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-   -   Riser Height? (http://www.firearmstalk.com/forums/f20/riser-height-89187/)

pawjr74 04-20-2013 03:31 AM

Riser Height?
 
What do you think would be the lowest riser that would either co witness the A2 front sight or clear it? Would a 1/2 inch riser be high enough? I'm running a cheappy non magnified red dot 40mm. I don't like the riser I'm currently running as the MBUS won't fit on the rail with it on there. I'd like to go a little lower if I can. This riser easily clears the front sight. (I can still see the front sight through the red dot with this current set up)
http://i64.photobucket.com/albums/h1...ps2036aacb.jpg

highpowerguy 04-20-2013 02:06 PM

The a-2 sight height is 2.25 if I am not mistaken measure from the center of your optic to where it meets the top of your picitany rail and then subtract that from 2.25 and that will give you the height of the riser you need.

pawjr74 04-20-2013 11:14 PM

Thanks for the info. I'll check it out.

highpowerguy 04-20-2013 11:43 PM

Actually I am a little off on that. The sight height is 2.25 inches from the bore line not the top of the rail, you also have to subtract the height to the top of the rail which is about 1.2 inches. So you actually need to subtract the height if you optic from 1.05 inches to get a perfect co-witness however one inch will work fine. Sorry about that I wasn't thinking it all the way through probably shouldn't make forum posts before noon.

pawjr74 04-21-2013 09:34 PM

Went with a 1/2 inch riser and it's now co-witnessed. Thanks for the help. I know it's a cheap WM red dot...next rifle I'm going to build and it will be upgraded :)
http://i64.photobucket.com/albums/h1...ps4ca530ac.jpghttp://i64.photobucket.com/albums/h1...ps8dcc65ae.jpg
http://i64.photobucket.com/albums/h1...ps0e242cc3.jpg

Quentin 04-22-2013 02:15 PM

That first riser was about 4" long! No wonder there wasn't rail left for the MBUS!

pawjr74 04-22-2013 08:08 PM

Quote:

Originally Posted by Quentin (Post 1223060)
That first riser was about 4" long! No wonder there wasn't rail left for the MBUS!

Ya, I figured that out about 5 seconds after installing it! LOL

Quentin 04-22-2013 11:39 PM

Quote:

Originally Posted by pawjr74 (Post 1223408)
Ya, I figured that out about 5 seconds after installing it! LOL

Yeah, not making fun of you... I've got one of those things stuffed in a drawer somewhere, too! :D


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