I have experimented with the old barnes X bullets and did not like them. They were not accurate and I had pressure problems due to the fact that it is so much harder to compress a solid copper bullet.
I tried the new Triple Shock bullets when they first came out and the pressure problems went away, due to the the machined rings (less material for friction with your barrel).
The accuracey seems decent in my .257Wby (115gr TSX @ 3,350fps) and in my .300Wby (180gr TSX @ 3,200fps).
I chose these bullets, because I did not want bullets disintegrating at close range. I shot an elk last year with my .300Wby at 70 yards. Blew off the top of his heart. He went 70 yards down hill and expired. Ofcourse the bullet went out the other side and was not recovered.
Shot another elk in Colorado, hit him somewhere in the chest cavity from about 200 yards. He was going up a steep hillside covered with oakbrush. When he was hit, he rolled over backwards and died as he hit the ground. I was surprised he expired so quickly. I never did try to recover the bullet or even inspect for the entry/exit hole. I was too pissed off after pushing/ fighting my way thru the thick oak brush trying to get to him and planning how I was going to haul him out of there. I finally figured how to get him out, in small pieces.
Shot another elk in the neck at 480 yards with the .300wby, hit the neck bone and he collapsed in his tracks. Bullet was recovered and pictured below.
Used my .257wby to shoot a mule deer in Ca. at the same range , 480 yards in the neck (what a coincidence), it collapsed in its tracks as well. Bullet pictured below.
Using my .257wby in WY on a high country mule deer hunt I shot a buck from approx. 500+ yards (before I got my range finder). At the shot the buck dropped in his tracks and did not budge. I could see him thru my binoculars, just laying on a patch of snow not moving. I watched for several minutes making sure he was not getting up. I then glassed 2 of his pals that came running toward me, to see if I could study their reactions, but never could locate them again (their reaction was to hide really well). I then glassed back toward my downed buck only to find him missing from the scene. What a nightmare. I glassed all over but could not spot him. I started walking up the mountain toward his location. At approx. 300 yards, I saw a doe with my naked eyes. I thought, what the hell is she doing here after I just shot that buck. I then put my binoculars on her and saw she was sporting a nice rack and looked like she had just been shot by a barnes TSX bullet. The buck made the mistake of trying to go across a wide opening right in front of me, trying to get to the next slide, I led the buck, took one shot off hand at approx. 300 yards and hit it in the neck. It collapsed in its tracks. I inspected the first shot and it was exactly where I wanted to put it. The bullet entered low into the near armpit and exited out the top of the far shoulder (the buck was still way up above me, that's why it entered the low armpit and exited top far shoulder). When I opened him up, there was extensive internal damage. I don't know how this thing was able to get up. Those WY bucks are tough as nails and cling to life very well.
In conclusion, it seems that these bullets are lethal on neck shots.
I will keep using them because they are accurate in my guns.
I have tried switching to the Accubonds, but they only come in 110gr for the .25cal and my rifle does not shoot them well. My .300Wby likes the TSX just a little better than the Accubonds, so I'll probably stick with the TSX. 180gr Hornady SST's are accurate in my .300wbv, but I don't know anything about how well this bullet would hold up on close hits on elk?
Thats my experience with these bullets. You can draw your own conclusions.