Mike Venturino did an article on this years ago, using dowels, and just like the Norma test, their was no difference in bullet deflection. Any bullet fired through brush will deflect. IIRC he was using the .30-06 with 180 gr bullets. Also years ago Layne Simpson did an article on hunting Moose in Sweden with the .358 Norma Mag. He put a 286 gr semi spitzer bullet through about a 2 1/2" sapling, and dropped a bull moose. The article had a picture of the tree.
For penetration in the brush on big animals with the .270, I'd say the 160 gr Partition Semi Spitzer would be optimum. Round nose bullets won't magically cut through the brush, but they do penetrate like crazy even in a plain cup and core design. Before I started handloading, I used Winchester 180 gr Power Points in my .30/06 on S Sask Whitetail, and Mule Deer, and I can't ever recall needing more than one shot to drop them. I didn't know about ballistic tables, just sighted it in at the gravel pit for 100ish yds and went hunting. A good .270 factory load would be either the Remington or Federal 150 gr Round nose SP.
As far as FMJ goes, as well as the Hornady, Remington has a 115 gr made for the 6.8 SPC. It might be a good bullet for coyote hunters hoping to save the pelt, but other than plinking wouldn't be legal or really useful as a hunting bullet. When WSS in Calgary moved to their new store they had loads of bulk 115gr FMJ's for sale, wish I would have bought some, just to try them out.