Mike,
What's the Magnum weigh? I know that a Saito .72 is only slightly heavier than an OS or TT .46.........
If the Magnum really is that heavy, you might need to worry about the weight.....I don't have the Giles, but I have the Phoenix Sukhoi SU-31, and I had to move the radio gear and battery to the rear of the radio compartment to balance it with a TT Pro .46 up front....