Each lot of DTACs are tested with several 10 shot groups at 200 yds in the tunnel to pass the accuracy spec test which is the same today as was it was 15 years ago.
Specific lot # variations in OAL are typical with the pointing of the bullet. Some noses get closed slightly better than others. A lot depends on the operator and the initial lubrication of the jacket IMO.
If you are looking for the ultimate accuracy (and an explosive hunting bullet) from a DTAC try some with the NOSERING application. Available from SSS.
The NOSERING application on a DTAC rivals the 1% BC spread of the currently advertised partially closed tip Berger. The NOSERING also allows the bullet jacket tip to fail into the lead core upon impact. Impressive to say the least.