First range trip

[Hoot]

Even though I McGyvered the scope mount, I'd rather do a more perminent fix. A buddy on afrcom is going to borrow me his lapping tool and abrasive compound. I'll let you know if it works.

Keep in mind that a ring lapping setup is for making the rings surfaces true to one another. It is not for imparting an intentional offset. I suppose you could use a lap and bear down in the direction you want the fit to drift, but it would be an imprecise process and take an hour or two with the grit they use for lapping. It also would in all likelihood ruin the lapping rod for future truing.

Hoot

[mnhornet]

Guess I'm going on the assumption there is a high spot at 12:00 since it is shootong low. I don't plan to bias anything. I either true it up, or stick with the McGyver fix.

[Hoot]

Guess I'm going on the assumption there is a high spot at 12:00 since it is shootong low. I don't plan to bias anything. I either true it up, or stick with the McGyver fix.

The bottom halves of the rings should be the only part that contributes to high or low. The top halves just serve to retain the tube to the bottom halves. It certainly won't hurt to lap them though. Go slow and observe. It's your strongest tool. If you see one ring loosing a lot more material than the other on the bottom, chances are it is the one which is too high. If they loose equally, then you have to consider the mount to the receiver rail is where the offset is occurring and all the ring lapping in the world wont fix that problem. I assumed you tried reversing the mount to see if it shot high then? Give the bottom of the PEPR a good look for burrs or excess coating. Ditto on the receiver rail. Try moving the PEPR further forward or back and see if the problem follows it. That would exonerate the receiver rail if it shoots low regardless of position along the rail. Then, your' back to either an untrue receiver face or actually a manufacturing error on the ring part of the PEPR. In the latter case, lapping may just be the ticket. Also, make sure the indexing notch on the receiver for the barrel is deep enough and that the indexing spur on the barrel is not bottoming out in that notch as that would impart a slight downward tilt on the barrel. I'm just throwing out what is possible. For what the Burris PEPR mount costs, I'd expect the tolerances to be very good. Receivers on the other hand can have burrs on the picatinny rail, that's why I advise a close inspection.

I've used a half round .005 brass sheet shim to pull a scope in and in a pinch, a cut of aluminum pop can has saved a lot of folk's range outing. There's no disgrace nor long term reliability issue with using a shim, if it's properly done. Some rings come with adhesive backed paper shims you can put in them to protect the scope from marring. If they're reliable, a metal shim should be even more so.

Keep us in the loop on what you find.

Hoot

[mnhornet]

Hoot, Thanks for adding more info on things to check. I should probably look into the mount a bit more, before I go willy nilly into messing with an otherwise perfectly functioning rifle. It would be prudent to at least make sure the rail mount and rings are on the same plane.