Last year my friend and both acquired Bartlein 30" 1 in 7.5 twist 5R barrels to shoot the DTACs. Dan built a 6mm Super LR and I built a 6mm-284. We discovered that we couldn't get the DTACs to shoot! We tried a few different powders, seating depth changes, neck tension etc nothing worked.
In my search for another bullet I read in several threads that the hunting 115 VLD wouldn't be able to hold together with such a fast twist. I did hear that the 107 sierra could handle it even with high velocites. Tried the 107 sierras and ended up finding a good load quickly.
I want to warn you that 3 groove barrel will begin to destroy bullet jackets once the throat gets rough. I know because I own two 3 groove barrels. Combine that with a fast twist and it happens pretty fast.
I was ill advised by the barrel manufacturer to get a 7mm barrel 1 in 7 twist in a 3 groove. Berger 180 VLDs began to come apart at around 225 rounds! Switched to the 180 target VLD and they began to shoot poorly when the 7 rem mag round count was around 400.
The 257 weatherby 3 groove was more forgiving shooting the 115 VLDs well till round count 500.
The only solution to continue to use these rough barrels was to go to a mono like the E-tip, Barnes or GMX or a bonded bullet. I chose accubonds in both situations. Lost quite a bit of BC and learned my lesson.
Back to the 6mm-284. Just a few weeks ago I tried the new 105 hybrid. With its .547 BC it is very competitive with the DTAC in actual downrange performance and will beat the 115 VLD. I am very happy with the performance. I don't push the 6mm-284 too hard and was running them at 3400 fps with excellent accuracy. The barrel has 800 rounds through it and it still shoots bugholes.
I hope you can get the DTACs to shoot. I understand Sierra makes them for Dave Tubb and they are stout. If not you might have to go to a heavier jacketed target VLD and skip the 115 hunting VLD.
As for using the target bullets for hunting there are quite a few guys doing it. I bump into threads from time to time. The new hybrids are called target bullets and I am certain you have read the stories of hunters using the heavier bullets in 30 and 338 calibers with fantastic results. The tips are the same just the bearing surface is thicker. I have no idea how the new 105 hybrid will work on larger game but I will certainly give them a try on coyotes to get a clue. I'd bet with good placement it will flatten an antelope or our smaller coues wt.
Please let us know your results with the DTACs. These forums are the best when it comes to sharing experiences. I look forward to your report.