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Posted: 2/23/2009 10:18:17 AM EDT
| I was curious as to what the best method of ensuring a straight FSB. Do most people just eye it until it looks straight? I am trying to avoid as much canting as possible. Thanks! |
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I bought an Armalite barrel with a single rail front sight block. I didn't mess with it at all till I got out to the range. It attaches with two allen bolts. After a couple of sight in shots, I would then loosen the bolts and adjust the gas block for center. Once I got it all centered out, I used some lock tight to tighten the two attach bolts. Now my gas block is perfectly centered. I would say get it on there as centered as possible and fine tune it at the range.
Mutt |
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Well, mine came already attached from the factory. But it was still off a little. I would assume all they did there was attach it and make it reasonably straight using the gas whole as a reference since it was only a barrel with no upper. But no, I didn't use a level. I just eyeballed it and then headed to the range. I fired a couple shots and saw that it was off a little and readjusted till it came in centered. Keep it simple. Just put it on there reasonably straight and work out the cant at the range. I just figured alot of leveling and measuring would just end up out the window the first time I loosened the bolts on the firing line. After that, it was just trial and error anyway.
One of the other things that can affect the cant of the front sight is the notch in the upper reciever. The alignment pin on the barrel extension slides into the notch. If that notch is off 1000th or so, that will really affect the sight alignment. If there is any play at all between the alignment notch in the upper and the alignment pin, you will get clockwise movement of the barrel when torquing the barrel nut. A friend of mine had this exact problem. When centered, his rifle shot off to the right with his sights move as far to the other side as they would go. After retorquing and adjustment of the barrel extension pin in that notch, his sights centered up just fine. But, if you are just using a block with removeable sights, then you should be able to take up any of the sideways cant by moving the block slightly to the left or right. It really doesn't take much movement at all. Hope this doesn't confuse the issue at all. If there are others here that disagree feel free to correct me. I am just speaking from limited personal experience. Mutt |
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