As one who switches between day and night optics often, quick detach or QD mounts have been an excellent tool in my toolbox. They provide great versatility by giving me the option to choose the most appropriate pre-zeroed optic for the task at hand. While QD mounts were always convenient, many people worry about what accuracy they may be sacrificing by not utilizing a fixed mount. Curious myself, I decided to test out how well the Bobro Engineering QD mounts would hold zero when being taken off and then re-attached to the same rail slot.
For my test, I used three different Bobro Engineering QD mounts: two dual levers, and one single lever mount. For each mount, I would fire three 3-round groups, detaching the optic from the top Picatinny rail between each string of fire. Before firing the next 3-round group I would reattach it back to the same rail spot by pushing the mount forward against the Picatinny rail slot before locking this whole scope in place using the QD throw levers.
For all of the testing, I used my savage 110 FCP-SR with a 24” barrel and shot Hornady 308 Win 168 gr BTHP Match rounds. Traditionally I have had good groups with these rounds, so I figured I would use them for this test. After getting a rough zero for each of the three scopes, I started testing groups. I was mainly looking for shifts in accuracy since I knew this rifle and ammunition combo would have good precision. I would fire three rounds no quicker than 15 seconds between each shot and then would walk down to take pictures and mark my groups leaving a few minutes in between each 3-round string of fire.
First up was the Bobro dual lever mount paired with the EOTECH VUDU 5-25. I shot my three groupings from 100 yards and had one flyer on both the second and third groups. Including the fliers, from the first to the second group, the average center shifted left by .21″ (0.21MOA) and up by 0.04″ (0.04 MOA). From the second to the third group the average center moved right 0.44″ (0.44 MOA) and up 0.05″ (0.05 MOA).
The second combo up for testing was the Bobro single lever mount paired with the EOTECH VUDU 1-6. These groups were shot at 50 yards mainly due to the VUDU’s SR3 reticle pattern. The center dot took up most of the center square on the target and shooting from any further away without a crosshair would be difficult for precise groups. From the first to the second group, there was a 0.28″ (0.56 MOA) shift down, and a 0.06″ (0.12 MOA) shift left. From the second to the third group, there was a 0.07″ (0.14 MOA) shift up, and a 0.06″ (0.12 MOA) shift to the left. Nevertheless as seen below, the groupings are very close and have much overlap.
Lastly, I tested the Bobro dual lever mount paired with the Pulsar Thermion 2 XP50. I also shot these three groups at 50 yards. I found this distance the easiest to clearly see the edges of my tinfoil marker to make consistent and precise shots with this thermal scope. From the first to second groups I had a 0.20″ (0.40 MOA) shift up and a 0.02″ (0.04 MOA) shift to the right. From the second to third groups I had a 0.18″ (0.36 MOA) shift down, and a 0.02″ (0.04 MOA) shift to the left. Again, these groups may have had slight shifts, but most rounds were still going through the same nickel-sized hole. Taking into account my shooting error, and the maximum precision of my rifle/ammo combo, there are other factors at play, but overall these results looked very promising.
Something unique to the Bobro QD mounts that I’ve noticed is what they call the “auto-indexing” tab for locating the mount between rail slots. While most other QD mounts have been able to slide quite a bit between each Picitanny slot, the Bobro mounts have very little play. This leads to less possible movement within the rail slot if you aren’t attaching it carefully, and very good repeatability for maintaining your zero.
While the actual locking lever bars aren’t that critical, I have really appreciated the way Bobro Engineering designed them. The locking bar is longer than that of most other QD mounts which gives more leverage for clamping them on (don’t need to torque these mounts down extremely tight, but the longer the lever the easier it is to attach while using the same clamping force). These levers provide plenty of room to get your fingers around for removing the QD mount even while wearing thick gloves.
The QD mount cannot be removed without pressing the safety bar. It is trimmed back to not extend past the body so there isn’t really a snag hazard, and with four springs supporting the safety bar it adds another fail-safe component to the overall system.
Boasting “enough pressure to positively attach any device or optical instrument to a rail without movement, static or dynamic forces notwithstanding,” their locking mechanism has held true. Utilizing some sort of pivoting lever behind two springs, the tab can pivot slightly to apply constant pressure in a linear direction perpendicular to the centerline on the body. This also aids in repeatability and doesn’t allow the user to deform any rail they are attaching the mount to. While previous QD mounts I have used have gouged the rails on my uppers after locking them down, the Bobro mounts have not.
The actual scope rings can detach from the main body of the mount, but are factory set for left or right QD configuration. These aren’t designed to be adjusted by users, and if they are removed and reinstalled incorrectly the indexing tab will not be taking recoil in the orientation it was designed for. Over the course of the last year or so using each of these mounts, I haven’t noticed any major or noticeable change to my zeros, so they seem to hold rock solid.
The main body mount is constructed from 6061-T6 aluminum and the patented BLAC lever system is constructed from 6061-T6 aluminum and 4140 steel. The mount is then finished in hard coat type 3 mil-spec anodized black for a rock hard lasting finish.
After using these three mounts for the last 12 or so months, and removing and attaching them to multiple AR’s I have been very impressed. The shift of zero I have seen has been 0.6 MOA at worst, and negligible at best. For being mounted to my night hunting rifles, this has been more than good enough for me. Most of my shots are within 250 yards and these QD mounts have not failed me yet. As with everything, consumers have to weigh their pros and cons, and while a reputable two-piece mount could hold a better zero, the quick interchangeability with minor POI shifts is something I deem worthwhile.
I have used QD’s for a long time, always with AR type top rails but we are talking 55.6, 300 AAC, 308 bullpup weapons. If I am on a rest so I know it mostly is not me they all land in the 9 or 10 ring and that gets me whatever game I am shooting at. That is the bottom line for me
BoBro QD scope rings are fantastic products, however, that zero repeatability comes at the price of significant weight. Depending on the type and purpose of your rifle, they are perfect…… OR just contribute too much weight to make them worthwhile.