I was apprehensive about buying these, but the options were so limited on my Sako .30-06 that I decided to take a chance before looking into far more expensive options. I've had very good results.It's true that there's no way to adjust the alignment when these are mounted to the rifle, but there are ways to compensate for that if you're inventive. For the difference in price between the other scope mounting options, this is absolutely a viable option. If you want to get these things as precisely aligned as possible, follow my instructions below. You'll need a pen & paper, oil, a plastic hammer or other non-marring object for softly striking, a mechanical dial caliper (not a digital), a precision ground 1" diameter round bar, a set of long machinist parallels, or a pair of machinist straight edges, and a machinist vise.Here's what I did...Step 1: Attach the scope rings loosely to the mounting bases and slide them onto the dovetails, temporarily use your scope to roughly determine the distance between the two rings. Tighten the mounting bolts against the dovetails. Once they're seated, use a plastic hammer to tap the bases making sure they're snug enough on the dovetails to prevent any recoil from moving them. Tap them at multiple different points along the front face. This is to make sure they seat to the dovetails as squarely and securely as possible. Then recheck the mounting bolts to make sure they're still properly torqued.Step 2: Take a precise measurement of the distance between the two bases towards the top of the mounting blocks using a mechanical dial caliper. You can place a pair of machinist parallels lengthwise across the two bases; one on each side of the scope rings. Use the parallels as a guide for your caliper jaws to ensure you'll always be touching the same point of the two mounting bases every time you measure. Only put pressure on the jaws of the caliper where it's touching the mounts, and not on the adjustment wheel to avoid any torsion on the needle that would skew the measurement. Record your measurement for later.Note: You can't use a digital caliper for this process because digital calipers use a rounding function to display a value that fits within the lowest resolution of the digital display. During this alignment process, we're more concerned with precise repeatability, and a mechanical dial is far better suited for this...Step 3: Remove the bases from the rifle and install a precision ground round bar into the scope rings. Lightly oil the rings where they touch the bar. Only snug it up enough to remove all the play, but keep it loose enough to slide the rings along the bar with the assistance of a light strike from a non marring object. Lightly snug the attachment screws that affix the scope rings to the mounting bases. Make them just tight enough to prevent any unintended movements, but not fully torqued yet.Step 4: Bring everything over to your machinist vise. Completely remove the bolts and the tabs that clamp the scope mounts against the dovetails and set them aside. Clean the jaws of the vise with some scotchbrite and put a thin layer of oil on the scope mounts where they touch the vise jaws to minimize any scratches. Rest the assembly on a pair of machinist parallels making sure the top of the mounts protrudes above the level of the vise jaws. LIGHTLY bring the vise jaws against the lower mounts. The vise should only be tight enough to restrict the bases from twisting around the alignment bar, but not too tight to where it prevents movement along the length of the alignment bar. Make sure it's located in a position in the vise where you can access the underside of one scope mount. You'll need to be able to tighten the screw that fixes the scope ring to the mount from beneath.Step 5: With the bases lightly held in the vise, Set the distance between the front and rear mounts using the dial caliper and the plastic hammer, and then snug the vise just enough to hold them in place for the next step. This is a critical measurement, so get it as close to exact as possible.Step 6: Measure the distance between the outside edges of each scope ring and the corresponding corner of the mounting base it's connected with. Lightly tap the corner of the scope ring to twist it on the base until the distance is equal on both sides. Clean all of the oil off of the plastic scope ring inserts and the alignment bar, and then reinstall and finish torque the scope rings onto the alignment bar.Step 7: Tighten one of the scope rings to the mount and recheck your measurements making adjustments as needed. You may need to "predict" the scope ring twisting when it's torqued to where it's properly aligned after it's fully torqued.Step 8: Turn the whole assembly around in the vise and repeat step 7 on the other scope mount.Step 9: Measure the distance between the front and the rear scope rings on both sides to verify accuracy.Step 10: Move everything back over to the rifle and install everything. Finish torque the mounts to the dovetails, remove the alignment bar, and install your scope.