Magnum replacement heads

guides ok do first if necessary
cut the guides for viton seals
put a cross hatch on the stems with some fine wet and dry i USE A SUNNEN STEM HONE
if you have the tooling ask PRH or seat cut, next cut slightly narrower, then a couple more till your plunge cut but the next do not have to be wide
just slightly better to split the 45 to 60 in half and same going to the top cut
If I am not current PRH please straighten me out
having used the Serdi makes me lazy