Straightshot,

You will need to spend about $35 for the Centerfire Nozzle, difuser, and contact tips (pack of ten) to convert the M-25 gun to centerfire Bernard frontend. You may do better depending on where you get the goodies.
I ordered mine from Cyberweld. (haven't got mine yet) http://store.cyberweld.com/becemigcoq3.html

Here is link to the parts needed.

http://www.bernardwelds.com/products...ion_chart.html

Enjoy,

Tim