Archive for the 'Ammunition' Category

Found on social, here is the initial question:

I have a question about 45 ACP ammunition.

It appears to me that there are two weight classes of ammo: 230 and 185 grain. Why is this and what’s the correct weight to pick for a self defense and training? I will be shooting using a 5″ barrel 1911.

Thanks for your comments.

The answers were shallow, so the asker rephrased them in a way you might find interesting to discuss:

I think the question I have is two part (1) defensive ballistics and (2) training.

Defensive Ballistics:
Are the heavier or lighter rounds better with regards to hollow point bullets? Do people pick light bullets because they travel faster allowing better expansion? Does this matter, i.e., do both weights expand the same? I kind of like the idea of a heavier round that may impart higher energy to the target. What is the trade off between weight, velocity, energy, and expansion? Because there seem to be either heavy or light bullets, is the decision already clearly made?

Training:
When I purchase my 9mm ammo, I picked an carry round and training round that were identical weight and rated velocity. My assumption was that I would train using the cheaper ammo and carry the expensive ammo, but the feel of the shot would be the same. I was told by someone that carries 1911 that, “I train with 230 grain and carry 185 grain.” This makes no sense to me since I imagine that the two will have very different feel. Am I wrong?

Thanks,

Well, I train with 230 and carry 185, so maybe I’m wrong. I’m interested in feedback as well. Frankly, 230 JHP is expensive and often difficult to find because, I think, police departments are always buying it. His questions are excellent.

I found it somewhat amusing that he couldn’t believe the muzzle velocity data he was getting.  Am I the only one who knew that they would publish the ballistics based on wheel gun muzzle velocities – probably from a 6″ barrel?

But the main takeaway for me, and the reason for posting this, has to do with the degree to which the bullet just disintegrates in tissue.

It’s behavior is similar to what we saw with PatRMG testing the .45-70 LeverEvolution,  Jacket came off, lead shards went everywhere, tissue damage was extensive, and probably meat damage was so severe that it could not be processed and consumed.

If this is the performance of this round, then it’s great for personal defense in the bush.  It penetrates AND expands, causing massive damage.  But it’s no good as a hunting round.

It seems to me a better hunting round would be the monolithic copper bullets which open quickly but stay completely intact.

Source:

I’ve never shot polymer-coated or tipped rounds.

Poly-coated Bullets—polymer coats the entire bullet, creating a number of advantages of shooting or loading by hand. Because they’re coated in polymer, they don’t release as much gas from each round, which helps with indoor shooting. The polymer creates a smooth feed in magazine loaded firearms. And the polymer also reduces residue left in a firearm’s barrel. Sometimes color-coded by use.

[…]

Polymer-Tipped—bullets with a plastic or polymer tip that improves aerodynamic stability for hunting or long-range shooting. Other advantages are associated with the tip being forced back into the body of the bullet and aiding with expansion, as well as a more reliable feed in semi-automatic firearms. The concept is simple enough; it can fly like a Full Metal Jacket bullet, but expand like a hollow point. The ability to injection mold these polymer tips has also aided in manufacturing consistency. Made famous in the Nosler “Ballistic Tip” design, polymer-tipped bullets are now being made by many manufacturers for big-game hunting, long-range competition, varmint control, and now even personal defense ammunition.

Several other types are mentioned in the same short paragraph fashion at the link.

Thanks to @Georgiaboy61 in comments for mentioning Bryon Litz. A simple search found some useful calculators.

Berger Bullets has these Bryan Litz Ballistic Tools, including a  Twist Rate Stability Calculator and this Ballistics Calculator. Included is the Applied Ballistics online Ballistics Calculator, which has more fields providing greater data granularity. Applied Ballistics also offers a desktop Ballistics Analytics Program. We hope you find these tools useful but if readers know of other valuable tools for reloading or shooting, please weigh in.

I thought readers might find some interest in this.

As a bullet is fired, the rifling in the barrel forces the bullet to spin. So, in a 1:8” twist, rate the bullet rotates one full turn every eight inches. In a 1:7” twist, the bullet rotates one turn in seven inches. The smaller the number, the faster the twist; you need to remember this.

[…]

If a bullet spins too slowly, it cannot stabilize and won’t achieve either optimum velocity or accuracy. What occurs is called yaw. The bullet is unstable and does not hit the target with the tip of the bullet, but perhaps the side of the bullet.

I built a retro AR-15 with a 20” barrel and 1:12” twist and fired 77-gr. bullets that perfectly keyholed the target because the rifling couldn’t stabilize the longer, heavier bullet. So, the bullet hit the target sideways. Accuracy is horrible with heavy bullets in that rifle. With 55-gr. bullets, however, that retro rifle with a 1:12 twist shoots the black out of the target. Rifling can also be too fast and over-stabilize the bullet causing the bullet to fragment in flight and lose all effectiveness.

When Eugene Stoner developed the AR-15, the idea was to use lightweight bullets in the 45- to 55-gr. range through a 20” barrel. Barrels were rifled in a slow 1:12” twist rate, capable of stabilizing lightweight bullets but not heavier bullets. Fast forward a few decades, and .223 bullets have evolved in bullet style, bullet material and weight. Today 75- and 77-gr. .223 bullets are just as common as 55- to 62-gr. bullets. Twist rate is your clue on what weight bullets will perform optimally in your gun. Some shooters might not think twice about the twist rate in their barrel, but if they knew that could fine-tune their bullet performance they might pay closer attention.

Twist Rate Sweet Spot

Most AR-15 rifles and carbines produced today use rifling with a 1:8 twist rate. In my opinion, a twist rate of 1:8 is perfect for a general-purpose, 16” barrel AR since this twist offers versatility and can easily stabilize both light and heavy bullets. In fact, the sweet spot for 1:8 bores are bullets weighing from 62 to 77 grains.

In the 1980s, when the U.S. military moved to the M16A2 rifle and the 62-gr. M855 cartridge, it chose a 1:7 twist rate that has become the de facto rifling in all U.S. military rifles and carbines chambered in 5.56 NATO. The change had to do with the 1:7 twist rate stabilizing heavier 70- to 77-gr. bullets and the rifling’s ability to stabilize tracer rounds. The 1:7 twist can stabilize bullets weighing up to 90 grains.

I had an engineering professor who was fond of saying, “Test them like you use them”. So, to prove out the thesis, I sat down at the range bench with a stock, off-the-shelf Springfield Armory ATC with its 1:7 twist rate for heavy bullets and mounted with a Leupold Patrol 6HD 1-6x24mm scope. I used Nosler cartridges since they provide a wide assortment of bullet weights, bullet material and bullet types — from lightweights like the Expansion Tip 55-gr. lead-free ET rounds and the Ballistic Tip 55-gr. BTV, to Match Grade 70-gr. RDF (Reduced Drag Factor), and the lunker in the bunch Match Grade 77-gr. HPBT.

More, including test results, at the link.

All Outdoor.

Ideal twist rates produce a gyroscopic factor between 1.5 and 2.0.

Factors between 1.0 and 1.3 are marginally stable, but they’re generally considered too slow. Factors between 2.1 and 2.9 are fast, but stable and accurate. Factors above 3.0 are suitable, but not ideal. Climbing above 4.0 may cause over-stabilization of the round being fired, which can harm accuracy. The optimal twist rates for 5.56 and .223 loads are:

• 45-gr Varminter: 1:12 twist
• 55-gr (M193): 1:9 twist
• 62-gr (M855): 1:8 twist
• 77-gr (Mk262): 1:8 twist
• 80-gr Sierra Match: 1:7 twist
• 90-gr Sierra Match: 1:7 twist

The way I read the table, 1:9 twist rate is good for just about anything up to 77 grains.  I wouldn’t shoot anything above that in 5.56mm anyway.  Heavier bullets than that need to be .224 Valkyrie, 6mm ARC or 6.5 Grendel.  I once thought that .224 Valkyrie was a flash in the pan, but occasionally I do see it at Academy and Cabella’s.  It’s also possible to pick it up via Ammoseek.

I don’t have anything in that caliber and would not.  I like the 6mm ARC too much to switch to something less effective and versatile.

If you’re shooting hollow point ammunition through the firearm designed for that ammo – including barrel length, shooting at the expected distance, at a target that fits the design purpose of the ammo, and you’re still not getting any expansion, why?

Richard Mann writing at F&S.

• 30-30 Winchester
• 357 Magnum
• 44 Magnum
• 45/70 Government
• 360 Buckhammer

[ … ]

The 30-30 Winchester and the 30/06 Springfield are often considered the two most iconic American rifle cartridges. They’ve withstood the test of time. But they’re not the oldest or the most versatile. The 45/70 was introduced in 1873, 21 years before the 30-30 and 33 years before the 30/06. Originally designed for the Trapdoor Springfield, the 45/70 gained its current fame in the lever-action, and it is arguably the most popular lever-action rifle sold today. By modern standards, original 45/70 ballistics are pathetic. Modern 45/70 loads are not. And when all the 45-70 loads are considered, you have what might be the most adaptable big game cartridge of all time.

There are essentially three power levels of 45/70 ammunition, which is a trait no other centerfire rifle cartridge can claim. Power-level-one loads replicate the cartridge’s original ballistics and launch a 405-grain bullet at about 1300 fps. Inside 75 yards they’ll work for many big game animals. Second-power-level loads are generally loaded with a 300-grain bullet and pushed to about 1800 fps. They can generate more than 2000 foot-pounds of muzzle energy and are sufficient out to around 200 yards for non-dangerous critters. And finally, there are the third-power-level 45/70 loads. These can generate more than 3500 foot-pounds of muzzle energy—with recoil to match—and are sufficient for spy balloons or any beast walking Earth.

He also discusses the other cartridges, including one of my favorites, the .44 magnum.

I always enjoy reading Richard’s work, but my goodness it seems way, way premature to include 360 Buckhammer in that list.  It’s brand new, and in my opinion will end up being a flash in the pan.  Basically it doesn’t really do anything that the 30-30 can’t with the heavier loads (e.g., I have both 150 gr and 170 gr sitting on my desk in front of me now, and ballistically, it’s not really proven that the 170 gr does any better than the 150 gr.).  It’s parent case is the 30-30, just with a heavier bullet.  It’s also not proven that the .35 Remington does any better than the 30-30.  I just don’t think there’s a void to fill with the 360 Buckhammer.  Prove me wrong with ballistics analysis.

But let me tell you where I think there is a void.  Between the .44 magnum and the 45-70.  The perfect cartridge to fill that void is the 454 Casull, and I have written both Henry and Marlin begging them to introduce a rifle chambered in 454 Casull.  Apparently, my protestations have been to no avail at this point.

Anyway, I expect 350 Legend to wane in popularity, and I don’t expect wide availability of the 360 Buckhammer.  It may be an item of interest at some point (“Wow, I haven’t seen one of those in a long time, it may be a collector’s items at this point”), but it remains to be proven.

The 30-30 will never go out of style or off the market, and there will always be a high demand for either a new release by Marlin or a legacy JM stamped 336 in 30-30.

But I demand that Marlin introduce a Model 336 in .454 Casull.  I’ll buy two immediately upon release.  And I’d be happy to write about 20 articles on a new 336 in .454 Casull for Marlin if they send me a prototype.

It’s a deep penetrator and hard hitting round, and causes a significant wound channel.

In case that wasn’t too impressive, watch a slow motion rendering of what happens with this round in ballistic gelatin.

Video here.

This video is interesting for reloaders (and for me too even though I don’t reload).  I suppose an interesting question might be how much deviation from exact concentricity is there in factory ammunition between ordinary bulk supply milstandard cartridges and more expensive hunting rounds?  The immediate question, however, is how much deviation should you aim for if you’re a reloader?

Here is an article in Rifle Shooter Magazine that also bears on the subject.