303 HPBT 174 Gr.

[waco16]

I've had some really good results with the Sierra bullet in my No4T (see pic).
Using neck sized HXP brass containing 43 grains of R15 it gives me pretty much service velocity.

I also got very good results from the Hornaday flat based bullet but thats a soft point and over here in the UK you have to have special permission on your Firearms certificate to have those now.