makerbullets.com lists solid copper 200 grain bullets for the .35 Rem. Barnes has TSX and TTSX .358 diameter bullets in solid copper, but they are not suitable for Marlin tube feeds unless loaded one in chamber, one in magazine. Most Barnes need more velocity than .35 Rem provides. Factory .35 Rem are loaded to 'low' pressure, 35000psi compared to most other cartridges. Just pulling bullets from factory cartridges and replacing them with something different is not recommended ('Mexican match' is something else). Actual load development is needed, with the rifle to be used. I did not see what rifle you are using? Found the mention of a 336, OK. With care, you can speed up the 35 Rem in the Marlin 336 quite a bit. Buffalo Bullets gets 2200fps with a 220 grain Bullet.