I want to find a FSB with set screws that can be easily detached if needed. I had a few questions about these, since I have no experience with them.

1. Does anyone aside from Fulton Armory sell them?

2. Where do the set screws attach?

3. Are they as stable and solid as a taper-pinned FSB?

4. Will removing a pinned FSB and replacing it with one that uses set screws cause a problem with the holes in the barrel where the taper pins were?

I should add that I am looking for one with a bayonet lug on it.

SilverC,

I'm new to ARs, but hope I can provide a little help.  I have a Fulton Armory upper with a set-screw FSB.  What I can tell you is this:

The Fulton models have 4 set screws, in the same place where taper pins would be on a regular FSB.  Mine take a 3/64 allen wrench.  I noticed my sight base was just slightly tilted, so I loosened them to align it.  Started by trying only 2 screws.  Thought I had them loose enough, but FSB wouldn't budge.  Loosened a little more - still wouldn't budge.  I had to loosen all 4 of them to the point where they would spin free, then I could adjust the sight base.  I've since re-tightened them and tested by trying to pull on the FSB.  It will not move at all , so I think they probably hold very tightly.

I'll be shooting the rifle next weekend for a better test, but I really don't expect the FSB to shimmy at all.

Hope this helped a little.

joe l.

Quoted: 1. Does anyone aside from Fulton Armory sell them?

Post-ban Armalite rifles used them standard.  All they really are is a regular FSB with the holes tapped for set screws.

2. Where do the set screws attach?

They attach to the FSB and press against the barrel.

3. Are they as stable and solid as a taper-pinned FSB?

Not even close.

4. Will removing a pinned FSB and replacing it with one that uses set screws cause a problem with the holes in the barrel where the taper pins were?

I should add that I am looking for one with a bayonet lug on it.

Why?  Set screws are nowhere near stong enough to support a bayonet strike.

The purpose of a set screw front sight base is when you're building a high end match rifle and don't want to risk reducing accuracy due to stress or deformation in the barrel steel when the taper pins are drilled and installed.

I was actually looking for something that closely resembled the standard FSB but wasn't such a PITA to remove in case I wanted to put on a FF Rail System or something similar.

Would the set screwed FSB serve this purpose? I am not going to war with the gun so even if it doesn't secure to the barrel as well as a standard FSB, I would still be happy with it.

Quoted: I was actually looking for something that closely resembled the standard FSB but wasn't such a PITA to remove in case I wanted to put on a FF Rail System or something similar. Would the set screwed FSB serve this purpose? I am not going to war with the gun so even if it doesn't secure to the barrel as well as a standard FSB, I would still be happy with it.

The pins are not at all difficult to remove if they're installed correctly to begin with.  And with taper pins it is easier to put the FSB back on after installing th float tube.  If it has taper pins you just line up the holes and insert the pins.  With set screws you have to be careful to line it all up correctly so that the gas ports line up correctly.  Let the FSB be tilted a little to the side or be too far forward or back and you're rifle won't get enough gas in the system to cycle correctly.