AR Front Sight Block holes dont line up( Fixed it , I think)

[BRIGUY]

The FSB taper pin holes dont line up with my barrel notches . It is obviously a different FSB than what the barrel came with . The hole closest to the reciever lines up perfect and the gas holes line up correctly , but the hole closest to the end of the barrel is about 3/32 off line . I know everyone will tell me to buy another fsb and try that ,but there is no way to tell that one will work either. Should I take a little bit more out of the barrel ?

 

[LoginName]

Are both the tapers pins facing the right direction?

The FSB is timed/mated to the barrel at the time of manufacture.

It's highly unlikely that purchasing a new FSB will line up correctly and fix the problem.

Removing any metal from the barrel might work along with redrilling the FSB and using an oversize pin.

There are undrilled blank FSBs available, but need the expertise of a competent AR gunsmith to install correctly.

One option is to purchase a FSB that is secured with allen screws and loctite.

Another is tohave someone weld/silver solver solder the misaligned barrel cuts, then redrill it to align with the FSB (if that's something that can be done).

If your AR has a permanently attached muzzle brake, it will have to be removed before any new FSB can be installed.

 

[icyclefar]

One option is to purchase a FSB that is secured with allen screws and loctite.

That's what I would do, assuming it is not a simple misplaced pin issue.

 

[Rob Boudrie]

When I took the AR15 armorer's course from Armalite, the instructor told us that the holes are drilled in the front sight tower and barrel at the same time. He recommended use of a clamp-on rather that pinned front sight tower if you are replacing it, since it's virtually impossible to get one with an exact lineup of the holes.

 

[DoubleA]

That is interesting, because I was at a dealer and he pointed out that you could always remove the front site tower and opt for a clamped gas block/front iron sight, but always with the risk that the clamp could become bumped.
I have a greater appreciation for your Armalite Instructor.

BTW, I need a craftsman who can silver solder a muzzle brake (Post-ban work).

When I took the AR15 armorer's course from Armalite, the instructor told us that the holes are drilled in the front sight tower and barrel at the same time. He recommended use of a clamp-on rather that pinned front sight tower if you are replacing it, since it's virtually impossible to get one with an exact lineup of the holes.

 

[BRIGUY]

Well I tapped all the pin holes and also underneath the sling swivel , with a 10/32 thread tap and put set screws with some red loctite . I dont think this thing is moving considering it is tightened down in 5 locations. I will get some pics up , to see what you guys think.

 

[BRIGUY]

 

[KMM696]

Well, if it's good enough for White Oak....

It looks good - I'd make checking those screws part of your cleaning routine, at least for the first 1k rounds, but that's some clean looking work there.

+1 to you!

 

[icyclefar]

Nice work

Show off ;-)

 

[BRIGUY]

Nice work

Show off ;-)