Couple of things;
1) Ammo is not as expensive OR hard to find as most people imply. I have no problem finding ammo for mine and it s only about 10% more expensive than 45ACP.
2) Double Tap ammo is awesome. I typically carry their 135 grain load in summer with a magazine of 165 grain Gold Dots as backup. For hunting I carry the DT 200 grain HP loads.
3) You can buy various different caliber barrels for your G20 as well. You can get a 40 S&W barrel, a 357 SIG barrel, and a 9x25 Dillon barrel, all while using your stock magazines and other parts.
Enjoy your new weapon, it's a good one.
