no1 mk3 crooked brass

[Peter Laidler]

To ascertain exactly what and where the problem lies, you need to get yourself a .074" reject CHS gauge.

Knowing that the gauge is an exact known quality, smear the base with a coating of engineers blue. Now close the bolt while you have your finger on the trigger and allow the bolt handle to close the bolt head onto the end of the reject headspace gauge. It won't close fully....., don't worry, we don't want it to.

Now undo the bolt, remove it and inspect the face of the bolt head. You might find that the blue mark is only part or half way across the face of the bolt head. This indicates that the bolthead face is not square to the breech face. That is your problem.