I’ll keep away from too much technical stuff because I don’t have the bullet configuration. So let’s deal with what we know and take a line through the recent Belmont experience of some, seeing it’s our National Range.
The first thing that comes to mind, is when do we pull out the big gun? Is it past 700 yards when special tuning characteristics are required or low SD’s because we have to be mindful of its limited barrel life and window of opportunity aside from the cost factors? You will have to develop your tune on rations due to barrel life if using it on ranges at full throttle. If you are not using the full throttle to reduce velocity, then you jeopardize the high load density required for slow burning powders to be efficient and your ignition and elevation will suffer particularly at long range where you want to use it.
The bullet weight demands slow burning powders in this bore size which unfortunately have short nodes due to slow burning powders as Keith has said. Leading you to doubt your tune and mistakenly do more testing when you fall off the node in variable air densities. Also, trying to find the correct powder if it is not slow enough can lead to muzzle waggle. Testing eats up more rounds.
Muzzle waggle can be reduced with reverse taper barrels, a long heavy weight behind the muzzle to stiffen the barrel or simply reducing barrel length to about 26 inches. The latter solves the powder density issues and will allow you to conform to muzzle energy limits.
Muzzle energy limits, further complicate powder density issues in the cases for which the bullet was primarily designed for use. In cases with less capacity, it will pressure them and reduce case life. This means you will be running in new cases for maximum performance of the case which you need at the longs to reduce SD’s. If velocity is reduced then difficulty will be encountered with frontals at venues like Belmont given the high mounds. There are other related reasons I will come to.
Assuming you have a throat reamer and can take out the throat, how much do you take it out? A jam won’t work because you will pop primers and be forced to run with a reduced load with a heavier pill. Testing eats up more rounds in an effort to reduce pressure spikes. This is not a primer problem.
Will a much longer throat interfere with the bullet exit timing and so will finding the correct tune become harder?
Does the heavier bullet exacerbate the upward lift of the barrel and create greater rifling torque thus upsetting optimum barrel indexing in the vertical plane, not to mention bag handling? The muzzle movement might offset a positive compensation tune given the greater barrel lift on the longer whippier barrels people are currently using.
Where the Belmont experience hits home, is in the turbulent condition, with a long nosed projectile constantly trying to re-orient itself with the wind flow. Alan has hit the nail on the head. The BC won’t matter because it is a very long VLD from his analysis.
Additionally, because it is longer, it will require a faster twist rate to stabilize it. This also reduces velocity. The shooter might use less windage because of a high BC, but from the drift diagrams below reveal, they will have to become experts at winding the elevation knob because the higher twist rate steepens the angle of drift in higher winds. The trade off has to be found. The Belmont experience was not good for those with poor elevation. Other reasons were discussed on a previous thread. The diagram does not represent actual figures and is merely posted for conceptual purposes. You should again look at Peter Smith’s site and download his simulator for practice with spin drift.
Because I have not got the specs for the pill, I can no give an exact point for the peak of the trajectory. From the second illustration in the diagram, you will note, nose wobble or yaw, starts to be a factor past the overturning moment. That’s where these big long noses get into trouble. A much faster bullet can extend the distance the overturning moment takes place. The second illustration in the diagram shows the yaw is very stable about the overturning distance and implies accuracy is too. It is very much velocity dependent.
Of course a bullet that is shorter, requiring less twist maybe better if it’s BC can be gained from its diameter for the use in long range tough conditions. Again the trade off has to be made between the slower twist with lower recoil and the higher recoil of a wider bullet if you want the same BC. Denis’s contributions are valid here.
The bigger bullets will extend the coning range a tad. I think it’s important to develop loads at the end of the coning distance. This is why I think 100 yard testing can be misleading with boat tail bullets. The longer bullet will have a longer boat tail and exposes greater surface area of its angle to other factors causing in-bore yaw. Unless the smithing is spot on and you load concentric cases, you could add to problems. While 600 appears a go range for testing due to the yaw stability, it is subject to too many other variables in weather for load development.
In conclusion, the FO will find the most efficient kit and so form parameters like all disciplines but determined from a different path because people will copy the best and in doing so it will set the benchmarks for the class. This will give effect to the maturity of all classes shooting on our venues. Longranger makes a very good point about supply, as does Macguru about the 90 grain 223 and Matt with regard the 6mm in 115. It’ll be hard to toss a 180 in 7mm across the course. David.
Won't be long before we see the advocates lining up for a rifle weight change due to recoil and faster twists. I got very bored using the machine rest, except to say the data was enlightening. 
. But its just coincidental that my arbitrary choice of a 1mph wind reading error and 1000yards shows the 195 in such a good light. In the vast majority of situations, the advantage of the 195 will make no difference on the scoreboard.