I've never seen or heard of anyone using one besides Dick.
The problem is no 2 shells are exactly the same. If one shell is 1200 fps, @ 10,000 psi (just for round numbers), and the next shell is 1190 fps and 9,500 psi, bolt speed and the ejection force of the hull will be slightly different. This is evidenced by the fact that for every shot you take, the hull doesn't fall in EXACTLY the same place every time.
It seems like with the multi-catch, so many things have to go right and be absolutely perfect every time, when its pretty much guaranteed that that is impossible.