Question for those that have the Viersco Dies

[jbs2014]

I have the RCBS 50 BMG press kit. The 50 BMG sizing dies fit in just fine so do standard dies (with the adaptor) the problem is the Viersco 375 and 408 CT dies are too small for the 50 BMG and too large for the included adaptor. What sort of thread adaptor bushing do I need to get? The press is an ammomaster 2.

Any help would be appreciated.

Thank you