Your leupold mounts are sturdy enough,

[tjRoberts]

But for shooting at 1000 yards ,
You might not be able to get enough elevation from your scope itself.
I would certainly try with what you have now , cause it might be fine.
You probably should talk to a tech at leupold , they would be the experts on the subject. and are as good at customer service as it gets.
A 30mm tube will give you more elevation though. Have a look at the leupold europian scopes...tj3006

 

[JD338]

For long range shooting, you can get 20 MOA bases and rings.
30mm tubes will give you more internal adjustment.

JD338

 

[FOTIS]

For long range shooting, you can get 20 MOA bases and rings.
30mm tubes will give you more internal adjustment.

JD338

YUP!

 

[Guest]

You can also gain 40MOA back by using the .020" offset inserts in Burris Signature Rings, which will work on standard Leupold bases. I've had great service out of them on one rifle, and will put them on my next rifle as well.