ok, my story I shot a 6.5 gibbs with a 30" 8 twist kreiger, I run 140's at around 3200 fps. When I first used bergers in it, there was no orange box hunting or yellow box target, there was a thick and thin jackets, I found a box of thick jackets somewhere and the accuracy was excellant, so I went hunting, only had 1 shot opprotunity, a doe at 419 yards, held for a doule lung shot hit her where I aimed, she ran 40 yards, that bullet exited almost the size of a quarter. before the next season I ran out of bullets, so sent my better 1/2 to the gunshop to get some, well they had changed them the way they were packaged, the guy running the shop, even though the mrs had the part number talked her into the orange box, well accuracy was again excellant so I got the charts tuned, rifle sighted in and went deer hunting, catastrophe struck, shot 3 deer with it that fall, ranges were 230 yards, 457 yards, 493 yards. never found the 493, lost him after 1.5 miles of tracking. the 457 I found the next morning after 1/2 mile of tracking, the 230 yard shot was a doe, she piled up after a 100 yard sprint, here is what the 2 recovered deer had for entrance wounds
as you can see total penetration was 2" or less on a lungshot, have never skinned a rib shot deer that didn't at least have a hole into the chest cavity that was visible.
so I ditched the orange box, sent the mrs back to town for the yellow boxed match bullets, once again the guy didn't want to sell them to her, cause she told him I was using them for hunting bullets, he even had her to call me and ask, then he got on the phone and was telling me the difference, so told him to tell the mrs forget it, and hung up, and ordered a yellow box online.
This year I used the yellow boxed match bullets they accounted for 5 deer, 4 of which were drt, one took a 40 yard sprint, even on not so good hits, they disrupted enough tissue and sent enough fragments into the vitals that the deer just took a dirt nap.
this was a 140# 3.5 yo 8 point, chasing does, was a bad hit, 3" below the spine at 370 yards, he never moved after the report
here is the damage, even the spine was broken, lungs were pepered with fragments, liver was totaly shredded.
decent buck for this area.
So near as I can tell my fast twist cut rifled barrel, just engraves the thin jacketed hunting bullets too deep causing violent premature expansion, however in this rifle the thick jacketed match bullets perform like the thin ones do in a different barrel.