Can I cut off the front sight, and leave the gas block, so I can I add a 12 inch free float rail?

Right now it has a 9" non-free float rail

Yes....done all the time. Just make sure to cut above the gas tube.

I did that once. Although I didn't cover it with a hand guard. Looked pretty ugly.

Thanks. Lots of info/Videos on the internet

Looks easy!

DREMEL

Heck you could use a sawzall and an angle grinder on that!

Seriously, wht not if you are covering it.

Done a number of them, cut it off with a hacksaw and smooth it up with a file.
Tought it up with Brownells cold bluing

I bought a used DD rail that came with an unknown manufacture gas block. Low profile. But when the gas port is lined up, the tapered pin isn't lined up with the tapered hole in the barrel☹️

So I'll just grind down the front sight and install it

The easiest way I’ve found to do them is to go ahead and remove it first. The. Use a hacksaw and bench grinder. I just spray mine with black high temp paint.

Did exactly that !
Pretty fun.
My first time!

Gas blocks are cheap...........buncha tightazzes here, eh?

MM

It's better this way.

How better? LOL

I got a couple of spares I'll donate to ya, Blue.

MM

They're held in place with taper pins, which is the most reliably secure way to mount them. A replacement would, at best, use a dimple in the barrel. And that only if you go through the expense and hassle of buying and using a jig for that, which most people won't.

And even without the hassle of the dimple....
I can remove a gas block, work for 15 minutes to grind it, then install a gas block. Cost--$5 for paint.
Or I can remove a gas block, spend 15 minutes finding and ordering and unboxing the new one, then install a gas block. Cost--$30 for a gas block.

You don't save any time.

Yeah, I know all that, but I'm just pullin' yer leg...............it works, but I don't like the looks & as for being pinned, there's lots of pinned GB's available, most notable, maybe, is Noveske.

To each his own.

MM

Wasting, the American way.... use what you got works just fine and there is no flaw in cutting a sigh base off if needed.

The other way you do those if pin holes won't line up and you just have to spend on a new block, take sight off, put taper pins back in with 640 loctite. Cut off each side, file flush with barrel. Then put new block on with set screws it comes with or if just holes, drill and tap holes for set screws. Works just fine

We are talking ARs.. how can one worry about looks? They are ugly to start with.