Stainless barrel - should it look stainless shiny in the threads?

[KotKotofeich]

Simple question I think. Can I tell if a barrel I have is stainless by looking at the muzzle brake threads? The barrel is cerakoted, the threads look black. Does this mean it's not stainless?

 

[kawicrash]

...

 

[alberta tactical rifle]

Simple question I think. Can I tell if a barrel I have is stainless by looking at the muzzle brake threads? The barrel is cerakoted, the threads look black. Does this mean it's not stainless?

It could mean that the threads were CeraKoted, OR there is carbon build up on the threads.
What does the bore look like when cleaned?
Most stainless used for barrels is a 400 series like 416 which a magnet will attract to, the same as it does to chrome moly steel.

If it is that important to know, some place on the barrel that is not seen when the gun is assembled scratch through the coating to raw steel and then try cold blueing it. If it blues it is chrome moly if the silver stays silver it is stainless.

 

[alberta tactical rifle]

You could try a magnet. There should be little or no attraction.

The most common stainless steel used for actions and barrel is 416 which will be attracted to a magnet.
The 300 series stainless is non magnetic for the most part but is not used in firearms.

 

[guntech]

Simple question I think. Can I tell if a barrel I have is stainless by looking at the muzzle brake threads? The barrel is cerakoted, the threads look black. Does this mean it's not stainless?

Sorry to repeat but you will have to remove a small portion of coating (I suggest under the barrel close to the action - out of sight) and test the exposed steel with cold blue... if cold blue causes any change in color, it is not a stainless barrel.

Using a magnet is meaningless. All the stainless used in firearms is magnetic.

 

[coyote]

Guntech has it right do the cold blue you will know right away

 

[supernova]

You could use the relief cut or shoulder to test as well if you don't want to put a scratch in the finish.

 

[jonh172]

Why not dab a little in the chamber?
No scratching necessary

 

[guntech]

Why not dab a little in the chamber?
No scratching necessary

Very hard to see what is going on in there when the barrel is attached to the action...

 

[KotKotofeich]

Thank you all for the answers

 

[BCRider]

I've always found that the stainless steels that are still magnetic are only weakly to moderately magnetic when directly compared to mild steel. Is this the case with these 300 and 400 series steels as well? It's not a total black and white sort of test for sure. But if the barrel is even noticeably weak compared to sticking the same magnet to a known sample of mild steel it might still be a valid test. To make this test valid the sample of mild steel would need to be a pipe or section of round stock that is comparable in diameter to the barrel.

Or are these stainless alloys about equally magnetic as mild steel?

 

[guntech]

Stainless barrels are very magnetic.