How many guns are we talking about here ?? In the least . . in the hundreds.
These guns would have to be taken out of service on a rotational bases. A few at a time.
These guns are sniper rifles so nothing could be done in the field or even at some rearward base. These weapons (the Navy and USMC guns) would have to be sent back to Crane,Indiana.
The scopes,bases,and rings would have to be removed. The bbl and gas system would have to be removed. Then the 6.5 bbl would have to be fitted,gas system added and headspaced. If called for,a new muzzle device would have to be added.This work would most likely be done by the civilians working for the military at Crane.
The weapons would most likely have to be tested for reliability and accuracy. Load testing would have to be done. This alone could take awhile. Snipers do not grab a handful of ammo out of some green ammo can.
Depending on bullet chosen for the 6.5,mags could have to be modified or newly produced,depending on how the internal ribs were located to support the 6.5 bullet chosen.
Then . . . the return to the fleet. The end users would need training. They would have to shoot their weapons in order to compile their crib notes of drops and wind drifts.
So . . . depending on the distances of my targets ( all these 1000yd shots that people love to talk about are few and far between),if it were my choice,and I have gotten used to my 7.62,I just might stick with it.
You will never hear . . the military will never release the info . . for obvious reasons . . but take a guess how far the AVERAGE of the last 1000 sniper shots were. Think about it. ---- SAWMAN
Probably in line with your response is why the military has been reluctant to change our the 5.56 for something even though they have talked about and even tested out such rifles.
I will not be getting a 6.5 creedmoor. I do have a 6.5 grendel for the ar15. It did and will cost me more for sure.