Quote Originally Posted by Hsing-ee View Post
Just found a bolt/nut from a BSA Mercury-S which might work, either with a collared nut or by countersinking the breech jaws a bit. It is a loose fit in a HW35 breech block, so the HW bolts must be 7mm not 6.35 mm, and would need the breech block to be drilled....

The BSA bolt is too short so I've ordered a shouldered bolt off the evil bae...
Bowket used to include a bolt in his 12 ft/lbs Meteor conversions (£23.50 in the early 1980s) and also offer them fro Wobleys. He copied the HW system by threading one jaw and boring out the other. The bolt he made had a 7mm shank and the breech block/barrel bored out to suit. The HW system with locking screw or nut is the way to go. An unlocked bolt can turn around in use giving a cam effect which alters zero. I know this to be factual as I used one for many a year. Wish I still had it.