Grid can not output more than 320 columns?

Can not possible?

The total column width is limited by 32000px. So you can have 1000 columns 30px each.

It is possible to increase this limit -

.aw-grid-view,
.aw-grid-headers,
.aw-grid-footers,
.aw-grid-row {
    width: 100000px;
}

However it may break in older browsers (IE6)

Great! thanks Alex.