Rifle Scopes Trouble with a 20 MOA base and Leupold MK4 3-10x40

[Hookman]

I mounted a Leupold M4 3-10x40 M3 on my FN SPR that has a 20 MOA base installed on it and am I having trouble getting a zero at 100 yards. There doesn't seem to be enough elevation adjustment, I cranked the turret as far down as she will go and I am still about 4 inches above my POA. Has anyone had a similar experience with the Leupold?

 

[ORD]

Re: Trouble with a 20 MOA base and Leupold MK4 3-10x40

The Leupold should have 65MOA of adjustment, so a setup with any 20MOA base should work without any problem to get you zeroed at 100yds. I have had a Mk4 M3 mounted with a 20MOA Badger on a 700 in .308 and I got a 100yd zero with plenty of adjustment to spare.

It sounds like a scope problem and not a base problem, unless you somehow got a 40MOA base that was mislabeled as a 20MOA.

 

[Alpine 338]

Re: Trouble with a 20 MOA base and Leupold MK4 3-10x40

Try dialing the scope from stop to stop on the elevation to see if you get the 65-moa. Then take it to center or 32-moa or so from one end, then add 20-moa (impact up) and then do a bore sight i.e. look at your 100-yard target through the bore, and then see where the reticle shows up on the target. You should be close, at least on paper.

 

[MontanaMarine]

Re: Trouble with a 20 MOA base and Leupold MK4 3-10x40

The M3 has stops that will prevent the knob from rotating fully up or down with the indexed cover in place.

You need to remove the cover, then zero with the cover off (use a coin or something to turn the erector), then put the cover back on with the zero indexed.

 

[Hookman]

Re: Trouble with a 20 MOA base and Leupold MK4 3-10x40

Thanks for the advice guys. I will double check to make sure it's a 20 MOA base, count 65 MOA end to end and get it centered within the adjustment range. I am pretty sure it was zero-ed with the turret cover removed but I will try to re-zero it at the range this Friday.

I will keep you guys posted on my results.