Franklin Bradshaw said
Nephew has a tube fed mod 77. He says it’s bolt doesn’t lock open. I was wondering if it does ?  

Hi Franklin,

Some of the later Model 77’s have a “bolt hold-open” feature which is a small button on the barrel directly in front of the receiver on the right side.  Not all 77’s have this feature though as it was implemented sometime during mid-production.  A description of it appears in the 1960 Winchester catalog.

If his 77 has it he simply has to retract the bolt and then push down on the button and gently release the bolt while holding the button down.  The bolt should then catch and will be held in the rear (open) position.  It is a completely manual operation and the bolt is not automatically held open after the last round is fired.

Again, not all 77’s have this added feature though, only the late production models.

Hope that helps.

Regards,