What should I do with this thing?

[Hammer_Man]

Exactly how precise do you want to get? I only ask because the 18" FN barrel (if it's the 18" CHF that I think it is) isn't the most accurate barrel out there. Is it accurate enough to make combat effective hits out to 300 - 400 meters? Yes it is, but will it produce sub MOA groups at those distances? I'm not entirely sure it will, as precision shooting wasn't what it was made for.

[Circle_10]

Yeah I'm not really trying to build a precision AR, and I don't think the suburban and wooded environment around here really calls for it, I mostly just wanted something with a bit more range and accuracy potential than I've got now. The big question was whether it was better to modify what I already have or start over with a new upper.
Since I've already got the FN barrel it makes the most sense to use that, and with the distances the gun is most likely to be used at, it will probably be sufficient.

[Hammer_Man]

Yeah I'm not really trying to build a precision AR, and I don't think the suburban and wooded environment around here really calls for it, I mostly just wanted something with a bit more range and accuracy potential than I've got now. The big question was whether it was better to modify what I already have or start over with a new upper.
Since I've already got the FN barrel it makes the most sense to use that, and with the distances the gun is most likely to be used at, it will probably be sufficient.

I've used the 16" CHF FN barrel on multiple builds, and had great success with them. If you chose your parts wisely you can build a functioning upper for a very small additional investment, probably $300 or less.

[Circle_10]

So I'm looking at low profile gas blocks and I notice that most of them, even BCM's, seem to be the set screw type. I had thought that set screw gas blocks were kinda iffy, but are they pretty much the standard for low profile ones?

[jsbhike]

Get a large ballpeen hammer, large diameter punch(or a punch divoted for the taper pins), and a block of wood on a solid surface (concrete floor) and see if they will come out before making your decision on a rail. Should pop out unless the front sight was phosphated on the barrel.

[26 Inf]

So I'm looking at low profile gas blocks and I notice that most of them, even BCM's, seem to be the set screw type. I had thought that set screw gas blocks were kinda iffy, but are they pretty much the standard for low profile ones?

Pretty much. Most folks dimple the barrel and they are fine. The Giessele blocks are set up for both. These are the ones I prefer: https://algdefense.com/carbon-steel-gas-block.html ($39.99) the stainless steel is twenty bucks more: https://geissele.com/super-gas-block.html

The instruction on the links should walk you through dimpling any gas block (drill sizes may vary).

[MegademiC]

Or you could hacksaw/dremmel and file/sand the existing gas block in place, and spray a little high-temp paint on it... then you have a pinned gasblock.

[ABNAK]

A properly shaved and dressed FSB is the most sturdy low-profile gas block you can have. It's already on there and is already pinned.

[titsonritz]

Or you could hacksaw/dremmel and file/sand the existing gas block in place, and spray a little high-temp paint on it... then you have a pinned gasblock.

A properly shaved and dressed FSB is the most sturdy low-profile gas block you can have. It's already on there and is already pinned.

If you want a LPGB on your existing barrel, this is the correct course of action.

[Achilles11B]

Have you tried other ammo with it? Other match offerings may get you better results.