Archive for the 'Ammunition' Category

Older video but interesting.

Outdoor Life has a great article on various sorts  and bullet weights and types of 5.56 ammo.  I won’t lift a lot of prose out of the article, and you’re recommended to read his view of .223 and 5.56mm interchangeability.  The summary list of ammo follows.

• Best Overall: Black Hills Ammo 5.56mm NATO MK 262 MOD 1-C
• Best Value: Freedom Munitions .223 69-grain HPBT Match
• Most Accurate: Nosler Match Grade .223 77-grain Custom Competition BTHP
• Best for Larpers: Lake City 5.56mm NATO M855 Ball, 62-grain Green Tip
• Best for Varmints: Freedom Munitions .223 55-grain V-Max
• Best for Deer: Remington Premier .223 55-grain Accutip
• Best Lead-Free Ammo: Nosler .223 55-grain Expansion Tip
• Best Ball Ammo: Winchester USA Target .223 55-grain FMJ
• Best for Shooting Steel: Freedom Munitions .223 42-grain Zinc-core FMJ

Match Ammo

• Black Hills Ammo .223 69-grain Sierra Matchking
• Remington Premier Match .223 77-grain Sierra Matchking
• Remington Premier Match .223 69-grain Sierra Matchking
• Federal Gold Medal Match .223 69-grain Sierra Matchking 
• Hornady .223 75-grain BTHP Match
• Winchester Match .223 69-grain Sierra Matchking

Hunting and Defensive Ammo

• Black Hills Ammo .223 62-grain Barnes TSX
• Hornady Black 5.56mm NATO 75-grain Interlock
• Nosler .223 55-grain Ballistic Tip Varmint
• Winchester Varmint X .223 40-grain Polymer Tip
• Hornady Critical Defense .223 73-grain FTX

I don’t necessarily agree with everything on the list (e.g., I find Winchester ammunition to be quite dirty).  I would also add to the list (e.g., I find PMC ammunition to be relatively inexpensive and good range ammo, and it’s not on the list).

However, this is shooter’s choice.  If you have a favorite for some purpose, drop a comment including a URL.

Richard Mann Field & Stream.

He doesn’t like the 6mm Remington because it does nothing for him that the .243 doesn’t.

As for the 6.8 SPC, it’s luster has faded according to him.  Delightfully, he does mention both the 6.5 Grendel and the 6mm ARC.  As you know, I’ve hunted hogs with the 6mm ARC and have wondered why it hasn’t been more widely accepted as a replacement for the 5.56 given it’s heavier bullet weight (> 100 grains), almost equivalent muzzle velocity and almost equivalent recoil.  Made by Hornady for U.S. SOC for high ballistic coefficient and heavy hits at distance, I wouldn’t hesitate to hunt white tail with it.

300 Blackout.  Too weak.  Need anyone say more?

444 Marlin – why use it when you have the 45-70?  I don’t know about that one.

30-06 – his reasons sound to me like personal problems.  Maybe he should get over them.  I know guys who hunt with 300 Win Mag because “I don’t chase a blood trail.”

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?