stainless). The barrel looks terrible though a bore scope (throat erosion), no surprise since I got 3,621 rounds through it which is obviously a lot for this over bore caliber.

However this rifle will still shoots under 1 moa with tailored reloads. This is not target grade accuracy but still works for me for hunting applications.

So it depends on your intended use and the amount of shooting you anticipate doing. Unless it's a real bargain and only has moderate throat erosion, I'd pass and go for a new barrel. Perhaps having a experienced rifle smith examine it might give you some sense of remaining life.

 

[RAFII]

It would be really great if anyone has some pictures to post showing what things look like with a bore scope.
As I have never seen it myself...

 

[fdshuster]

RAFII: Although I don't have the camera system for my Hawkeye borescope, these advertising pictures from Gradient Lens shows much of what I see with the 'scope. #1 is just plain copper fouling. I recently looked in a factory 308 barrel that had such long term neglect that the copper colored copper was dark green, like what we see on older houses with copper rain gutters. #2 is an example of a barrel that has little or no value. The surface has holes from where chunks of steel were left after the firecracking became severe. The holes then fill with copper, the reason a worn out barrel will be a lot harder to clean. #3 shows the typical cross reamer tool marks that I see in the vast majority of factory barrels that have not been hand-lapped. These reamer marks being perpendicular to the bullets travel naturally fill up with copper, again making it very difficult to clean. #4 is the throat directly in front of the chamber. This is the first place where linear cracking will form. After that the alligator skin will begin in the leade area, and progress further forward as the number of rounds fired increases. #5 Typical of what I see in a Krieger, Bartlein, Hart, etc. barrel. No comments necessary. The picture says it all!

 

[40X Guy]

Great post Frank!

 

[5spd]

^^ What is stated above. With a scope the 1st thing you will see starting at the neck is fire cracking, no lands/rifling OR so thin you can barley make them out for a bit depending on how much its been shot , rifling not as sharp throughout the barrel etc.