7.62X51 bolt head ID

[Peter Laidler]

The problem with using s converted .303 extractor on a 7.62 rifle is one of geometry. There is a greater space between the bolt face of a .303 than the 7.62 and the start of primary extraction takes place later during the lifting of the bolt cycle. This is also a primary cause of hard extraction in civilian home conversions. That's why the extractors differ.