Have a form 1 and an wondering what the best way to cut down my 870 barrel? Its a 12g non-vent rib barrel.

If you're near Houston take it to Vanden Burgs

Dallas

The best way is to simply buy a new 14" Remington barrel.

Any competent gunsmith can do it.  Even incompetent ones can probably do it.  I had a shop do it a few years ago for $40 which included relocating the bead.  I am sure ADCOfirearms would do it as they already cut rifle barrels.  It definitely isn't out of their capacity to do it.  

I will soon do a Form 1 on my Remington 870 as well.  I am tempted to cut & crown the barrel myself.  Brownells sell that crowning tool.  I figure I can hacksaw off the barrel and file to square it up.  Then use the crowning tool to finish the barrel.  Some cold blue and I am good to go.  I already have a clamp on ghost ring front sight, so I don't need to remount a bead.

I used a bandsaw, a file, and some cold blue.  Bead....I don't need no stinkin' bead.

Quoted: The best way is to simply buy a new 14" Remington barrel.

Would love to get if it didn't cost so much to begin with.
And am looking to go about 12.5" not 14".

Cut with a dremel, squared with a belt sander, finished by hand. Cold blued, and then sprayed.

That's pretty sharp, I haven't seen a vent rib done like that.

Quoted: That's pretty sharp, I haven't seen a vent rib done like that.

Neither had I, and since I have a penchant for unique flairs on my project guns...