Can you use any mast with any make sail? Nope, not sure about that? Sail manufacturer have different speck. Hard top. Constant curve, flexi top? Whenever a shop has sold me a mast they have never asked what sail it's to be used with? Just wanted to sell the goods hey? For example, gasstra sails use a hard top mast. If a shop is selling you a mast, check it's ok for for the sails it's to be used with 
Many thanks your advice pm... I had a conversation with a np team rider today who said exactly what you mention on my questions
I will actually have to get a 430 Sdm mast with 48cm ext to work correctly with my 6.9m firefly
Also discovered it was not the best sail for a beg/int sailor on flat water as more a wave sail....
As you say it is important to do your homework before getting caught up in a sales pitch. .... 
That's cool. Don't forget these shop's are running a business to make $$$$$. Every mast I have purchased over the years the shop has never ask what brand of sail it was for? Did my home work and found out myself. Good luck.. 
Select to expand quoteplumberman said..
That's cool. Don't forget these shop's are running a business to make $$$$$. Every mast I have purchased over the years the shop has never ask what brand of sail it was for? Did my home work and found out myself. Good luck..
I have come across shop assistants that didn't even know that the mast was supposed to match the sail.
The thing that pisses me off is that the sail makers constantly seem to change the mast types required for new season sails leaving you with mismatched kit or having to buy new masts when you upgrade sails. My masts have always outlasted my sails so rather than cave to this paradigm I have opted to buy sails that will match the masts rather than sails that don't work properly on older masts...
Select to expand quoteSmithy said..
>>> My masts have always outlasted my sails so rather than cave to this paradigm I have opted to buy sails that will match the masts rather than sails that don't work properly on older masts...
Yep, I have 20 year old 70% carbon constant curve masts, and have stuck to constant curve sails since.
If sail manufactures want to do "funky" stuff they've lost me as a customer.
Select to expand quoteplumberman said..
That's cool. Don't forget these shop's are running a business to make $$$$$. Every mast I have purchased over the years the shop has never ask what brand of sail it was for? Did my home work and found out myself. Good luck..
You have to wonder if they sail on the products they sell ?
One of the most important choices you make when rigging a sail is which mast you put in the mast sleeve. Or, more specifically the length, curve and stiffness of the mast, and how closely these parameters match the sail. The mast is quite literally the backbone of the rig and it governs the sail's performance.
