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Posted: 12/31/2009 5:25:18 PM EDT
| Where can I buy a front sight tower? Not the flip up type, but the old school fixed iron triangle tower. The style that fixes directly to the barrel. I saw that BCM has one for sale for $29.95...but it is not complete. It requires some gunsmithing. |
| Not an easy project unless you have access to a machine shop. Pinning requires reaming your barrel while keeping the front sight base lined up during the process. If your barrel has already been reamed, you probably will not be able to reinstall a front sight base. They (barrel/FSB) are like finger prints to an extent and finding an FSB that lines with the existing cuts in the barrel are slim to none. |
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Quoted:
Not an easy project unless you have access to a machine shop. Pinning requires reaming your barrel while keeping the front sight base lined up during the process. If your barrel has already been reamed, you probably will not be able to reinstall a front sight base. They (barrel/FSB) are like finger prints to an extent and finding an FSB that lines with the existing cuts in the barrel are slim to none. I guess I am confused now...I was under the impression these style sight towers are clamp on. I guess there is much more to it than that. |
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(I typed this before CAC01 replied, but didn't feel like retyping it. Sorry if it's a little repetitive.)
If you want it pinned they all require gunsmithing (except for those willing to take on a DIY job). They are one part that isn't interchangeable. The FSB is put on the barrel, lined up, then drilled and pinned so they are uniquely matched to each barrel. I think the going rate is about $90 to have your FSB pinned to your barrel. An option is a clamp on FSB or one that uses set screws. Of course these are not necessarily as strong as the pinned. DEZ Arms had one that uses five set screws. JP Enterprises makes a clamp on, but it has an adjustable gas port and it is machined - looks more modern than a regular FSB. This is why I don't chop down pinned FSB's for gas blocks. They make good, strong gas blocks, but once you chop the FSB you can not replace it just by getting a new one and lining it up with the existing holes. In other words, for me, a cheap gas block is better than ruining the pinned FSB. Also, if I'm buying a barrel and it has the option of pinned FSB or set screw gas block for the same price I will go with the FSB even if I intend to use a gas block. |
| The Armalite is the only one I have seen. I recently bought one from DSG and returned it. It is not "F" height and the casting was terrible - but it would work. I went with a five set screw because it's temporary on the rifle I was putting it on. Hopefully someone will point you in the right direction. I'm interested, too. |
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Quoted:
The Armalite is the only one I have seen. I recently bought one from DSG and returned it. It is not "F" height and the casting was terrible - but it would work. I went with a five set screw because it's temporary on the rifle I was putting it on. Hopefully someone will point you in the right direction. I'm interested, too. Thanks very much...do you have a link for the Armalite tower? I can't find it on the web site. |
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They are out of stock. I think they ran about $45. If you want give them a call, they might have the one I returned. It was in the past couple of weeks.
DSG - Armalite FSB |
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Here is a thread with a tutorial: http://www.ar15.com/forums/topic.html?b=3&f=123&t=470461
The clamp on FSB could be made by drilling and tapping holes in the FSB below where it intersects with the barrel and splitting the base longways through the legs to provide a gap for tightening. The "F" is a little taller from the top of the barrel to the shelf, .040 to be exact. It's a long and often misunderstood thing. Basically on some flat tops with a carbine length gas system you will need the "F" height FSB or a taller sight post. It doesn't really matter with A1/A2 uppers, midlength gas systems or rifle length gas systems. If you are using a flat top with a non "F" try it to see if it works. If you can't get the POI low enough without the sight post unthreading all the way buy a .040 taller sight post from Bushmaster. |
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