That type of failure isn't technically a stovepipe, it's usually called a missfeed. The most common cause for this type of failure are magazine feed lips that release the cartridge too soon, before the nose of the bullet has entered the chamber mouth. Sometimes the feed lips can be bent a little tighter to hold the cartridge in position a little longer during the reloading cycle. Another cause for this type of failure, can be an extractor that is functioning improperly and inhibits the case rim from sliding under the extractor's claw. This causes the nose of the round to tilt upward excessively and miss the mouth of the chamber.