Scop base problem

I have a savage model 12 low profile varmiter action. I put a new weaver 20 minute one piece base on it and everything matched up perfectly. After I put it on and tightened it up we dropped a strait edge across the base and it had a bow in it. To me this shouldn't make any sense because when I dropped the strait edge across the bare action everything is perfectly strait.

When laying the strait edge on the front of the base at the front of the receiver their is roughly a 1/16th inch gap at the rear of the base indicating to me that the base is torqued in the middle causing the gap at the rear of the base. If the process is reversed then it shows up as a 1/16th gap at the front of the base. The total length of the base is 7 inches.

I am not an inexperienced shooter but this doesn't make any sense to me. I have never had a situation like this before. Does anyone out there know or have any bright ideas on what the problem is or how to fix it short of buying another base and still possibly having the same problem.

It would seem the screw holes aren’t drilled perfectly. Too close together, or the rail itself being too far apart, causing the rail to arch slightly. (Rail is higher in the middle than at the ends.)

I would check the base when it is not on the rifle first. If it is straight (top and bottom) when not mounted then it is probably what Dave refers to.

I am not sure I would blame Weaver as the fault may be with how Savage drilled the holes.

Remove the base. Take that straight edge, lay it across the top of the action to see if it makes contact all the way down. If it doesn't, Ruh Roh. Someone removed a barrel incorrectly.

Savage actions having scope mounting problems or screw holes drilled wrong??? Say it isn't so!!
As mentioned, check the action. If it comes down to an action problem, (???) might considerer a press to correct the "mount" fit.
I went as far as to have a custom mount built from pieces (new, cut and re welded) to get the fit I was wanting. :cool::cool:

Something you can check, remove the screws then install only the 2 front screws and tighten them down. Does the rear portion of the rail sit raised above the Receiver? Next, switch the screws to the rear only & tighten. Does the front of the rail sit raised above the surface, or normal? Do any of the screws seem strange when tightening? Do any feel like they are going in at an angle?

If all else fails, you can use a 2-piece base.

Any updates? Been a couple days.

I happen to have a spare weaver 20moa base here like the one you have and just laid a straight edge on it and it’s perfectly flat, and didn’t notice any gaps when I had it on my action.
Hopefully yours is just a defect in the base and not a warped or twisted action.

When you tighten the one end of the base down and have the gap at the other end, is the gap pretty much even across the rear of the base? Or is there a larger gap on one side than the other? That might tell you if the front of the action is twisted(most likely from improper barrel removal previously).

If it does turn out to be an action issue, the easiest and cheapest fix might just be to bed the scope base. Just use release agent on the action side so it can be removed if needed.