The Firing Line Forums - View Single Post - Optic Mounting Problem

Captains1911 · November 30, 2017, 08:45 AM

I've been trying to mount a Sig Romeo 5 red dot to a standard flat top AR-15 upper, and three times now the cross bolt has snapped into two pieces. I know what you're thinking...I'm over torquing the bolt, however, I used a torque wrench set to 20 in-lbs for the first two bolts (per the instruction manual that came with the optic), and the the third time I dialed it back to about 16-18 in-lbs, and had the same result. After the first time it happened, Sig sent me a new base along with a replacement bolt and nut, which I swapped out before the third attempt, so I know it's not an issue with the base. It doesn't feel like I'm putting all that much torque on the bolt, certainly not enough for it to break like it is. I have mounted tons of optics like this with very similar cross bolts and never once had an issue. Any ideas?

November 30, 2017, 08:45 AM	#1
Captains1911 Senior Member Join Date: November 18, 2009 Location: West of the Blue Ridge, VA Posts: 684	Optic Mounting Problem - Cross Bolt Keeps Snapping I've been trying to mount a Sig Romeo 5 red dot to a standard flat top AR-15 upper, and three times now the cross bolt has snapped into two pieces. I know what you're thinking...I'm over torquing the bolt, however, I used a torque wrench set to 20 in-lbs for the first two bolts (per the instruction manual that came with the optic), and the the third time I dialed it back to about 16-18 in-lbs, and had the same result. After the first time it happened, Sig sent me a new base along with a replacement bolt and nut, which I swapped out before the third attempt, so I know it's not an issue with the base. It doesn't feel like I'm putting all that much torque on the bolt, certainly not enough for it to break like it is. I have mounted tons of optics like this with very similar cross bolts and never once had an issue. Any ideas? Last edited by Captains1911; November 30, 2017 at 09:03 AM.