What are some good flints for a flintlock, and what size would a lyman flintlock use?

IMO, Tom Fuller hand knapped black English flints are the best...(and they're the real deal).

You order flints based upon the width of the frizzen...ie: my TC Flintlocks are 3/4" wide and I use 3/4" BEF's...(your's may be the same size)...and I average 40-60 shots per flint.

I've always bought mine from October Country in bulk bags of 50 or 100 to get the lowest price/flint. ( www.octobercountry.com )

I use the 3/4 inch Tom Fuller Black English Flints.. same one I use in my T/C Hawkins also. I buy mine from the same place Roundball does (in fact he was the one that told me where to buy them from) and as usual as Roundball claimed, they are excellent flints.

I've been buying black English flints from Track of the Wolf, use them in all my flinters. Very long lasting.

Same here.

I used to buy the ones from T/C when I first started,but they are terrible.

3/4x7/8 black english flints for my t/c flinters like RB states getting anywere from 40 to 60 shots on one flint