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Posted: 9/10/2011 1:28:50 AM EDT
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The absurdity of this question will probably draw some criticism but I will ask anyway. After a brief discussion with a co-worker regarding mounting accessories to a picatinny rail the subject of how tight those accessories should mounted came up. I hadnt put much thought into the question since I typically mount it "tight enough" - or so I thought. Looking back I have probably been gorilla gripping most of the stuff I mount (I actually cracked a CAA stubby vertical grip through, from what I can tell, over-tightening it a couple years ago). I typically mount optics hand tight and then tighten them down with my trusty spyderco until the nut refuses to turn anymore. Is there a good rule to follow when mounting accessories on a rail? I have yet to damage a rail but the thought of screwing up a flat top upper is not appealing. Any advice, reccommendations, or rules of thumb will be appreciated.
DAW |
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Quoted: The absurdity of this question will probably draw some criticism but I will ask anyway. After a brief discussion with a co-worker regarding mounting accessories to a picatinny rail the subject of how tight those accessories should mounted came up. I hadnt put much thought into the question since I typically mount it "tight enough" - or so I thought. Looking back I have probably been gorilla gripping most of the stuff I mount (I actually cracked a CAA stubby vertical grip through, from what I can tell, over-tightening it a couple years ago). I typically mount optics hand tight and then tighten them down with my trusty spyderco until the nut refuses to turn anymore. Is there a good rule to follow when mounting accessories on a rail? I have yet to damage a rail but the thought of screwing up a flat top upper is not appealing. Any advice, reccommendations, or rules of thumb will be appreciated. DAW I used Blue loctite and tighten until snug. Hasn't been an issue yet. |
I believe there is an 'ideal' amount of torque that is applied. Obviously there is a point where it is too loose or too tight. To my understanding the amount of torque applied is more for returning to zero, but I do not recall what the ideal torque setting is. I use LaRue mounts so that makes it easy to forget 
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Quoted:
#8-24 and 8-32 screws 25 in.lb. #10-24 and 10-32 screws 40 in.lb. #12 - 1/4" (mounts with nuts) 65 in.lb. Torque values should be reduced with polymer mounts This is great info. Now, if you had access to a torque wrench, you could quickly teach yourself what 25, 40 and 65 in-lb feels like when using your ratchet. After you learn, you don't really need the torque wrench any more, unless the installation is somehow critical. Most things are not critical, you just need to get close, especially if you are using a thread locker or self-locking nuts. |
| I usually tighten until its solid hand tight then try and wrench it another 1/4 turn. Also I now ALWAYS use blue locktight. I tightened a Troy BUIS as hard as I could "hernia" tighten it with a screw driver, I thought. Once at the range, after about 200 rounds, I got up to leave and the Troy BUIS just fell off the rail. |
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Forgotten where I copied from:
Scope Mount Torque Specs Several of the regulars, me included, frequently get questions on torque specifications for bases and rings. The purpose of this thread is to have one central location that lists as many brand- and model-specific torque specs as possible. This will be something of a "self-policed" thread, so please provide a link to the source when listing the base and/or ring and their manufacturer-recommended torque specification. All torques are in "in/lbs" and that is NOT THE SAME as ft/lbs! And to begin: Badger Ordinance http://www.badgerordnance.com/folders/downloads/3/Mounting%20rings%20and%20bases.pdf rail to receiver: 15in/lbs rings to rail: 65in/lbs upper ring half to lower ring half: 15in/lbs Seekins http://www.seekinsprecision.com/index_p.php?p=rails rail to receiver: 15in/lbs http://www.seekinsprecision.com/index_p.php?p=rings rings to rail (clamp screws): 55in/lbs top ring half to bottom ring half: 15in/lbs Talley light-weight allow scope mounts (specs not listen online, I called, he said it was OK to post these, call to verify if you wish) base to receiver:20-25in/lbs ring halves:15-20in/lbs Warne (please verify this! I called and was told all screws and bolts are 25in/lbs) ring halves: 25in/lbs rings to rail: 25in/lbs SWFA SSALT http://www.opticstalk.com/forum_posts.asp?TID=18199&PN=2 (As per Chris Farris II's post, second page, first post) base to rail: 40in/lbs ring halves: 18 in/lbs LaRue Tactical LT-104 QD SPR mount ring halves: 35in-pounds. (Verified with a call to Tech Serv, asked them to be sure, talked with 2 people, 35 in-pounds.) |
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