Re: How to adjust action of RG321
Not an expert but I'll give it a shot...
First, make sure your neck doesn't need any bow correction. To do so, measure clearance at 9th fret while fretting the 1st and around 17th frets. It should be more or less as a biz card clear on the E's being closer to the fret crown on the High E.
Then, measure the free space between the 12th and 24th (or 22nd, whatever your guitar is last fret) and make sure it's within specs. You'll have to dig those up.
Measure also clearance from bottom of string to fret crown at the nut. Make sure it's within specs.
Now, if your nut height and neck bow are correct, but you still have higher action than wanted you can lower the bridge saddles.
You have two routes.... the simplistic one, not so good. And the proper one.
The simplistic one is the one I took to adjust my GRX20. I just lowered the saddle by unscreweing the saddle adjustment bolts (1.5mm allen wrench) in the same measure for all bolts, so the radius would not be much affected.
After every change, retune, wait for the neck to settle and remeasure everything.
The proper method is to cut a template with the desired radius on thick cardboard and lower the saddles while measuring the radius, so you get it perfect.
If you can't get the saddles low enough, refer to the homepage here on jemsite and look into neck shimming. You may need to shim the neck to get even lower action.