In the Westley I owned, the claw never had any issue at all. The overall length of the cartridge is very important to confident pickup though.
Meaning, if the cartridge fills the magazine front to back, as the bolt is sliding forward the rim has nowhere else to go than under the extractor and against the bolt face. The bullet end of the cartridge is well on it's way up the spout before the rear end comes up to fully nest in the bolt face and under the claw.

The real art of making a 425, 500Jeff or rebated Schuler feed is tuning the rails to allow the cartridge to come up enough that the bolt face meets the cartridge to push it forward without letting the cartridge eject out of the action. Thus the "clips" on the Schuler Jumbos and most of the Westley 425s these being the two biggest bodied of the rebated cartridges.

It's easy to imagine that a fat, rebated cartridge has to come up higher to allow this and the only way is to widen the rails - to a point.
WR designed their clips to hold the cartridge high and centered and Schuler used one clip in the right side of the magazine to push the cartridge against the left wall under the lip to keep them in place.
Of course, all rails are wide enough for the cartridge to pass freely through and the brilliance of the Mauser staggered magazine, stepped follower and strong magazine spring are keys to it all working too.