I'm going to wrap this little experiment in the 4th part by looking at some of the outliers, some of the bullet weights not commonly encountered in .30-06 ammo, and as you'll see- some things just make you scratch your head.
We'll start off on the heavy end- The Sumo Wrestler.
220 grains of lead all bundled up and capped with a round nose. I'll say at the beginning that I'm surprised that ammo companies still load this. It's been around since almost the very beginning and today could be regarded as an anachronism- but first, an explanation.
In the ye olde days all cup and core bullets were essentially the same design- thin gilding metal jackets over soft lead cores. These bullets when driven to what we'd consider "normal" velocities would simply explode on impact and a couple things happened. In some parts of the world, hunters just gave up on the expanding bullet idea (Bell, notably) but other folks decided that more lead equalled more dead and simply made the expanding bullets heavier which in itself did a couple of things- the greater mass slowed the bullet's MV which in turn slowed impact velocity to something survivable and the added material made fragments (if they occurred) to be large enough to penetrate well on their own. To folks who'd cut their teeth on a 94 in WCF or one of the blackpowder behemoths- the amount of penetration possible with the '06/220gr RN would have been unbelievable. For that matter, it was considered not inappropriate when Hemmingway knocked a rhino spinning with one.
In the North, it was widely held that you carried some 220s for bear protection or to shoot at a moose up close and you shot 150s or 180s for everything else. Given the relatively immature state of bullet technology back in the day- that advice made a lot of sense, but in today's world of bonded and mono metal bullets it is just an artifact of times gone by. It was also widely held that heavy bullets penetrated brush better, modern testing has proven that pure bull crap, so we won't discuss it further.
Why not just use your 180 grain bonded bullet instead of that lumbering lead beast? Modern controlled expansion bullets will penetrate just as deeply as the old 220gr...without the 100 range penalty the 220gr gives with it's 2400fps muzzle velocity. There is simply no point in it not to. In my test rifle, my dusty old 220gr Corelokts grouped about 5" at 100yds. Hardly stellar and certainly not useful in open country considering it's already 13" low at 300yds with a 200 yard zero. The 220 turns the '06 into a 200 yard gun and if you're worried that much about oversized critters then by all means get a bigger bore rifle. That result isn't unusual- that box of Corelokts is dusty because out of all the '06 rifles I've owned- not one of them shot the heavy stuff that well.
The ability to shoot the heavy for caliber bullets is widely touted as an advantage the '06 has...but I believe that's hardly an advantage any longer in the world of the Barnes TSX and Trophy Bonded Bearclaw. You simply give up too much accuracy and range for the same penetrating power with a modern projectile.
When you go to the other end of the spectrum though- The Flyweights make even less sense.
In the rural South several folks I know pressed the '06 into the varmint rifle role by inserting a 125gr bullet into the chamber. At first glance the 3140fps MV looks impressive...but hold on a second. First of all, I've never had a rifle that would get that much with the 125gr...3050 is about the tops in a 22" barrel. With a 200yd zero, the 125 is shooting exactly 0.8" flatter than a regular old 150gr at 300yds.
Yep, you read that right- 0.8" as in eight tenths of an inch which is simply statistical noise in the great scheme of things. It shoots no flatter than a 150gr load and is only 1.6" flatter than the all purpose 180gr load... at 300 yards. That's basically nothing. I've noted that much variation in the same bullet weight between brands.
In my test rifle the 125 gr shoots decent enough- about the standard 2MOA I've been getting out of everything else but the catch is the pattern is 11" left and 8" higher than the rest of the groups. The thought of re-zeroing the rifle just to use 125gr on varmints or small deer and then rezeroing for 150-180grain ammo for bigger game just makes my head hurt. I suppose the 125 might recoil slightly less than the 150s but it wasn't enough for me to detect in my 7.5lb rifle and certainly not worth the hassle of screwing around with the scope.
Sorry- but that 125gr load is just the answer to a question nobody asked and is pure marketing.
And if that wasn't bad enough the next load is far worse- the famed 55gr Accelerator. I was actually holding on to a partial box of these for some odd reason or another. The ballistic table puts these at a rated MV of over 4000 feet per second or the equivalent of the hot 220 Swift. Why a guy would need to turn his big game rifle into a blistering, saboted .22 is beyond me but it's been in limited production for almost half a century now.
In my test rifle I fired 5 rounds and found 3 .22 cal holes in the 30" target - more or less scattered randomly about. The other two either failed to hit the target or centered into one of the other .30 cal holes (pretty darn unlikely). Bottom line is though- 3/5 on a 30" square at 100 yards is not exactly varmint accuracy. Heck, on good days I've beat that with an iron sighted revolver and it's a cinch with my scoped .22LR...at 100yds! Despite the fact that it shoots theoretically flatter than a 125 or 150gr bullet, it lacks enough accuracy in my rifle (and I suspect most others) to hit varmint sized creatures at much beyond bayonet range.
I also fail to see how a 55gr sabot or a speedy 125gr bullet is somehow more desirable or deadly on a varmint or predator than a 150-180gr conventional big game bullet. I suspect marketing has something strongly to do with it...bottom line the .30 cal is oversized on anything regarded as a varmint or small predator like a coyote, fox, lynx and the like- regardless of the projectile.
The very good and very old .30-06 is more than an acceptable hunting cartridge for many animals around the world. It's most useful bullets weigh between 150 and 180grs and there's almost no difference in trajectory out to practical hunting ranges, so pick the weight your rifle likes best and one that's constructed with your intended quarry in mind- the bigger the animal, the tougher the bullet should be. Bullets that are heavier and lighter than those weights are probably not terribly useful in the field. It's better to choose one bullet weight and type and stick with it for the most part.
To that effect- the '06 is a fine choice for hunting, albeit not a terribly exciting one.
Footnote: After the shooting portion of this test was conducted, the rifle was sold to a friend of mine who wanted it. As good as the rifle was, it simply didn't do anything more (or less) than my current game rifles. I'm certain at some point another '06 will cross my path.