can i can down an AR barrel

[fenceline]

shortening below 18"??,the thing is already below 18"..it's 16",in any case,who would ever know if anybody did cut an AR barrel down,after all,,they are available in almost any length you want,so nobody would ever really know,from 16 to 12 seems really easy to do,a quick trip on the lathe and a quick recrown and it's not a factory 12" barrel.i can't see how that would be a problem,

Other than the law...

 

[X-Treme]

shortening below 18"??,the thing is already below 18"..it's 16",in any case,who would ever know if anybody did cut an AR barrel down,after all,,they are available in almost any length you want,so nobody would ever really know,from 16 to 12 seems really easy to do,a quick trip on the lathe and a quick recrown and it's not a factory 12" barrel.i can't see how that would be a problem,

Jesus! Just buy a new freakin barrel, and stay within the law. You just said it yourself. They're available in every length.

 

[Wiskey1]

the law,, funny

 

[kage123]

Just buy a new barrel.

One question however, it says if the barrel has been altered so as to be less than 18".

If it was less than 18 before, then technically it has not been altered to be less than 18". It doesn't say altered AND is less than 18... Thoughts on that line of reasoning?

 

[hbean]

shortening below 18"??,the thing is already below 18"..it's 16",in any case,who would ever know if anybody did cut an AR barrel down,after all,,they are available in almost any length you want,so nobody would ever really know,from 16 to 12 seems really easy to do,a quick trip on the lathe and a quick recrown and it's not a factory 12" barrel.i can't see how that would be a problem,

On a unmarked custom barrel made from a barrel blank there is not really a way to tell, unfortunately you own a Colt 6920 M4 profile barrel it will be much easier to tell.

1. The markings on a Colt barrel is located at the muzzle end, just so happen it is the end you are planning to cut.
2. You will need to replicate the original factory Maganese Phosphate finish to hide the newly machined surface.
3. On a M4 profile the back of the barrel is skinnier than the front, pretty much all the SBR barrels on the market have a much heavier profile because you need it to help dissipate the heat and reduce harmonics.
4. Most importantly Colt don't make a 12" AR barrel.

 

[Sqr]

There are quite a variety of barrel lengths, gas tube lengths, and gas port diameters used on AR-15 type rifles. Gas port diameter will vary not only with barrel and gas tube length, but also with barrel diameter at the port (length of the gas port, so to speak).
When I made my first AR barrel from a blank, I drilled the port undersized, and went to the range with a battery operated drill and a set of number drills. Gradually opened the port diameter until the rifle was functioning properly. That barrel was a 1:8, and shot really well. Eventually used it up.

essorx - there is no such thing as an 80% barrel. The 80% business is US, applies to receivers, and varies according to the whim of the BATFE.
I would suggest that a barrel blank is not a barrel. A barrel may be made from a blank.

Yes there are many barrel lengths but the gas port position and size is matched to the specific gas system. Eg If a mid sized barrel is shortened right up to the port without changing location there will be functioning issues.

 

[Wiskey1]

sure would be nice if we didn't get gouged so much for barrels and BCG in Canada,the stuff i buy in the US is so much cheaper,but i can't legaly take it out of the US,as for gas port location,there seems to be a few different lenghts of barrels with the same location.this one happens to be carbine length,and what happens when you buy a barrel at a show and it's been cut down,?? since you bought the barrel like that and aren't the person who cut it,what then,?

 

[tiriaq]

The law doesn't address who did the cutting, does it? And the barrel is irrelevant until it is on a rifle.
This thread has run its course. Asked and answered.