Another option to muddy the waters....
I shoot a 6.5SLR. Had a .260Rem too, and they are almost identical capacity-wise.
Since my 6.5SLR is a 15# rifle, and the .260Rem was a 10.5# rifle, I rechambered the .260 into a speed demon 6.5SS for hunting strictly due to the weight, and kept the 6.5SLR for steel and LR varmints/mid-range deer. The .260Rem was fully capable of pushing the 140 HVLD @ 2865 w. 42.0gr H4350 into the .2s @ 2.188" CBTO (mag length) from a 26" 1:8" Bartlein #3b.
The 6.5SLR is basically a .260 case with the neck & shoulder of a 6.5x47L. Best of both worlds. I get 2850 from a light charge of 41.5gr H4350 w. 140 HVLD. My hunting load is 43.0gr H4350 @ 2960fps with no pressure. Both shoot into the .2s and usually less. I have had quite a few 5 shot groups into .0-.1s. I had 3020fps, but not as accurate, and fairly hot. But this rifle shoots most bullets well. 140 HVLD, 140 Hybrid, 142SMK, 127 Barnes LRX, 130 HVLD, 85 V-Max, 139 Scenar L. Only 2 bullets it doesn't like as much that I have found. 142 NABLR & 143 ELD-X. Those shot .5-.75MOA. The rifle has just over 1900 rounds down the barrel, and still shoots in the .1-.2s.
Brass is easy to form. Use Rem or Win .243 or .260 brass, and it is a no-turn neck solution. One pass through the die and you are 95% done. Fire form loads were no different in mine than fully formed cases. I have 8-9 firings on my 200 target load cases. My 100 hunting cases only have 1-2 firings on them.
Use Lapua, Norma, Nosler, Hornady, etc., and you will need to turn necks since shoulder and neck thicknesses in the brass will cause a donut.
L-R: fire formed 6.5SLR, FL sized virgin 6.5SLR, .243WIN (same as .260 Rem except 6mm vs. 6.5mm neck)
And 6CM w. 110 SMK vs.6.5SLR w. 140 HVLD (both at mag length)