Greg:
The term 'sealing' that you use IMHO is incorrect, or mis-used. The five thread requirement in classified use of RGC is to provide a 'controlled escape pathway' for ignited products of combustion that are within the RGC. The 'pathway' is supposed to allow the gasses to cool while venting thru the threads to prevent an 'explosion' in the area.
Or, am I still missing something...
