Hey guys, just finished up what became a long, nightmare process using Burris' 34mm Signature rings to mount my Burris XTRII 5-25. The reason for this post is so that hopefully, nobody else has to go through what I have.
I'll start by saying that this is in no way intended to knock Burris or their products. Their tech support has gotten to know me on a first name basis and they have been nothing but outstanding and have bent over backwards to help me in this process.
This all started when I bought my new XTRII. I decided to mount her up with the Burris Signature rings. I ALWAYS use a torque wrench when mounting bases and optics. So, my first call was to Burris tech support to get their torque specifications on the ring top screws with which they told me 20-25 in./lbs. I felt like 25 in./lbs. was a little high so I used 20. Right away it was obvious that I could not get the rifle to zero. It appeared to be double printing and groups were 1.5MOA plus...keep in mind this rifle normally shoots .2-.3 MOA.
I put in a call to tech support and we set up an RMA to send the scope in. The scope was tested under Burris' normal tests when they receive a scope. It was determined to have no issues and I got the standard message of..."you have maxed out your adjustment...do this, this and this to correct."
So, I mounted the scope back up to the rifle just like the first time at 20 in./lbs. Took it out to zero...same thing. Big, ugly grouping and not able to zero. I pulled the scope back off and mounted up my trusty Burris Veracity 3-15 with Vortex precision rings to help in the troubleshooting process. I had the rifle zeroed in 4 shots and it was back to grouping in the .3's.
Called tech support again and set up an RMA to send the XTRII in a second time. As before, they proceeded with their testing and found nothing wrong with the scope. Again I got the message that I was nearly maxed out on my internal elevation adjustment. Who cares? That's what these were made for right?
Got the scope back and mounted up to 20 in./lbs. This time I noticed my parallax knob was acting funny. I hadn't noticed before because I was only shooting at my zero distance...200 yards and really didn't need any parallax adjustment changes. With the scope mounted to 20 in./lbs. I now noticed that the parallax knob felt inconsistent and was certainly getting in a bind. Now we're finally getting somewhere! Realizing what was going on I backed off my far ring torque setting to 15 in./lbs. I determined this to be the absolute max torque that I could put on the ring caps and not put a bind on my parallax mechanism.
I took the rifle out and it zeroed quickly. Groups shrunk back down to what they should be. However, I noticed in the process of shooting that at 15 in./lbs. the screws were slowly backing off. One day I shot 15-20 rounds and the screws loosened significantly. This happened 3-4 times and every time I finished shooting I'd check ring torque to find that the screws had loosened up.
I called tech support again and made them aware of my findings and also that the lower torque setting was clearly not a long term solution. They agreed to send me a new set of 34mm Signature rings to troubleshoot with. I found the exact same thing...that any top ring screw torque over 15 in./lbs would begin putting a bind on my parallax mechanism. Once confirming this, Burris tech support agreed that there still had to be something wrong with the XTRII. So, back in again it goes for the 3rd time.
I think by this point the people at Burris were a little nervous that I was about to blow. I wasn't, I just wanted a permanent solution and to get back to shooting. About 4 days later I get a call from the repair shop where I was told that my scope tube was in fact slightly football shaped where the far ring was clamping. WTH!!! I asked how this could have happened when I was using all of Burris' products and their torque specs. I didn't receive any comforting direction other than to try again with the new XTRII they were sending.
Got the new scope back and mounted it up with the newer set of Signature rings that Burris had sent me. This time I filmed myself in the mounting process because I knew that I would still have the same issue. Sure enough, slowly brought the torque up to 15 in./lbs. I could tell on this new scope that this was still the max torque it would put up with and not affect the parallax mechanism. In the video I went to 17.5 in./lbs just to prove that it was over and was certainly putting a bind on the parallax. Trying to rule every potential issue out, I contacted a friend who had a nice, $180 Mac Tools inch pound torque wrench. We ran my Wheeler Fat Wrench directly up against his Mac and we were +/- 2 inch pounds at all ranges. At the 20 in./lb range we were identical.
I contacted the service department as well as sent them my video of the process. After watching my video the tech in the service department felt I was incorrectly torquing the scope. In his words I was "over-torquing" the rings even though my Fatwrench was only set to 15 in./lbs. He also admitted that there was a "compress-ability" to these ring inserts which would explain the squishiness when trying to achieve a correct and final torque.
I worked in the heavy truck industry for 17 years and in that time torqued a lot of critical components. Many of these torque sequences were on cylinder heads where you're compressing a head gasket. Anybody who's ever torqued a component down with a thick gasket knows that you have to torque the bolts several times to achieve proper fastener torque and take the "squish" out of the gasket. When you torque one fastener, the ones next to it lose torque or clamp load. This is a well known fact and is in the service manuals. Some manufacturers even recommend the cylinder head be torqued again after a certain time of usage.
So where was I going with that analogy? To tell you how I mount scope rings. Once I get the scope leveled and rings screws are just past snug, I begin to slowly bring them up to a low torque setting while crisscrossing side to side. I set the torque wrench to it's final setting and continue to crisscross until all fasteners quit moving. This happens quickly with solid rings. With the Signatures I discovered (as confirmed by the service tech) that the inserts are very compressible. This requires crisscrossing many times until each fastener quits moving.
I did specifically ask the Burris service tech what his personal method was when torquing down the signatures. I won't go into his whole answer now but will say that he is NOT achieving a correct or consistent top ring fastener torque. Some of his fasteners will have more torque than others. His overall torque (even though his wrench is set to 20 in./lbs.) will be achieving less clamp load than my procedure at 15 in./lbs. Keep in mind, at 15 in./lbs my screws kept coming loose.
At this point I knew that I needed to get completely away from the Signature rings. Burris tech support was kind enough to send me a set of their solid XTR tactical rings with the 3x3 screw design. I returned the 2nd set of Signatures they sent me. As I knew it would, the scope mounted up beautifully achieving a quick final torque of 20 in./lbs with no issues at all with the parallax binding. Problem solved!
Final thoughts:
In my opinion there is an engineering issue with the Signature rings at least in the 34mm tube size. With the plastic inserts there just isn't enough solid support to the scope tube. Again, they are very compressible, not what I want in a scope mounting system. It could be that if the inserts were of an aluminum alloy they may work great. I do like the concept of cant in the rings and the idea behind it. I'll note that I have a couple friends who swear by these rings in 1" and 30mm sizes who have not had any issues. They also don't believe in torque wrenches so undoubtedly scope tubes are being over-torqued and excessive clamp load applied. It may be that there's enough support to the scope tube in these smaller tube sizes for the system to work.
In summary, my problem is solved. Burris has been awesome and has worked hard to try and keep me happy and provide solutions. If you are considering these rings in 34mm, just beware.
