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Windage alignment,Weaver base on G2 Contender

Posted: Sun Mar 07, 2010 6:26 am
by Joe O
Anyone have excessive windage misalignment using Burris signature, Z rings ,mounted on a Weaver base, on a G2 contender Barrel?
The scope came off another rifle with Burris standard windage adjustable mounts and turn in signature rings.I've had to install both sets of +/- 10 offset inserts to keep from using too much internal scope adjustment.The base looks to be in alignment.Any ideas?

Re: Windage alignment,Weaver base on G2 Contender

Posted: Mon Mar 08, 2010 5:51 pm
by Lenard
My Burris signature scope had the same problem along with half dozen of the earlier Leupolds. I gravitated toward the Leupold rings and bases because of the limited windage adjustment in a lot of scopes. Believe me, the rear windage adjustable base has saved my bacon a number of times.

In addition, I have seen a lot of receivers that were drilled out of alignment. Pretty hard to take it for granted they will be in line with the barrel.

Re: Windage alignment,Weaver base on G2 Contender

Posted: Tue Mar 09, 2010 1:54 am
by Joe O
Thanks Lenord.I straight edged everything yesterday and couldn't detect a misalignment of the base to barrel,which the base is atttached to.
I shot the scope on another rifle,and it was no problem.I'm pretty sure it isn't the scope,and it has 65 MOA elevation and windage,so no problem to zero,however, it shouldn't need to be moved that far.I agree the windage adjustable bases are great,and I have them on my other three guns.I went with the "Z" rings because of the weaver rail on this barrel.I'm now consentrating on the claw ring attachment.

Re: Windage alignment,Weaver base on G2 Contender

Posted: Sun Mar 21, 2010 8:08 am
by Wrangler John
I decided to use one of my old (Generation 1?) Contender frames with a new 14" SS .223 Rem. barrel in January. Used a Weaver base and Burris Z-Rings that I had, not the Signature Rings with the inserts. Put a Leupold 2.5-5X VariX-III on it, and it hit the 100 yard target about 5" low and 2" right on the first shot. Sighted in with no problems from the mounts and scope.

I have a considerable stock of Gen 1 Contender parts from my IHMSA competition days, so the barrel hinge pin is new. Contenders can be loosey-goosey with frame to barrel fit that causes windage problems.

My problem was that the new barrel wouldn't lock into the frame - the bolt split and hung up on the left side of the frame. New barrels have a redesigned bolt with the unlocking roller bosses cast as one piece left and right. Replacing the new bolt with an original three piece bolt with separate roller pin solved the problem of locking, but made unlocking difficult. Traced the problem down to TC boring the bolt hole in the barrel lug a bit larger, while making the split bolt shaft smaller and "D" shaped, relying on cast ridges to reduce up and down deflection. The bolt deflected to the left due to its shaft diameter being too small. I staked the sides of the bolt shaft hole with a center punch to tighten the fit, and it functioned flawlessly, locking tight and opening easily.

Don't assume it's the mounts or scope, it may be the barrel itself, lug to barrel assembly relationship (it may have been welded on a bit off), barrel pin hole alignment, pin diameter, O.D. of the barrel, or the frame is dimensionally off on one side, or everything all together compounding upon each other. The bore itself may not be axial to the O.D., or there may be a problem with the crown. If your other barrels shoot better with the same set up, I'd bet it is the barrel.

Re: Windage alignment,Weaver base on G2 Contender

Posted: Sun Mar 21, 2010 10:39 am
by Joe O
Thanks John.Just the info one needs when ventuting into a new type action.I'm lucky,in that merely removing the base and turning the Burris Z rings arond,I would up with a set up that was near zero wih the reticle centered.I would have chased the posibility of the base first.The gun only had about 100 rounds through it when I bought it.All is well now and shooting great,Windy yesterday but I did manage a .331 toward the end of my string.I installed a Bullberry barrel hanger and one of their Target semifinished forends,which I shaped and finishd in tru-oil.Worked out real well.Been having problems with the computer the last couple days ,and not able to open my photo program,so no pics yet.