better to ask than do something dumb

[Bassfish1952]

Think I may understand where you are coming from. Yes heavier, all else being equal does better at retaining energy down range, Weight & ballistic coeficents enhances down range energy. That being said am not aware of Tungsten being employed as an alternate core or tip. Tips as I know them are composite & there size even in tungsten would not provide significant weight.

For all typical 6mm ARC applications 2.260 OAL will be the maximum cartridge length due to magazine limitations. Should you care to study the load data w various bullets, you will notice diffrent Over all lengths (OAL) bullet dependent. the point form controls max OAL due to differences in where the rifeling lands may contact the bullet. study up on throat length if you wish to better understand.

Anyhow, All copper bullets do give up weight & generally ballistic coefficient as well. So yes lead core bullets with high BC will retain more energy down range.

All copper bullets generally w most of todays designs are dependent on more velocity for proper expansion. Thus the monolithic bullets are more favored in the higher capacity cartridges. Im setting my goals for impact velocity of 2400 fps plus.

Expect at least one bullet design may perform well at lower velocity. may wish to study up on Lehigh Defense Controlled Chaos Bullets.

Thanks for your answers
As I have said I know nothing about this just asking. I did start hunting again this last year and eat deer normally 5 out of 7 days for lunch and dinner. My doctor thinks after gastric bypass surgery my diet needs protein and deer is perfect for me. That said I have noticed pieces of bone ? or bullet in some of the meat and had read about lead from the bullet. 
The shooting I have done does not go past 300 yds so using my cz527 rebarreled to 6arc I want to make sure I have the best round to make a clean kill and leave the meat clean too.
I have spent most of my life as a bass fisherman and in fishing tungsten is in use a lot to replace lead so just asking.
Hornady has the 80 and 90 gr CX but nothing larger that's why I was asking about heavier bullets and length