Left windage Problem

[lfudickar]

I have a DPMS AR 10 upper that i just mounted a Nightforce 2.5-10 vxs on with LT104 Rings . At 25 yrds i could not get enough left windage out of the scope. it consistently shot 4 inches right. I remounted the scope with Nightforce rings and again it shoots 4 inches right with my left windage maxed out. Any ideas would be appreciated.
Thanks

 

[blksno]

Turn your rings around backwards and see if it switches. If it doesn't, then your rail may be out of spec.
Pull the scope/rings off and put them on another rifle and make sure it's not an optic issue, you have all the windage you should.

 

[SaskShooter]

Do what c_bass16 said. If you find that your rings and scope aren't the problem, and it is your rail, you could either get rid of the rifle or try a pair of windage adjustable rings.

 

[msalm]

Or it could be the factory barrel extension/thread tenon is WAY out of wack and it just needs a precision barrel installed properly... Just a guess though. I've built quite a few AR's and the barrel extensions can have a goodly amount of runout w/ one manufacturers exception and that would be the extensions manufactured by BAT machine...they are never out more than .001" and usually half that. Factory extensions are typically over .010".