If you plan on feeding the rounds out of a magazine, then the OAL gauge is largely useless. Mag length is a lot shorter than an optimum length, as you've discovered.
I seat my standard loads to 2.260 to 2.265 and they feed perfectly out of Colt 20 round mags and any Pmag. I can only recall one fail to feed in the past year and that was with a brand new upper. I would be real surprised if a 2.265 round would not work in your RRA.
If you are thinking of loading accuracy rounds, then the OAL gauge is a critical step. In this case you'll be loading rounds that are too long to fit in a magazine and you'll be single loading (more than likely).
I load 75g Amax's to .015 off the lands and those rounds are insanely long.
Keep in mind that when using the OAL gauge, you're measuring to where the bullet touches the lands, and that has nothing to do with the tip of the bullet. So you should use a bullet comparator gauge to measure the length of your bullet from the ogive area of the bullet and not from the tip, simply because the tip of any given bullet can vary considerably.
I think a step that is more important, and widely ignored, is using a case length gauge to figure out exactly how much to resize your brass. If you use the standard published specs or if you set up your sizing die according to the instructions - you're probably resizing the brass way too much.
By using a case length gauge you can set your sizing die to resize a minimum amount. Over sizing is basically allowing the case to flop around in the chamber. Whereas a properly sized case is going to fit nice and cozy in the chamber and will likely give you an accuracy boost.
This is similar to a bolt gun user only neck sizing brass so that the case fits that particular chamber nearly perfectly. For us AR shooters, we have to full length size, but we don't have to adhere to SAAMI specs, which is just a "best fit" sizing that will work in pretty much ANY rifle. SAAMI specs, in my opinion, are great for commercial ammo, but has nothing to do with how I load rounds for my specific rifle.
Here's some links.
Case length gauge/headspace
http://www.sinclairintl.com/product/8809/Case-Gauges-Headspace-Tools
bullet comparator
http://www.midwayusa.com/viewProduct/?productNumber=231904
Great single load mag
http://www.creedmoorsports.com/store/product.php?productid=16316&cat=283&page=1