My opinion on the 150 gr 270 bullet is it is very explosive up close but a good bullet at distance. If the 300 is built about the same should be devastating with the mass it has!
I have heard this quite alot, and I think it would be a good option specifically for the Lapua and Norma type cartridges due to the lower initial velocity, 2650-2800 fps
Was your experience with the 150 .277 out of one of your Sherman designs? If it was, that would put it near what, around 3200 fps or so if I recall right....(sometimes I miss in that department ha ha) I could see it causing frag issues, being a softer design to still expand down to 1300 fps, and impacting at like 3000 fps in close.....LOTS of explosive properties ha ha
This last year, the average range we took game at was between 550 and 650 yards or so, and starting at say 2750 out of that .338 Norma, I think would put it in ideal impact velocity for good bullet performance, and even a close range impact would likely be below 2650 fps or so, I think it could work well for these type of cartridges....
Now throw it in a .338 LAI or a .338 Allen Magnum or something, and you will have explosive consequences in close ha ha though large/specialty .338's like these typically aren't used very often in close.
Another consideration is effective range, essentially all the 300 grain .338's bullets run out of effective on game range when they drop below the expansion threshold of 1600 or so fps, though they still have well over the generally accepted 1000 ft. lbs of energy. Lower that to 1300 fps with the ABLR, and you just extended the effective range of that cartridge, and a 300 grain at 1300 fps still has 1125 ft. lbs of energy. Though out of these cartridges, by the time it drops to that velocity it is somewhere in the 1600-2000 yard range, so it may not even be considered a benefit to many people, as game won't be taken by most at these extreme ranges. Just something else to add to the discussion ha ha
I think, if it is constructed like the other accubond LR's, could make for a great all range bullet in 2650-2800 fps mv .338's.