Burned Out Barrel

[alberta tactical rifle]

We got this barrel in a few days ago as part of a rebarreling job and thought it might make a good example of what exactly happens to a barrel when it is past its useful service life.

Note the rifling is completely eaten away for about a quarter inch ahead of the neck and the steel is blackened and crispy.

This was an OEM factory barrel. Note the rough chamber and visible tooling marks from what was obviously a dull reamer. Also note how rounded the corners are on the shoulder transition from body to shoulder and shoulder to neck.

Here we see a closeup of the same chamber as above (top) compared to a custom, hand polished match chamber (bottom) cut with a new, sharp reamer. The chamber walls are bright and shiny with no tooling marks and the transitions from body to shoulder and shoulder to neck are sharp, not rounded.

 

[guntech]

You are learning how to take pictures too...

I have a barrel that split in half from the muzzle right through the chamber... I'll have to dig it out and take a look at the rifling and see if it is worthwhile to post a picture.

 

[Paulinski]

Wow - big difference to a custom chamber. Factory = yuck

 

[cjs]

Very interesting, good photos that explain a lot.

 

[griffin86]

O wow thanks!

 

[lord-humungous]

Interesting, now I know what it means when I read an EE ad mentioning a dark barrel.

 

[pilgrim]

how about a pictures of the custom chamber after, let`s say, 2000-3000 rounds? is it going to be the same as on the second picture?

 

[joshledoux]

that is an awesome cutaway

 

[Camo tung]

Enjoyed that, very educational. Not sure I want to peek into mine now.

 

[lister]

Thanks. Good educational pics.

 

[TimC]

great, can I use the pics for a forum over here?

 

[alberta tactical rifle]

What forum and in what context?

 

[BeerBaron]

Thats very cool. The biggest supprize I would say is the roughness and rounded corners in the chamber. Any idea on the round count of the burnt out barrel?

As far as how much of the rifling is burnt out, it looks tought to tell exactly where the rifling would've started. How much of the ~1/4" with no rifling would've been the 'throat' of the barrel/chamber? You would expect that a factory barrel would have a little longer throat than a custom one probably, unless that custom is specifically throated long to allow longer OAL with long bullets.

Either way, cool pictures, I would be interested in seeing more. Thanks for posting them!

 

[MagnumPeanut]

This is so cool, thanks so much.

 

[Goose25]

Thank you

As they say "A picture is worth a thousand words" !!!!

 

[BigUglyMan]

"A picture is worth a thousand bucks !!!!

Fixed it for you.

Sure does show the difference between factory tolerances and those from a custom shop. Did I miss the round count of the cooked barrel?

 

[alberta tactical rifle]

Fixed it for you.

Sure does show the difference between factory tolerances and those from a custom shop. Did I miss the round count of the cooked barrel?

We honestly do not know the round count, but it is high.
Sectioned piece of burned out barrel is off of a LE agencies 308 cal. rifle that we are rebarrelling.

 

[6mm Shooter]

EDIT. I should have read the second page.

I always thought a highly polished chamber causes more bolt thrust and therefor you see pressure signs on the head of your brass earlier.

 

[rem338win]

I shot the barrel out of my .270 and it must have looked something like that. A few thousand rounds of 130gr whatever and 60grs of H4831sc will do that. Kept the 5 thou of the lands until I was so far out there wasn't any chance of getting near the lands. It still shot around an inch.
Cool pics.

 

[bobfortier]

Thanks for this. I suspect my Lee Enfield to be worst than that....ah well