From African Hunter Magazine:
Most rifles work perfectly on range when zeroing a rifle or shooting off sticks in an accuracy test. A surprisingly large number fall apart as soon as the pressure is on and you have to shoot and reload in a hurry.
...
Then we come to one that surprises me. Ruger. The early Ruger M77's with the non rotating claw extractors but still a push feed mechanism, in .458 Win could be relied upon to jam if the bolt was worked quickly. In the 1980's the National Parks culling teams found this out the hard way and the new Rugers were quickly disposed of or issued to stations where a heavy rifle was seldom required. The new MkII Ruger with a proper controlled feed seemed to be a vast improvement and were reputed to work a whole lot better and of course come at a top dollar price.
I learned differently. All but one out of seven I’ve seen or handled this year (6 in .416 Rigby and one .458 Win)
would not eject if the bolt was opened vigorously. Slow down just a fraction and they throw the empty case half way into the next province. For a client coming out to Africa this may be acceptable. Any really fast fancy shooting is going to be the PH’s.
For the Professional Hunter or Guide though, a rifle that is guaranteed not to eject when worked at speed is
a death sentence waiting to happen. The fault lies with the sprung loaded ejector that springs into place as the bolt is withdrawn. Work the bolt at a moderate speed and the ejector is in place to cleanly throw the case clear. Work the bolt fast and the ejector is still on its way up when the case passes over it. A few will work provided the ejector is scrupulously clean and well oiled but many will not do even that (and how do you keep it clean AND oiled in the usual dusty conditions?). A much stronger spring and a little polishing of the raceway that it fits into may cure the problem, but they are not safe as they come from the factory. A local gun shop tells me that they have sent two new rifles back this year because of this problem, and our local top gunsmith tells me that
while most can be made to work perfectly, some cannot. Ruger needs to wake up, their No.1, single shot rifle is a far safer and more dependable weapon than their bolt action.
http://www.african-hunter.com/lessons_learned.htm