[big shrek]

I put my old Tasco on an old Marlin 30-30 with a Weaver Base, but it shot 7" to the left at full adjustment. I turned the rear scope mount around and it shoots 4" to the left now at full adjustment.

Should I now switch the front scope mount around as well??

Or did I goof on putting the Weaver Base on properly?

Should I remove the base & re-set the set-screws??

[EviL]

maybe your rings are not aligned and making your scope a little cockeyed. if thats the case, hopefully the tube hasnt been crimped.

[oldjarhead]

Are your rings high-mount, low-mount, medium?
High mount rings may have been bent somehow but it would take a lot to bend them. I would suggest trying a different set of rings if you have extras. It's pretty hard to mismount a weaver base. Is the base correct for the rifle; sounds silly but most are not interchangeable.
Are your bullets straight?
(that's a joke)

[roverboy]

Yeah try some different rings.
Its worth a try. Good Luck

[big shrek]

Looks like the culprit is the base itself...it's off a couple of degrees when I put a level to it (finally FOUND my level...).

It may very well not be the proper base, i'll take it in to the shop this weekend and find out.

[SwedeSteve]

Trya different make base.

[GlockMeister]

Gotta get yourself one of these. Then anytime you mount a scope pr replace a scope. you'll be sure it's on right.

Wheeler Professional Scope Mounting Kits From $89.99, SCOPE SHIPS FREE on orders $29.95 & up

And FWIW, it can be found on sale for like $69.99. That's what I found it for at MidwayUSA.