Stainless steel tube ID 4.5mm $8

[Felinis]

From a popular online Chinese catalog:

"Outer diameter 12mm, ID 4.5mm, 20 cm hydraulic pipe round lathe chamfered 42CrMo seamless steel pipe. $7.73, free shipping."

Would make a great 8" .177 barrel extension. Right? Wrong - waited two weeks and received a beautiful, crowned pistol barrel extension candidate.

Problem - the inner diameter miced to 4.37mm, not 4.5mm. A .177 pellet will not fit. Return request - "denied without photographs".

So my question here is - what can I do with this tube? Is it deliberately bored to 4.37mm because it was designed to be rifled?

Looks like cutting a barrel starts at $100.

 

[marflow 777]

there no such thing as a barrel extension
and you are going to return 8 bucks worth of tubing back to China really
what can you do with it, throw it the box of things that did not work

how would you put on the barrel extension it would be near impossible no let's make that impossible

 

[ctshooter]

Extending any barrel is a terrible idea. You will negatively impact accuracy under nearly every circumstance.