Help front sight setback mk4

Help! I have a Bubba-ized mk4 no1 that I want to restore. Someone has removed the front site.

Can someone please tell me the proper setback distance that the front sight ring should from the end of the barrell. i.e. measured from the end of the barrel to the begining of the sight base.

Also, what is the distance from the end of the barrel to the beginning of the forestock.

Thanks

Tom

The front sight block is held in place with a pin, therefore you should have a notch in the top of the barrel to hold the sight block in position. (item 10 or 22 on parts list)

The front sight base is secured by a tapered cross pin. If your barrel hasn't been cut short you should see a groove for the pin 2.2" back from the muzzle.