I've been trying to set my intonation after doing an overhaul of my guitar, changing strings, action, pickup height etc, and I've got it all back to good intonation except for the G string. I'm using a Korg CA-30 which I know is not a good tuner for getting an accurate intonation. I've run out of room to lengthen the string and when fretted at the 12th the intonation is off by about 20 cents. Is there any way to fix this without getting a new saddle or something?

2001 Fender MIM Stratocaster
1987 Fender F-210 Acoustic
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The CA-30 is pretty good. Doesn't the Epi LP have a tune-o-matic bridge? You might need to mess with that for a bit until you find something that satisfies all the strings.
I think the LP Standard does have a Tune-O-Matic. There are little screws either in the front or the back, depending on the model. Try adjusting the G string one way or another in small increments, then tune it. See it it makes it better or worse. Then you'll lnow which way to turn it to correct your problem.

p.s. Try moving the G string BACK first, usually this helps.
Sometimes you can flip the saddle around so the bevel is the opposite way to give a little more adjustment. If not a gotoh TOM bridge has a wider intonation adjustment.