Home Forums Hunting & Shooting Ask The Gunwriters Sectioned Partitions

Teeder,

Here's an excerpt from the chapter in Gun Gack II about "Killing Power":

"Eventually it occurred to me the diameter of .338 bullets is only 3/100th of an inch larger than .308 bullets, which ain’t much. After experimenting a little with a Starrett digital micrometer, I found that wrapping a .30 caliber bullet in a single layer of stiff business card resulted in a diameter of just about .338 inch.

It also occurred to me that an expanding bullet’s initial diameter isn’t what kills big game. Instead it’s the 'mushroomed' diameter, which punches a much larger hole. So I opened the over-sized tackle box containing my collection of recovered bullets from half a century of big game hunting, and took out all the .30s and .33s.

The bullets included a pretty comprehensive list: Barnes TSX; Hornady Interlock and Interbond; Norma Oryx; Federal Deep Shok; Nosler AccuBond, Ballistic Tip, E-Tip and Partition; Speer Hot-Cor; Swift A-Frame, and Winchester Fail Safe. I measured the width of each bullet’s mushroom at its widest point, then measured the next-greatest width, averaging the two measurements.

Since there’s only .03 inch difference in unexpanded .30 and .33 bullets, I didn’t expect the average difference in expanded bullets to be much larger, and it wasn’t, turning out to be just about exactly .05 inch. But the .30s averaged larger, not the .33s!

This seemed odd, so I looked closer at the results and discovered the reason: Two kinds of .30 caliber bullets expanded very widely, Hornady Interbonds and Norma Oryxes, all averaging over .7 inch across their mushrooms, while none of the others measured over .668.

None of the .33s were Interbonds or Oryxes, so I eliminated those two bullets from the .30 caliber results, then re-averaged the rest. However, this still came out slightly in favor of the .30s, .631 to .620. Obviously, results might be slightly different for other batches of recovered .30 and .33 caliber bullets, but my results indicate there’s no major difference in their expanded mushrooms."

Can also post a later portion of the chapter, about why I (along with some other experienced hunters) think calibers (not cartridges) larger than .338 up tend to kill quicker.

Mule Deer,
Could this average expansion be due to the average .308 cal bullet having a thinner jacket or softer construction than the .33 caliber?

I sincerely doubt it. FAR more hunters use .30-caliber cartridges as all-around big game rounds than use .338 cartridges.

Plus, I found the same thing with "monolithic" bullets--or those that work in the same basic way, such as the Fail Safe. Killed a LOT of big game with them in the 1990s, before Barnes solved the accuracy problems with the original TSX with more consistent copper, and especially the grooved-shank TSX.

Might also mention that in the early 2000s I went on a gun-writer nilgai hunt in South Texas, where 15 hunters got to shoot both a cow and bull nilgai with the then-new .270 WSM and 140-grain Fail Safes--a now discontinued bullet that worked just about like the Barnes TSX.

In case you're not familiar with nilgai, they're about the size of elk, but the bulls have far thicker hide and shoulder bones. For a number of years they were reported to be the hardest-to-kill (and most bullet-resistant) of any game animal in North America. In fact, many Texas outfitters suggested a minimum of .375 Magnums for hunting them.

The year before the hunt I mentioned (which was my second nilgai hunt), a similar group had hunted the same ranch with .300 WSMs with the 180-grain Fail Safe. When we showed up with .270 WSMs, the outfitter and guides thought they'd be chasing around a lot of wounded nilgai--partly due to the mere mention of ".270".

Instead, by the end of the hunt we'd killed 30 nilgai quite handily, perhaps because the shooters on average shot better than those on the .300 WSM hunt (which may or may not have been due to recoil). But the outfitter and guides decided on the basis of that evidence that the .270 WSM was a BETTER nilgai round than the .300 WSM.

Of course, a .30 caliber round should kill big game better than a similar .270 caliber round, especially with a heavier bullet. But that didn't happen.

Which is one reason, among several, that I tend to doubt generalizations about cartridge/caliber/bullet performance on big game.

And also why I tend to doubt generalizations about bullets, especially when I know Nosler (and other bullet companies) tend to tweak bullet construction, even of the same caliber and model.

All very interesting, enjoy this kind of stuff.
I managed to get some failsafes in 270 140 grain I want to try.
also some 140 grain in 7mm I want to try in my 7-08 from an auction.

JB, your last two posts were outstanding. Well shared.

Excellent info MD!

Specifically, how do the 200 PT'S and 210 PT'S compare for expanded diameter?

My assumption is the 200 expands narrower, but drives deeper.

Thanks!

As I've mentioned before in my writings, one of the advantages of being a gun writer is getting to see a LOT of game killed by other people, and not just primarily relying on the animals I've personally taken. I've been able to observe a lot of hunters using a wide variety of cartridges bullets over the decades, at first due to guiding for some years in Montana, along with accompanying Eileen on most of her hunts.

But around 2000 more bullet/ammo companies decided to start actually "field-testing' new bullets and cartridges extensively, partly by inviting gun writers to do considerable hunting/culling in different places. This was about when some South African landowners (and some in Europe, and other countries) realized that instead of paying "cullers" to shoot excess animals, American hunters would actually pay to do the same thing. Consequently I got to go on a LOT of hunts where a LOT of animals were taken--and tried to accompany as many other hunters as possible, and also spent considerable after-hunt time in the skinning shack, where the animals were processed. The biggest was a month-long hunt on RSA where almost 200 animals were taken, from springbok to Cape buffalo. I only personally shot around a dozen animals, but got to personally observe a bunch of other taken--or the results. But went on a bunch of others, such as the 30-nilgai hunt just described.

Also as a result of those hunts, I was able to fiddle with a number of different kinds of "test media," to determine which kinds resulted in similat results to actual hunting of big game. Eventually settled on a couple of kinds of media, one for testing for "softer" broadside chest shots, and one for testing that simulated hitting heavy bone.

But my main point is that a LOT of bullets/cartridges/etc. work on big game, though in different ways--often due to the limits of certain types of bullets. Recently wrote an upcoming article on typical cup-and-core bullets, and realized while looking through my hunting notes that while I've taken a bunch of "deer-sized" game from Montana to South Africa with the 7x57 and the 160-grain Sierra GameKing handloaded to around 2675 fps, ALL have exited. This is because plain old "cup-and-core" bullets have always worked well when started at moderate muzzle velocities, though sometimes not when pushed to 3000+ fps.

There's always something to learn....

I actually don't know how their expanded diameter averages when shot into big game, because have never recovered a 200-grain .30 Partition from any animal, whether it was shot from a .30-06 or various .300 magnums--and have used a bunch of 'em since 1977, when I started using the original lathe-turned "semi-spitzer" or "blunt-nose" model. One did stay inside a Colorado bull elk after a "raking" shot, as Elmer Keith called them, at close to 400 yards--but never found it after tracing the bullet's path through the guts into the chest cavity.

But have never been able to see any difference in how both bullets killed when shooting a number of animals at various ranges.

Good enough for me. 👍

Yeah, I started using the "turned" version if the NPT's in the 270 & 338 in the '70's as well & have stayed with the NPT as a primary bullet in just about all my guns.

I've used a variety of other, newer bullets from various makers, but have never been let down by the NPT in any caliber.

I really don't recall a single (genuine hunting) rifle over all that time that didn't shoot them well enough for all hunting purposes to 500 yards either.

This is the typical performance over a range of animals, close & far, that I've managed to catch..............most exited. These are both 270's with 130 's on the left & a 150 on the right.

YMMV

MM

Without a doubt Partitions are the schitt and they shoot lights out. If you own a rifle that dosen't shoot a Partition well schitt can it.

I agree. I can't think of a rifle that didn't like the partition. Some shoot much better than you could ever imagine.

Great thread!

I probably should do a round 3 follow-up. Pretty sure I have some PT's that weren't cut yet.

Some may find the following both interesting and having some significance: I have two .338-caliber, 250gr Partitions retrieved from a bull moose. From 165 yards the first went through the broadside chest behind the shoulders, sending lung tissue and blood about 20 yards across the bushes. The 1000 - 1100 lb bull staggered but wasn't going anywhere. The 250 Partitiion left the muzzle of my .340 Wby at ~ 3000 fps (many chronographed before the hunt). So impact was around the .338 Win Mags published MV. I sidestepped a few yards for a better angle and the bull saw me for the first time and started to swing away. I gave him another that hit behind the short ribs as he was swinging away and he went down in a depression, out of sight. But I was ready to give another if he got back up, which he didn't until a few minutes later when my son arrived from a blind 350 yards away. He got too close and the bull stood in a very wobbly condition - and wasn't going anywhere. But I'd closed the distance to about 35 yards, and when he stood all I could see was his rump facing me whereupon I gave him another in the rump and he went down to stay. My son saw the bulge of my second shot on the offside about 4 inches from the exit wound from the first shot. He dug it out with a knife. That was the first 250gr retrieved. The 250gr from the third shot into the rump was also found by the butcher in the front part of the chest cavity. Before the carcass was delivered to the butcher 36 hours later (we had to wait until the following day to finish matters before leaving camp, then a 1000 mile drive home, then the following morning the moose was delivered to the butcher). So the moose had been field dressed and cut in two aft the short ribs to fit on out trailer. That bullet, as stated, was found by the butcher in the front portion of the rib cage.

The two bullet retrieved: The second, found under the hide by my son next to the first exit wound = 173 grains (69%)/ .61" avg diameter/ .58" in length. The last shot (3rd) into the rump, found by the butcher in forward part of chest cavity = 175 grains (70%)/ .70" by .62" expansion/ .45" in length, from 35 yards impact velocity was 2900 fps yet it epanded more, penetrated more and was significantly shorter! Of course, impact velocity was about 250 fps faster than the first two shots from 165 yards.

A 286 Partition was retrieved from a black bear shot frontally in the chest. In skinning it was found just poking through the hide in the right flank just in front of the hip. That bear went over an embankment and found dead at the bottom. It's retrieval is another story, but:

The bullet had tumbled with some "wings" on one side pointing forward. Nontheless, it retained 74% of initial weight (211 grains). MV from my 9.3 x 62 (1/14 twist) = +2600 fps. From treestand to bear = 68 yards as it faced me.

Bob
www.bigbores.ca

I'd be all eyes to see that.


Great info. I shot a few elk with the 250 PT's from the 338 Win with a 2780 start speed and never even came close to recovering one of them. 210's whistled thru elk pretty easily as well.

Anybody have sections of (or the ability).257/115gr & .277/130gr Partition? Very curious about their construction similarities - to me they have acted identically on game.

Who was that dude that said "load Partitions, shut up and go hunting " ?

I've only ever caught a single 210gr Partition out of a 338 Win Mag. Exits on deer, elk, bison. But caught one in a doe pronghorn...