Tru Glo sight install ?

[Izzyjoe]

I recently purchased a Tru glo Tru bead sight for my 870sp, I'm not sure about this front sight installation. The factory bead doesn't seem to want to unscrew, and the vague instruction say some models are pressed in, and have to be drilled and tapped. So I guess I'll get my vice grips and pull the bead out, but my question is what size tap do I need, it seem they have sent several different screws to install the front sight, and is that screw the only thing that holds it on, if so I think I'll super glue the rear part, cause that won't last long with me, I'm not rough on equipment, but stuff happens!  The rear sight is a no brainer, I'm going to install the ghost ring for the rear, it just seems to suit me better.

[dirt road ninja]

Can you post a link to what you bought? I'd like to look it over before I offer advise.

[Izzyjoe]

Sorry, I don't know how to do that, but I bought it at Midway USA, it's a TruGlo trubead turkey xtreme, part# TG950XD.

[SumToy]

it don't screw out it press in.  Now that sight I think you will need to drill and tap a hole for front.  Now Williams and tru glow make a set that clamp on the rib. 

[dirt road ninja]

From what I see Mr. William is correct, I found this list of thread size and that may be helpful when looking at a drill and tap chart. I would return it and purchase a sight that does not require modification to my gun. Below is a link to the thread chart.

http://www.brownells.com/.aspx/lid=11183/guntechdetail/Shotgun_Sight_Bead_Thread_List

[Izzyjoe]

Thanks for the info guys, I didn't know what size tap to use, but I do have 6-48. I'm think about drilling behind the bead and just leave it in place, that way there's just one hole. But once I put it on there, I don't want it coming off, this will be my dedicated turkey blaster!

[dirt road ninja]

http://www.shender4.com/thread_chart.htm

Found this for ya.

[Izzyjoe]

Thanks, that a good drill chart!

[Izzyjoe]

Wow, that front sight was really in there, I clamped a pair of vice grips on it and pulled with all I had, and it didn't budge. With the help of a prybar it come out. Good news is, the hole was already drilled to size for a 6-48 screw, I did have to drill it a little deeper so the tap would not bottom out. It turned out good, but the screws for the rear sight are crappy, I will replace them, and once everything is sighted in, I'll use loctite on the screws!