Captain;
Good morning to you sir, I hope the weekend has been a good one for you so far.
As you said, the legal accepted way to measure a barrel here is to drop a rod down it and measure from the muzzle to the face of bolt with the breach closed.
That's sort of clear - but there's of course a couple exceptions - so its only the part of the barrel which the bullet or wad column touches that's considered barrel. A flash hider or brake isn't considered such even if it's been welded on.
Crazy I know, but that's what it is.
A center fire, semi-auto rifle must have a barrel length of 18½" or the metric equivalent to be classed as non-restricted, which meant that M1 Carbines all didn't make it in their original state.
Lastly to add to the confusion - if it's a factory barrel, then a non-semiauto centerfire rifle or shotgun can have a much shorter barrel and still be non-restricted, providing the overall length of the resulting arm is more than 26½".
That's how we Canucks can legally run about in the mountains with 13" and 14" barreled pump guns for bear repellent.
If we cut the barrel down ourselves however, it must be 18½" long. Here's an example of both legal forms of bear scare devices up here.
![[Linked Image]](http://i180.photobucket.com/albums/x83/BC30cal/DSCN5288_zpscyamgchu.jpg)
Again I know its confusing and I hope that helped and didn't cause further confusion.
All the best to you and good luck on your hunts this fall.
Dwayne
