The 408 cheytac holds about 160 grains of water and the 416 Barrett holds about 200 grains of water. I have no idea what a 416 Vestal holds.
The accuracy trend of short and fat is where it's at started around 20 + years ago and now in ELR alot of the newer cartridges are moving away from that but the gains are not there.
The 222 was replaced by the 6ppc. We have the 6BR as well. The 308 replaced the 30-06 the 300 wsm replaced the 300 win mag and accuracy got better.
In ELR which is still in its infancy everyone is searching for velocity due to the distances we shoot at. In the future I think accuracy will end up winning all the matches not velocity.
If we take the 375 cheytac as an example it shoots very well for most reloaders at xxx powder charge. If we step it up to the next node the brass falls apart immediately so to reach that next node we create the 375 Snipetac which operates smoothly at that same velocity but without ruining your brass on one firing or the need to hammer open your bolt.
All of these variants are designed to reach that next velocity window or to get you there without the need for a larger action required by the larger diameter boltface.
As these cases keep getting longer and longer they become less efficient meaning we are burning alot more powder for a small gain in velocity.
Eventually it is my opinion this sport will go through a series of steps then settle down to 3-4 dominant cartridges that will push a moderately high bc bullet around 3050 fps but do it with pin point accuracy.
The blue gun in the picture is Lynns 375/50BMG in a McMillan super benchrest stock. His load is around 206 grains of VV20N29 with a 400 grain bullet and it has won a ELR match in Nevada so it does shoot accurately but barrel life is around 350-400 rounds.
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