I was messing around on the JBM Ballistic calculator because I am looking for another .270 - .30 caliber barrel for my Ultra (.243 Bull Thumbhole Varmint) and had an opportunity to pick-up a .280 Rem barrel...
I tried an apples to apples comparison of four calibers available from H&R using the same factory available loads (Hornady SST Superformance, bullet weight varies slightly)(other loads may net difference results???)... The four calibers were .270 Win, .280 Rem, .308 Win and .30/06 Springfield... (not considering .35 Whelen, .45/70 etc... as they are in a different category, and not what I am looking for and 7mm/08 comes up a little short of these... not taking away anything from these calibers, just not what I'm looking for).
The standard parameters calculated were in relation to MPBR; (all with a +1.5" sight above bore; Kill zone radius of 4" not the standard 5"... in the deer's lungs from zero to MPBR);
Calibers in Order of performance;
1. .270 Win (140 gr SST... MPBR Zero @ 289 yd, MPBR @ 340 yd, MPBR energy 1819.5 ft/lb)
2. .280 Rem (139 gr SST... MPBR Zero @ 288 yd, MPBR @ 339 yd, MPBR energy 1792.2 ft/lb)
3. .30/06 Springfield (150 gr SST... MPBR Zero @ 283 yd, MPBR @ 332 yd, MPBR energy 1777.3 ft/lb)
4. .308 Win (150 gr SST... MPBR Zero @ 276 yd, MPBR @ 324 yd, MPBR energy 1701.2 ft/lb)
As you can see the differences are very minimal... the higher BC of the .270/.280 seems to account for their collective edge over the venerable .308/.30/06... but since they all group within a small tolerance range, it would appear to be best to decide which caliber to go with based on other factors... versatility, ammo availability, available barrel contours (I prefer bull barrels)commercial ammo cost effectiveness, history/personal preferences (not considering reloading factors, strictly based on commercially available ammunition)etc...
After considering my own applications based on assessing all of the other factors, here is MY own order of preference, for an additional H&R barrel;
1. .270 Win (+ most efficient caliber, + best trajectory and energy retention, + good range of ammo, - only sporter contour)
2. .308 Win (+ bull barrel available, + versatile, + widest ammo option range)
3. .30/06 Springfield (+ versatile, + lots of ammo options, - only sporter barrel available)
4. .280 Rem (- far less range of ammo, - increased ammo cost, - only sporter contour)
Any thoughts or options/factors that I haven't considered???