Marwan,
I started using Beuchat with caps and now use Beuchat & Imersion with sphere nuts inserted into the rubber end + constrictor, i.e. without the caps.
=>
http://www.chasse-sous-marine.net/ca...oducts_id=1253
Be aware the new Beuchat caps are
extremely thin 
and the tahiti wishbone puts a lot of strain on the caps via the metal washer. You can notice the plastic material giving in by small white streak at the end of cap where the wishbone arms are inserted.
If you care for your fingers, I suggest you either replace the caps or do as I described above (the ease of loading long arbaletes even increases and you stretch the rubber a bit more with this set-up without any risk of the caps exploding).
Cheers,
ulysses
P.S. No hard feelings about the Gara vs. Ice discussion
