They are a ballistic tip type bullet designed for target shooting. I have used them in the 75 grain .224 and the 105 grain 6mm. Both of these are "VLD" type bullets. Interestingly, both of these bullets are also excellent mediumbig game bullets. They reliably penetrate through the ribs, and then explode - destroying the lungs. In the hands of a skilled marksman, and on broadside rib shots only; these are some of the most lethal bullets ever produced. There is an article by Horace Gore in the "Journal of the Texas Trophy Hunters" about the use of these bullets on trophy whitetail deer.
www.ttha.com
And their accuracy can be pretty spectacular. A .22-6MM I built in 2002 has produced 5 shot groups of 1.7" inches at 500 yards with the 75 grainer.My personal 6MM-284 with a Jeff Lawrence 1:9 barrel shot 1/4" for five shots at 100 yards with the 105 grain A-Max. They make these in medium weight .30 caliber bullets, but I haven't tried them yet.