Whenever there is more than one option, shooters around the world will have vastly differing opinions for and against each. The same could be said for push vs controlled feed bolt action rifles. However, after over a hundred years of having both on the scene, it seems a sort of stalemate has been reached.
People still have their preferences, but realistically, there are much more important factors to consider when choosing a bolt action rifle, and the feed/eject mechanism is almost ancillary to other concerns. That being said, there are differences.
The double feed
A push feed action is exactly what it sounds like. The round is pushed by the base of the bolt into the chamber. Once the bolt is fully closed the extractor claw will engage the rim of the cartridge, so that the ejector plunger can push it out when it’s clear of the chamber again (once the bolt is pulled rearwards).
The oft-quoted push action double feed can occur if you do not fully close the bolt upon chambering a round. This means the round will not eject as the extractor claw has not engaged the cartridge. If you move the bolt forward again, you’ll feed a second round into the base of the first.
This situation is very unlikely to occur, except through clear operator error. We all like to think we’re beyond such simple mistakes, but stress can cause us to do funny things. When might you be this stressed? Hunting dangerous game, or perhaps in fast-paced action matches like the Precision Rifle Series. However, most competitors use modern push feed actions without any issues. Big game hunters on the other hand, are probably the biggest proponents of the Mauser-style controlled-round feed.
Making life easier
The main reason for the proliferation of push feed rifles is that they are cheaper and easier to manufacture. Having said that, some very expensive, reliable and accurate rifles use push feed actions.
There’s one thing that just makes like easier with a controlled-round feed. You don’t have to push the bolt fully closed, or completely work the action, to pick up and eject a round. And no, this isn’t the same point above worded in a different way.
If you spend a lot of time on the range drilling small holes into paper, you’ll come across plenty of situations where you have to clear your rifle so someone can go forward. This may be for a change of targets, a ceasefire in a match or some other situation where rifles need to be made safe.
If you have a box magazine, no issues either way. However, if you have a blind magazine, emptying a full mag with a push feed action can be annoying and time consuming. A good example of this is the Mossberg 100 ATR which I recently reviewed. A nice, slick bolt action, but you can’t pull the magazine out or drop a floorplate if you want to quickly empty your rifle.
With the Mauser-style actions built by CZ, Winchester (some model 70s), Ruger, Kimber and others, you can simply move the bolt a fraction of the way forward and pull it back again to solidly pick up and eject a round. I do also find that the bolts are generally less sloppy in the action, as the long extractor acts as another guide to keep the bolt going forward and not sideways.
These sound like silly points to favour one rifle over another, and they are. Although it’s a feature I really like, it wouldn’t influence which rifle I bought if I was choosing between two (unless they were otherwise identical, which isn’t going to happen).
If you want to dig a bit more into the subject, there’s plenty on the web, including this well-illustrated article at Lucky Gunner.