Barrel extension idea

[12Pump]

I thought of an idea recently. Since AR barrels are already threaded to accept parts such as a supressor or muzzle break, then why not a barrel extension to increase barrel length without having to remove the entire barrel and install a new one (which would also cost much more). If a person had a 16" barrel and wanted a 20" one, they could buy a 4" extension and simply thread it on to the existing barrel. If they wanted a 24" barrel, then they'd buy a 6" extension. Why isn't there something like this already?

BTW, I googled "ar15 barrel extension" and it came up with something completely different than what I'm describing.

 

[rcmodel]

They aren't available because it wouldn't work.

How do you propose getting the rifling lands and groves to line up when you screw it on??

Even if custom made and fitted to an individual barrel, the threads would soon wear to the point the rifling wouldn't match any longer.

rc

 

[wally]

How would you make the rifling line up?

Deal with the potential gap from a rebated muzzle crown?

Not really very practical.

 

[12Pump]

Yeah, I guess I didn't think about the rifling not lining up. I had thought about the different twist rates and that extensions could be made with ones that were the same as the barrel, but then the groves would still not line up.