[Jeff M]

Just to add to what LJ said,
Barre chords have nothing to do with strength. It really is all about techinque.
Some little kids can do barre chords, while some large, muscled men can not.

Some tips;
Let your fingers, hand, wrist, arm relax rather than tighten. Let the weight of your arm travel down to your elbow and towards the floor, while resting your barre finger against the fretboard to prevent it from falling off. Let your shoulders relax down and back ....this will help pull your hand into the fretboard.

Rotate your hand/barre finger a bit backwards, so you aren't trying to press the strings down with the flat part of the finger. ALong the same lines, see if you contacting some of the problem strings at one of your finger joints, which will hinder fretting that string.

See if you actually need to fret each of the strings to sound the chord or if you can "cheat" and just fret a few solidly with the barre finger while your other fingers fret thier strings.

When moving into a barre chord, place your non-barre fingers down first, then the barre. When you get up to speed, they are basically fretting at the same time..but it will feel much smoother and you will be fretting the strings more solidly.


Bottom line is to concentrate on relaxing your muscles to play the chord, not tightening them into a death grip. This actually can lift your barre finger off the string....and make things worse.
The natural reaction is to tighten your muscles the more frustrated you get. Make it into a gentle game. How lightly can you fret a string and still make it sound cleanly?