Home Forums Hunting & Shooting Ask The Gunwriters How many believe you can make a bullet deadlier by slowing it down?

I recall reading an article (or post here) by "Mule Deer" where he was talking about a .375 magnum. In it, he wrote he might slow down the bullet while reloading, to make it better suited for dangerous game. At least, going by memory - that's what I think he said.

Numerous books I've read about African hunting have told of professional hunters who opined that somewhere around 2200 to 2400 fps was some sort of "sweet spot" for bullets when deep penetration on dangerous game was desired. Downloading some rounds was thought, at least some of the time anyways, to make them more effective.

When I think of the list of cartridges that have long held the reputation of "punching above their weight" I think of cartridges shooting long-for-caliber bullets - at very mild velocities. The 6.5X55 with its 160 grain bullets, the 7X57 with it's 175 grain bullets, the 30-06 with it's 220's, the 9.3X62 with its 286's and the .375 H&H with its sometimes downloaded 300 grain bullets, come to mind.

In "bullet theory" we seem to have two different camps of subscribers. One group - call them the "kinetic energy" crowd, feel that the more energy you put behind a bullet - the deadlier you will make it it. The second group - call them the "moderate velocity" group, feel that slower bullets will generally make deeper, more and consistent wound channels.

According to the "bullet theory" I've read about, and tested myself, it seems that the faster one drives a bullet - the more violent the expansion, which usually anyways, seems to result in a larger around, but shallower hole in the animal or test media. The slower bullets seem to expand in a more gradual fashion, and as a result, often penetrate deeper.

So, in the fashion of a good old fashioned campfire debate, I'd like to pose the following questions for every one's debate and discussion.

"Can slowing a bullet down make it a more effective killer of game?" Give the reasons for the thought behind your answer.

My second question would be:

"Is there a "sweet spot" when it comes to impact velocity in regards to killing power?"

Thirdly:

In regards to the newer homogeneous bullet designs (which may well alter the "traditional" rules), "Does driving an all-copper bullet faster always make it more effective?"

Thanks gentlemen.

No, No, maybe..

I guess I do, as long as it is being slowed down by a front shoulder or two...

Dober

I don't believe there is a magic velocity. The reason "slow" rounds of the past may have penetrated deeper is because at high velocity bullets may have fragmented & lost weight or expanded to a much smaller frontal diameter. A bullet that is designed to stay together will penetrate deeper the faster it goes so long as there is something to limit it from expanding to a very wide diameter. Basically some bullets may work better at lower velocity (and hence kill better), but that is a bullet design issue. I believe, so long as bullets can handle it, the main reason DG rifles are generally in the 22-2400 fps range is because at higher velocity already severe recoil gets extraordinary. Whether increase in velocity increases killing power signficantly everything else being equal is debatable, but it certainly will not decrease it.

Lou

I think there is a "sweet spot" for a quick kill and minimum tissue damage (bloodshot meat). With current bullet design, I think the "sweet spot" has been opened up to a "sweet range" for ethical kill. I shoot what is tolerable in terms of recoil (I have an aversion to those cartridges pushing 15lbs or more back at me) so I'm automatically in the moderate group, but not the bigger is better crowd. To me a 7mm bullet moving around 2700 to 3000 fps does what I need with a minimum of fuss. Ain't much around here that it won't work on. I wouldn't try it with anything that bit back.

I second Lou270. It is just what I was going to say.

If a bullet is holds together (non-expanding and not deformed), faster means more penetration for the same diameter bullet; once it enters and encounters resistance, it will slow to the 2200-2400 fps range.

Of course, recoil will steeply enter the picture at the higher velocity.

I think 'the slowing down' depends on the bullet in question. If 3000 fps causes a bullet to shed its jacket faster than a prom dress but 2800 causes a perfect mushroom (not over-expansion) that blows through both shoulders. I'll take the pass thru everytime. But to answer your question...it's a definite maybe. Just b/c I like a pass-thru doesn't mean that IT is more deadly, just insurance in a blood trail.
Lots of smoke surrounding this question...the whole 'deadlier' thing is hard to nail down. How do you prove 'deadlier'?

The answer is, it depends.

Gary Sciuschetti did a laborious bit of research on 30 caliber bullets, impacting wet telephone books at various speeds. The study took samples of many different brands of bullets. The output measurements were percent weight retention, and inches of penetration.

Gary presented his number in tabular form, along with photos of the recovered bullets. He fired three bullets for each speed-type combination.

I have posted some of the results in graph form here a few times, and have attached it again.

For standard bullets, the shape of the curve is not at all what you would expect. The slope is downward to the right, i.e., shorter wound channels as impact speed increases. The shape of the curve is also interesting. On the far left (low speed), there is a portion of the curve that is steeply downward. Then the curve is almost level for a while. Finally, there is another steeply downward portion of the curve.

My interpretation of this is that below 2100 FPS, the bullet does not open, or does not open much. The result is a long, thin wound channel. When impact speed is above 2100FPS, the bullet opens, forming a larger, nearly constant length wound channel. The channel length is surprisingly constant at 14". When the impact speed reaches 2800 FPS, the curve begins a very steep downward portion again.

Short version: Below 2100, very long skinny wound channel, 2100-2800 a 14-15" long large channel, and above 2800 a much shorter wound channel.

If you use Partitions, then the "corners" of the curve are 1700 FPS and faster than heck. The effect of a Partition is to give you a much larger range of effective impact speeds. Also, penetration increases by about 2-3 inches, vs. standard bullets.

So, yes, under certain circumstances, slowing the bullet down improves penetration. Rocky is fond of saying that there is absolutely nothing wrong with a 2500 FPS muzzle velocity, and he's right.

A complicating factor is that wet phone books are quite a uniform medium, and animals are not. Gary took care to validate that mean penetration in phone books is about the same as mean penetration in deer. However, in deer, the data are much less uniform because bullets do strike large bones.

Unfortunately, I did not include data below 2100 FPS on my graph. I guess you'll have to either trust me, or look up Gary's chart.

Garry Sciuchetti's 30 caliber 180 grain bullet test report is attached to this post. It is a must-read for any rifle loonie, and the "Holy Grail" of 30/180 bullet performance. For a pleasant surprise, be sure to look at the performance of the plain old Remington SPCL (round nose) bullet all through the range of test velocities.

The 2200-2400 fps sweet spot mentioned is actually a compromise. On one hand, velocity and "shock" aid in terminal performance. On the other hand, optimum penetration is achieved beginning at about 1600 fps, and begins to degrade above about 1800 fps due to hydrostatic forces. Some believe 2200-2400 fps to be the ultimate compromise in terms of terminal effect.

No single set of numbers apply to the performance of all bullets at all velocities. But I can tell you for certain that every bullet made has a velocity window within which that particular bullet performs best. Given that fact, there are instances where slowing a bullet down to within it's optimum window actually does improve it's performance.

-

Shot an itty-bitty Texas deer with a .30-06 at about 25 yards with Federal 150 grains in 1986. Bullet literally exploded on a rib bone and created a crater that was nearly the size of a cereal bowl. Deer died from shredded lungs caused by bone and bullet fragments!!! No exit. Shot another, somewhat larger deer with the same load at 100 yards. Broke the shoulder going in and exited easily, breaking through the off shoulder going out. The only reason had to be the bullet had slowed down a bit at 100 yards and had fallen into the performance zone expected of that round.

Dan

If the bullet is traveling too fast for the design of the bullet, you most certainly can increase the lethality of a bullet by slowing it down. For deep penetration on dangerous game, the 2200-2400fps zone exists because that�s a velocity range that consistently stabilizes a bullet so that on impact it penetrates in a straight line. When you go faster you can encounter some bullet deformity (with some bullets) at higher velocity, which can lead to a bullet traveling in an unpredictable trajectory after impact. So that�s how a slower bullet can actually prove to be more deadly.

For non-dangerous game and medium bores, it all comes down to finding the velocity range the bullet was designed to perform within.

In Denton's graphy, the uptick at the higher velocity "X" is also interesting; it shows the point where the petals are shed.

But, to answer the question, no, I believe in stout (copper) bullets, where faster is better. FWIW, Dutch.

The guys who opined that it is absolutely related to bullet construction are right on. Standard cup-core bullets do in fact have a "sweet range" that runs from about 2400 to 2800 fps. It is no coincidence whatever that standard rifle rounds are designed to launch those bullets at those precise speeds. Bullet and cartridge were designed for each other. (Deuced clever these engineers, eh what?)

In the All-American zeal for bigger and better, we have outstripped that style of bullet by crafting cartridges the size of oil barrels and burning powder weighed out by the ounce. Bullets that vaporize on a blade of grass ten yards from the muzzle are the inevitable result. Premium bullets with armorplate for jackets fixes that, but at the expense of "iffy" expansion when the velocity finally does creep down - somewhere in the next zip code. Bullets CAN be made that stay together up close and yet expand and penetrate out yonder, but at the expense of...well, expense. A buck a bullet isn't uncommon anymore.

For those who are beyond their magnosterone years, who see the value of moderation in all things, and who believe that "magnum" should be reserved for outsize bottles of the bubbly, there IS magic in the numbers 2400 and 2800.

All of which is to say: I'm a Mod Vel guy.

"So, yes, under certain circumstances, slowing the bullet down improves penetration. Rocky is fond of saying that there is absolutely nothing wrong with a 2500 FPS muzzle velocity, and he's right."

There may be more truth to this than meets the eye. One of my rifles, a Ruger 77 RSI in .308 Win. is a one trick pony for sure. The only load it will shoot well at all is the 165 gr. Speer Hot-core. Chronographed MV is 2550 FPS from it's 18.5" barrel. I've dropped deer witht hat load at ranges from about 35 feet to 250 yards, all one shot kills. The only bullet I have recovered came from the 250 yard deer. The deer was facing me and the bullet hit him in the chest and came to a stop against a back leg with enough force to break the leg. Bullet retained about 65 percent of it's original weight with a perfect mushroom. All the other deer were shot at generally broadside and the bullets passed completely though the deer. Most dropped on the spot including the 250 yard deer. The most any deer moved after being shot was maybe 30 feet, give or take.
I forget which, but there was an article by the late Finn Aagaard on using heavy bullets on deer where he used IIRC, 220 gr. bullets in the 30-06 and I believe 175 gr. bullets in a 7x57. i'll have to try and see if I can dig that one up as re-read it.
Paul B.

Dutch, if you'd shoot copper solids, at least .45 cal, you wouldn't have to worry about shedding petals!

Speed kills, no doubt about it. You just have to have a bullet that's up to the task, exhibit expansion and penetration. I've shot enough animals with a 30062700 fps and with a 300 Weatherby@ 3250 to say there is a DRAMATIC increase in killing power. Bullets used were the 180grNP and the Hornady Interlock on both rifles. jorge

The article Brian is referring to is one where I actually mentioned several "perfect" muzzle velocities. The .375 idea is one of Kevin Robertson's (the PH who wrote THE PERFECT SHOT). He loads down 300-grain bullets in the .375 quite a bit, finding they kill just well, but even solids won't usually exit a Cape buffalo, thus preventing accidents when shooting in herds. He also believes (like a lot of PH's) that 2400 is the maximum best velocity for solids, and even many big expanding bullets, because they tend to hold a straighter course when striking buffalo bones than when driven at higher velocities. Plus, many of his clients (especially the less experienced) shoot better when the velocity is dropped to 2400.

One of the other "perfect" muzzle velocities I mentioned was 2700-2800, because typical cup-and-core "deer" bullets pretty much xpand perfectly when driven at that speed--and yet a spitzer will still expand out to 400 yards.

Somebody mentioned that a "controlled-expansion" bullet will penetrate deeper when driven faster. This is true ONLY as long as it retains the same shape, no matter the impact velocity. In reality there are darn few bullets that do this. The Barnes X and similar bullets will do it as long as the petals don't come off (when they normally penetrate deeper). The Nosler Partition normally drives deeper at higher velocities, as does the North Fork and Trophy Bonded Bear Claw.

But there are some that open up wider at higher impact velocities. This has a major effect on how deeply they penetrate, exactly how much depending on the bullet. In general these include bonded bullets without any sort of "stop" on expansion, including the Hornady Interbond, Kodiak, Norma Oryx Swift Scirocco, and Woodleigh.

And some bullets can also be slowed because the REAR end of the bullet expands signficantly on impact. Examples would be the Swift A-Frame and Winchester XP3. On very rare occasions I have also seen the rear of a Nosler Partition bulge a little, but not nearly as much as the rear end of an A-Frame of XP3.

So then, the best way to increase the effectiveness of factory loads is to increase the range at which the game is hit. <nudge, nudge - wink, wink> Maybe my ole 303 Brit IS a 500 yard moose gun after all.

Agree with Rocky on the premium bullets at higher speeds. I used to load 180 Interlocks at 2800 in my '06. They worked like magic. I switched to the 300 Winnie (notice I left the word 'magnum' out ) and was getting 3140 fps. They came apart at the higher velocity. Went to the Barnes TSX, and voila! Great performance again, but like Rocky said -- at an expense -- very expensive in Canada.

I'm hoping to perforate a moose with my 405 Winchester (NON magnum) this fall coming using 300 gr Barnes XFB going about 2400 fps. They sure are accurate!

I love Fadala's article on the broad meplat and .45-70 in Africa in G&A. Bullets launched at 1500fps are driven deeper into dangerous game than lighter bullets fired at faster velocities. Slide rules be damned! Speed may kill, but slow and heavy kills just as well, and probably in many cases more reliably.

Dan

The pictures above are of a 400 grain 416 Rigby bullet at a muzzle velocity of 2370 FPS recovered from a Bison. The shot was a rib cage shot and only a rib bone one the entry and offside was hit