i'm just starting to reload and the bullets i intend to hunt with i'm having trouble finding data for. cast performance 275 gr. plain base with H110. WW case Win lp primer. one manual i have shows 270 gr. gold dot with this powder. can i use this data since the pressure will be lower with a cast bullet compared to a jacketed bullet? thanks for any help

Use the data for 300gr & work up.

Yes.

Go to Beartoothbullets.com and look at their data. They have developed some very accurate loads for the LBT designs. I have replicated their 280gr. LBT/ 12 grain #5 load and have found it to shoot 1" groups as advertised.