B-Square Bubble Level-Weaver rail

Bought and used in tandem with JIALITTE Bubble Level for 1in / 30mm Tube. Leveled rifle with bubble on each rail, flip 180 to insure accurate. Didn't agree with 2nd rail (Mossberg said I pay for shipping if they address the issue, so decided to pick the rail I believed closest).With gun level, attach in both diections choosing which one allows tightening so bubble moves to center when tight. Careful not to touch it again... now ring bottom halves and tighten using scope pressure to help insure they align. Put JIALTTE. Bubble level on elevation cap, tops almost snug, adjust 3 bubbles and tighten 2nd level.Point at hanging plumb bob to check/ tweak 2nd level. Cross tighten rings watching both levels. Remove both levels, job done.Pull bolt, note boresight and cross hairs not very close (remember the levels on the rails didnt agree). Sad reflection on Mossberg, it may be a scope eater...The levels made short work out of an ugly process, very handy as used.

I purchased this level as a means to aid in the mounting of scopes. Reticle alignment is important, especially on rifles used for long range shooting. I have used various methods to achieve the needed results, with varying amounts of success. I decided to try this level as an attempt to improve on my "set-up" time. I did not intend to leave it installed to use as a shooting aid.I found that the level itself was decently made. MY purchase seemed solid (no loose vial, or obvious mechanical issues..), but I recognize that some other folks here have mentioned some issues with a loose vial, etc. I did NOT have any of those problems.I found the level fairly easy to use. It clamped to the Weaver style bases securely, and stayed there solidly while I was setting up the scopes. No problems. The question of the accuracy of the level should be raised however. I cross-checked mine against a known-good machinist's level and determined that it was SLIGHTLY out of calibration. This seems like it could be prevented in the manufacturing process. The slight discrepancy did not cause me any problem, because I calibrated and re-marked the level appropriately. The knurled nut used for clamping the level to the base seemed a little strange too. Not sure why, maybe just the thread fit.Overall, it's okay, but could certainly be better. I would like the accuracy of the vial to be closer or be readily adjustable and the clamping mechanism to be a closer fit.Three stars. Usable for my purposes.

Well I just go this today, on a balanced rifle (verified) with triple bubble setup this one turned out to be not calibrated. It does make the scope leveling easier for sure, on a weaver rail anyways, I ended up adding a small piece of cardboard on the adjustment side, where the screw is. This is a common issue with anything that makes and adjustment from one side (by a screw) because the screw will pull to one side whatever it might be, rings, bubbles, or any other optic type, you might get lucky and get a proper adjustment, but in my experience I always try to use a better mounting/adjustment system. It is working and it will do what I got it for but it is not calibrated. For the money it could be better, unless you are willing to compromise.

Ok, it's not a top shelf item, but your not paying $50.00+ for a level either. Once attached to the rail, a slight amount of "bending / adjustment" may be needed to calibrate it to an already confirmed leveled rifle. Depending if you are using low rings, there may be a little clearance issue. Using 30mm low weaver tactical rings, you do have clearance without modifiying the level. I've used this level on other rail / ring combinations, and had to file off the top a little to clear. For under $20.00 it's worth adding to level the rifle on the bench. Some have had an issue with the vial coming out, i have not had that problem, but no big deal, glue it back in. Remember, under $20.00. I do like the look and options of where to place the level on the rail, and that i don't have to lft off the stock to confirm level like the scope ring style levels. BTW with the scope mounted levels, unless your scope is perfectly leveled with the rifle, it doesn't matter what you mount on it. The reason for 4 stars is that there is a good chance of stripping out the threads if over torqued, been there done that.

The level fits well on my Mossberg MVP under the scope. Some of the other reviews mentions that the threads stripped when the set screw was tightened. I could feel that the metal was soft when i tightened it down, so I didn't torque the bolt. It fit flush to the weaver mount, unlike others that saids theirs didn't. It did make it very easy to level the scope. Only time will tell if it holds up to shooting.As a note, the bolt that holds it together is not exposed on the mounting surface. This means that the level can be mounted anywhere on your rail system an not just in the groves. I was worried because I only had one groove left on my rail system, however I ended up placing the level on the back 2 cm of the rail, which worked out much better. This should be mentioned in the description somewhere.

This is a simple way to make sure your scope is level when shooting. It is easy to use and if care is taken when mounting is easy to see. Because it mounts on a Weaver type rail be sure you have the room under the scope and correct mounting surface. The one drawback is it sticks out a bit and care needs to be taken on to bump it and break it. There are folding levels available but I have only seen those for mounting around the scope. I have a compact scope and scope ring mount is not an option for me. If you can find a rail mount that folds up it would be preferable. But for the price this one does its job.