Thread for moderator ?

[Waterworks]

What would be the best design for a thread for a moderator, to achieve a consistent true to the bore lock up?

Can a threaded component achieve this without some kind of locating shoulder/ sleeve ?

Would a taper thread lock up more precisely than parralel one ?

 

[steve-l]

Why are you reinventing the wheel? Secondly, a thread never provides location by itself. Location is always provided by a shoulder or other locating surface. That surface or surfaces can be a flat or a tapered face. Consider that a thread is simply a self centering angled face in a spiral. That plus a perpendicular 90 degree trust face is more than adequate. consider lathe spindles and drill pipes joints as examples of what works.

In the case of clipping, the cause is usually a poor thrust face that is not perpendicular.

 

[tobnpr]

Bingo.

Threads bring the parts together- shoulders align them. This is what's important- having shoulders precisely faced 90 degrees to the bore/ receiver raceway.

I laugh when I see threads with guys bragging about "lapping" their tight-as-a-gnats-azz tenon threads to the receiver.

 

[GGaskill]

The bore is not always perpendicular to the muzzle; most of the time but not always. So you should check for that condition before machining the alignment shoulder, and then, make the shoulder perpendicular to the bore, not just perpendicular to the long axis of the barrel.