It seems from what I've read that guns either love or hate the LR ammunition with "Most" guns liking the LR ammunition. Those that do report that they are nearly the most accurate bullets they have ever used. Some report that they are better than perfected handloads they have developed over years. However it seems that there are a minority of guns that just hate them and they are the worst accuracy they have ever seen.
I was wrong on my earlier post above. A person named "Bigred" on the Marlin owners forum has used the new 308MX with the Hornady ammunition to kill and elk at distance and at least one deer at something like 365 yards as well as other kills.
I also have read many, many, many reports of excellent terminal results from the use of the new LR ammunition. Some reports are that it performs better than any ammunition they have ever used. I also have read that the gummy tip breaks up and the bullet has separated from the core but the deer is dead. It seems like the gummy tip acts like a hollow point and expansion is immediate and pretty dramatic. The separation may be from the expansion being too much of a good thing and it keeps curling back to the point that the core becomes exposed.
Personally I have not tried the LR ammunition. I use a 35 Rem and the Remington 200 core lock works just fine for my 50 yard shot I get at deer. Unless I hear some more reason of terminal performance being superior to the factory 200 core lockts, I see no reason to go to the gummy tips as I surly do not need the extra velocity and "flatter shooting" when I only get a shot between 50 and 100 yards!
Three things that do you no good: Runway behind you, altitude above you, and fuel left at the pumps!