Still would be considered as over priming by many though.
Warra posted a really good little tutorial on adapting those priming measures for non-standard bottle sizes on another board once. Perhaps he might be persuaded to repeat it here?
OK, here it is:
I have always bottled all my brews, and envisage I'll continue to do so into the future.
Fortunately, I've not had a bottle bomb since 1973. I do leave all my brews in the fermenter for at least 2 weeks, except Hefeweizens, which I bottle after 7 or 8 days. However, Hefeweizens don't last long, I start drinking them 1 week post bottling, and a batch is generally gone in 4 to 6 weeks.
My preferred priming medium is Caster Sugar, and I use the priming measures available from HB shops, BigW etc to dispense the sugar through a small funnel into my bottles.
My experience is that the standard measure delivers priming at the very high end of the range, at about 2.9 volumes.
That's fine if I bottle say, a Hefeweizen, but it is totally unsuited to my preferred carbonation level for Pale Ales, Bitters etc etc.
Additionally, the measures are designed to dispense priming medium for 750 mil and 375 mil bottles. That makes it difficult to dispense an accurate measure in 500 mil bottles.
This is how I dealt with this issue. The photo shows 3 dispensers.
One is the standard one as bought from the HB shop. It is what I use for 375 and 750 mil when bottling hefeweizens.
Another one has been cut down with my modeling knife, commensurate with 500 mil bottles. I used a set of calipers to get precise measurements when doing this.