Is there a way to convert .50 bmg brass to .55 boys brass ?
I realise that .55 boys has a belted case, however was thinking I could use the .50 bmg brass just the same.

Thanks in advance for any replies.

Cheers Morton

I suppose it could be done. The cases are dimensionally similar. The problem would be the .55 boys case headspaces on the belt where the .50 BMG is off the shoulder. The other consideration would be how you would stretch the neck of the .50 BMG case without damaging the case. Would it not be better to rebarrel to BMG and put a similar profile on it.

just my 2 cents.....

Depends on how hot you load them after they are formed.Explanation. You can anneal bmg cases
to expand that much real easy, Rob and I take
them up to 12ga, 700. cal. Now if you have a
Boyes with good in specification chamber
then take bmg case, expand mouth to about
60 cal to get a wedge fit when you close the bolt. It has got to close real hard. Use 60gr
of shotgun powder and farina filler with
a wax or playdough plug to fire form.
Most important get a Lake City bmg case and section it so you can see the long strong radius and don't use any brass brands that has shorter corner radius tham lake city, if you use unfired LC cases usually the first factory
annealing is enough to get to 55cal and shoulder
only has to go out about .005" The long corner
radious of LC case will support bottom of case just above thr groove where the belt recess
is in the Boyes chamber. Formed cases should
handle 50 k loads.Ed.