Max load????

I am loading a 243 with 38 grains of IMR4895 pushing a 85 Grain BTSP. In my Lyman book it says this is a max load and produces 49,600 PSI. But when I look up the load on the Hodgdon site it shows a max load of 36.8 grams of IMR4895 with a 85 grain Barnes TSX producing 58,000 PSI. Is the smaller grain because of a larger Barnes bullet due to copper weighing less than lead????

That seems like a big difference in grain and PSI to me from one bullet to another.. How do you all select your grain weight if you can't find load data for the exact bullet that your using??? Or am I just being overly paranoid?

I have shot these loads out of my 243 and had no issues.. Just curious why there is such a huge difference in grain and PSI.

Barnes bullets make higher pressure.. I'm guessing its the solid copper

Yea, I think I read somewhere that it has to do with the hardness of the copper, and the resistance aginst the rifeling.

Could be way off, but makes sense.

Paul

Could be shape and amount of bullet touch. If the barnes is longer and has a longer contact area then the higher resistance should create more pressure. From what I can remember of my barnes triple shock in .270 it is a longer bullet than my hornady of the same weight. The barnes also has more canneluers than the Hornady.