Christmas Day is just 13 days away. We know many of our readers and Forum members will be traveling to spend the holidays with friends and families. If you will be transporting any firearms when traveling by air over the holidays you need to know the rules.
If you will be flying with firearms this holiday season, you should read this article. You need to familiarize yourself with current Federal Regulations on gun transport before you get anywhere near an airport. Thankfully, the Transportation Security Administration (TSA) has a web page that states the important requirements for airline passengers traveling with firearms and/or ammunition.
You’ll want to visit the TSA Firearms and Ammunition webpage, and read it start to finish. In addition, before your trip, you should check the regulations of the airline(s) with which you will fly. Some airlines have special requirements, such as weight restrictions.
Here are the TSA’s key guidelines for travel with firearms:
TSA FIREARM Guidelines
1. When traveling, comply with the laws concerning possession of firearms as they vary by local, state and international governments.
2. If you are traveling internationally with a firearm in checked baggage, please check the U.S. Customs and Border Protection website for information and requirements prior to travel.
3. Declare each firearm each time you present it for transport as checked baggage. Ask your airline about limitations or fees that may apply.
4. Firearms must be unloaded and locked in a hard-sided container and transported as checked baggage only. As defined by 49 CFR 1540.5, a loaded firearm has a live round of ammunition, or any component thereof, in the chamber or cylinder or in a magazine inserted in the firearm. Only the passenger should retain the key or combination to the lock unless TSA personnel request the key to open the firearm container to ensure compliance with TSA regulations. You may use any brand or type of lock to secure your firearm case, including TSA-recognized locks.
5. Bringing an unloaded firearm with accessible ammunition to the security checkpoint carries the same civil penalty/fine as bringing a loaded firearm to the checkpoint. You may find information on civil penalties at the Civil Enforcement page.
6. Firearm parts, including magazines, clips, bolts and firing pins, are prohibited in carry-on baggage, but may be transported in checked baggage.
7. Replica firearms, including firearm replicas that are toys, may be transported in checked baggage only.
8. Rifle scopes are permitted in carry-on and checked baggage.
TSA Ammunition Guidelines
1. Ammunition is prohibited in carry-on baggage, but may be transported in checked baggage.
2. Firearm magazines and ammunition clips, whether loaded or empty, must be securely boxed or included within a hard-sided case containing an unloaded firearm. Read the requirements governing the transport of ammunition in checked baggage as defined by 49 CFR 175.10 (a)(8).
3. Small arms ammunition (up to .75 caliber and shotgun shells of any gauge) must be packaged in a fiber (such as cardboard), wood, plastic, or metal box specifically designed to carry ammunition and declared to your airline.
4. Ammunition may be transported in the same hard-sided, locked case as a firearm if it has been packed as described above. You cannot use firearm magazines or clips for packing ammunition unless they completely enclose the ammunition. Firearm magazines and ammunition clips, whether loaded or empty, must be boxed or included within a hard-sided, locked case.
5. Please check with your airline for quantity limits for ammunition.
More Airline Travel Tips from Tom McHale
A while back, Tom McHale wrote an excellent article for the Beretta Blog, entitled Ten Things You Need to Know about Flying with Guns. Here are two of Tom McHale’s Travel Tips from that article:
Weigh your gun case and ammunition
Most airlines will allow up to 11 pounds of ammunition. And, like any luggage, you will be charged more for any baggage weighing more than 50 pounds. This sounds like a lot, but when traveling to the Crimson Trace Midnight 3 Gun competition last year, my case with shotgun, rifle, pistol and ammunition tipped the scale past the 50 pound mark.
Pack ammo in the same locking case
This is another area that’s misunderstood and full of internet myth. Your ammo just needs to be stored in some type of safe container and not loose. Technically, you can keep ammunition in magazines, but I wouldn’t recommend it. It meets the letter of the law storage requirement, but too many airline and TSA agents will give you grief. Use a plastic ammo box or original cardboard packaging and you’ll be fine carrying that in the same lockable case as your gun.
*Please see, United States Code, Title 18, Part 1, Chapter 44 for information about firearm definitions.
Who hasn’t dreamed of having a professional-quality, permanent shooting bench on their own property? Well here’s an article that can help you make that dream come true. This “how-to” feature from the archives of RifleShooter Magazine shows how to build a quality concrete shooting bench step-by-step.
All aspects of the construction process are illustrated and explained. The author, Keith Wood explains: “Construction happened in three phases — first creating the slab foundation, then the support pillars (legs), and finally the table.”
Click image below to load article with slide show.
Each step in the process is illustrated with a large photo and descriptive paragraph. Starting with framing the foundation (Step 1), the article illustrates and explains the 15 Steps that produce the finished, all-concrete bench (see top photo).
Yep, it’s wintertime — Christmas is just two weeks away. There is plenty of snow on the ground in many parts of the country. 2025 has brought unusually cold weather to many regions with more snow on its way this weekend. In the Northeastern region, snow storms (with very low temps) are predicted for December 12-15, 2025.
If you plan to go shooting or hunting in the weeks ahead, while the weather is below freezing and snow is on the ground, you need to be prepared. You should always have the right equipment and make sure that you can contact help if something goes wrong (such as not being able to start your vehicle).
The folks at the Precision Rifle Network have created a good video on winter shooting and hunting. Host Marcus Hom provides his TOP 10 TIPS for wintertime shooting/hunting adventures. We recommend that any 4-season shooter watch this video.
TOP 10 TIPS for Winter Shooting and Hunting:
1. Wear Good Sunglasses — With snow on the ground, wearing sunglasses is a must because of the extra reflected light. You can get good sunglasses that also have ANSI Z87.1-approved impact protection.
2. Wear Protective, Moisture-Proof Clothing — Wear a set of Bibs and a long jacket. This will prevent you from getting snow inside your clothing when shooting prone.
3. Take Care of Your Hands — Bring good winter gloves, preferably with a waterproof outer layer. Make sure the inner gloves can work with your trigger/trigger guard.
4. Bring a Good Tripod — A tripod keeps you elevated so you can avoid laying down in snow or slush. That, in turn, avoids body heat loss. “Keeping out of the snow and shooting from an elevated position is pretty important in the wintertime.”
5. Protect Optics and Action — Keep your scope lenses and action clear of moisture, snow, and fog. You will want to have good caps on both lenses. Make sure the action remains closed, and consider some kind of wrap over the action until you’re ready to load and shoot.
6. Ranging Challenges — Laser range-finders don’t perform optimally with intense, bright, ambient light. Also, if it’s showing you may get false readings from snow particles. So take multiple readings to ensure you have the right distance. Also, if you have a reticle with MOA or MIL marks, and you know the size of your target, then you can range the target with the scope.
7. Drop and Windage Info (DOPE) Chart — Bring a waterproof, hard copy dope chart. Out in the field on cold days, a phone battery dies fast, and you’ll want to preserve that battery for emergency phone use if needed. So, you should keep a good old-fashioned drop chart in a waterproof laminate.
8. Muzzle Velocity Issues — Cold temperatures can lower muzzle velocity. Before you go, get an idea of how your velocity will change with low temperatures. Some powders are more sensitive to temperature than others, causing a noticeable reduction in muzzle velocity. A load you’ve worked out in summer may shoot LOW in winter because the actual velocity is low. Even with a “temperature stable” powder you may see a 10 fps slow-down. Do some winter velocity testing if you can before you go.
9. Keep Your Ammo Warm — A simple way to avoid muzzle velocity changes with low ambient temperatures is to keep you ammunition ON YOUR BODY. Have a pouch under your layered clothing where the ammo can be kept relatively warm. See video: 07:50
10. Safeguard Keys and Valuables — Keep keys and valuables in a secure, zippered pocket. “There is nothing worse than losing something… keys, phone, wallet. It’s really hard to find something when its buried under [many] inches of snow”. We also recommend keeping a spare vehicle key hidden on your car/truck. There are magnetic holders that can keep that spare key secure but safely hidden from view.
“Science tells us that exposure to continuous noise of 85 dB for eight hours is enough to cause permanent hearing loss, and worse, spikes of 130 dB and more can result in permanent hearing damage instantly.” Source: NRA Blog.
The Risk of Hearing Loss
Hearing loss can be progressive and irreversible. If you are a shooter, this is serious business. As the NRA Blog cautions: “You may not even realize you’re harming your hearing. Hearing loss occurs gradually, and can go effectively unnoticed until symptoms become severe. By then, the damage is done.”Effective hearing protection is a must whenever you are shooting firearms or when you are in the vicinity of gun-shots. For ultimate protection, we recommend a good set of tapered foam earplugs, topped by ear-muffs. However, there are situations when you may prefer lighter-weight hearing protection that can be quickly removed. For example, if you are standing well behind the firing line as an observer, or if you are working as a rangemaster or waddie some distance away from the shooters.”
Sound Levels for Common Noises:
9mm Luger pistol: 160 dB
Jet aircraft engine (near): 140 dB
.22 LR pistol: 134 dB
Normal human pain threshold: 120 dB
Noisy Nightclub: 110 db
Riding Motorcycle at 65 mph: 103 db
Power Lawnmower: 95 dB
Hearing damage possible: 85 dB (sustained for 8+ hours)
Ringing Telephone: 80 dB
Normal conversation: 60 dB
What about suppressors? If you use a suppressor is it OK to dispense with hearing protection? Not really. Even the most effective suppressors, on the smallest and quietest calibers (.22 LR), reduce the peak sound level of a gunshot to between 110 to 120 dB. To put that in perspective, according to the National Institute for Occupational Safety and Health (NIOSH), that is as loud as a jackhammer (110 dB) or an ambulance siren (120 dB). For normal caliber handguns and rifles, suppressed sound levels routinely exceed 130 dB, just shy of OSHA’s “hearing safe” threshold of 140 dB. Accordingly, we recommend use of hearing protection even when shooting suppressed.
1. Ear Muffs — Max Protection and Compact Options
The highest current USA Noise Reduction Rating is 34 dB NRR. To get that kind of protection, you need pretty big muffs, but thankfully, you don’t have to spend big bucks. For under $15.00 you can buy quality ANSI-approved muffs with a 30+ dB Noise Reduction Rating. Chose the big 34 NRR G&F Pro Muffs at $15.99 or the more comfortable 30 NRR Walker EXT Range Muffs for $14.97. Both products have padded head-bands which retract.
Many hunters and competitive shooters prefer low-profile ear muffs. As these typically have a lower Noise Reduction Rating, perhaps NRR 22-24, we recommend running earplugs under muffs, particularly when you are at a busy range or shooting a match. If you use low-profile electronic muffs, such as Howard Leight Impact Sport Muffs, you should still be able to hear range commands even with plugs underneath.
If you need to talk to your shooting buddies or hear range commands during matches, there are a variety of good electronic muffs on the market. Some of these even have “Walkie-Talkie” functionality so you can talk to team-mates or coaches at matches. We like these 2-way electronic muffs, but be aware that they offer much less max noise protection — typically in the NRR 20-22 range. Here is a good deal currently at MidwayUSA for Walker Electronic Muffs with Walkie-Talkie functionality. This NRR 20-rated unit has slim pads with removable microphone unit. It is now on sale at a 55% discount.
2. Foam Earplugs — Small, Inexpensive, But VERY Effective
Quality foam earplugs offer great hearing protection at low cost. These Howard Leight NRR33 Max plugs are your Editor’s favorite foam earplugs. Between shooting, motorcycling and mowing lawns, I probably have Max plugs in my ears 3-4 days a week. These Leight Max plugs are very effective, easy to insert/remove (with the flared ends), and they seem to be less abrasive in the ear canal than some other brands. Right now you can get 20 pairs of these NRR33 Leight Max plugs for just $8.41.
If you prefer thin, light-weight earmuffs, we do recommend running earplugs underneath for double protection while shooting firearms (or when you’re on the firing line). Sound experts tell us that running plugs and muffs together can improve your effective noise reduction by 4-7 dB NRR.
Howard Leight MAX NRR 33 Earplugs, Just $8.41 for 20 Pairs
Hearing bands are inexpensive, lightweight, and are handy for special situations, such using hedgetrimmers and noisy power tools, when you may need to frequently remove the protection. These banded products are a also a very good form of hearing protection for hunters. You can keep them handy around the neck while spotting game, and then insert the plugs before shooting. We have tried two types of banded hearing protection, the Howard Leight QB2 Quiet Band (shown above) (25 dB NRR), and the Radians Rad-Band (23 dB NRR). The Leight Quiet Band is quite durable and the plugs can be replaced. It is a bargain at just $5.44 from MDI Safety.
Radians Rad-Band is very light-weight, with Jelli™ Plugs that are comfortable, washable, and reusable — all for just $12.13 on Amazon. Peltor also offers Sport Banded Earplugs. These conveniently ship with 3 pairs of ear buds, all for $11.99 on Amazon.
4. Electronic Plugs — New Technology with Adjustable Volume
For maximum hearing protection we still recommend good muffs over quality foam ear plugs, there is a new option available. A variety of companies now offer electronic ear buds that include small speakers so you can hear range commands and conversations. Please note — these MUST be specially-designed protective in-ear devices. Do NOT just use ear-buds designed for music playback!
Howard Leight recently introduced new Impact Sport In-Ear plugs with an impressive 29 dB Noise Reduction Rating (NRR). That NRR is better than most compact ear muffs. The plugs automatically compress amplification when loud impulse sounds (like gunshots) exceed 85dB. Internal amplification allows you to hear range commands and conversations. The cord connecting the plugs includes twin, handy volume controls. These plugs come with moldable earhooks with 3 different ear tip sizes. The deluxe model with quick-connect BlueTooth is available for $89.98 on Amazon. With this high-tech BlueTooth version you can take phone calls.
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Here’s a tip we feature every year or so, because it is something that costs nothing, yet can be very useful in the reloading process.
With a simple, easy modification to a fired case, you can determine the length to lands in your rifle barrel. As long as you set the tension right, the measurements should be repeatable, and you’ve just saved yourself $47.40 — the combined cost of a Hornady commercial OAL gauge ($41.41) and Modified Case ($5.99).
To achieve best accuracy with a rifle, you must control bullet seating depth very precisely, so all bullets end up in the same place relative to the entrance of the lands, every time. There may be multiple cartridge OALs which prove accurate. However, with each, you first need to determine a “zero” point — a reliable, and repeatable OAL where the bullet is “just touching” the lands.
There are tools, such as the Hornady (formerly Stoney Point) OAL Gauge, that will help you find a seating OAL just touching the lands. However, the tool requires that you use a special modified case for each cartridge you shoot. And, while we find that the Hornady OAL Gauge is repeatable, it does take some practice to get in right.
Make Your Own Length-to-Lands Gauge with a Dremel
Here’s an inexpensive alternative to the Hornady OAL tool — a slotted case. Forum member Andris Silins explains how to create a slotted case to measure length to the lands in your rifle:
“Here’s what I did to find length to lands for seating my bullets. I made four cuts into the neck of fire-formed brass. Then I pressed the bullet in lightly and chambered the entire gauge. As the cartridge chambers, the bullet slides back into the case to give you length to lands. It took less than five minutes to get it cut and working. A little light oil in the barrel just past the chamber helps ensure the bullet does not get stuck in the lands. It works great and is very accurate.
How to Adjust Tension — Length and Number of Neck Cuts
I made the cuts using a Dremel with a cut-off wheel. You can adjust tension two ways. First, you can make the cuts longer or shorter. Longer cuts = less tension. If you used only three cuts instead of four you would get more tension. The trick is to be gentle when you open and close the bolt. If you ram the bolt closed you may wedge the bullet into the lands. When you open the bolt it helps to keep a finger or two near by to guide the case out straight because the ejector wants to push it sideways.”
For many years, the U.S. Army Marksmanship Unit (USAMU) regularly published reloading “how-to” articles on the USAMU Facebook page. In this article, the USAMU’s reloading gurus address a question frequently asked by prospective handloaders: “Should I buy a single-stage press, or a progressive?” The USAMU says the best answer is Solomon-esque in both its wisdom and simplicity: “Get BOTH!” However, there is definitely more to the issue, as the USAMU explains below.
Progressive Press Safety Considerations
by USAMU Staff
Many are the beginning handloaders who have asked a friend about their “setting up” a progressive press for them. The idea is that the newbie could then just feed in components and crank out buckets of practice ammo without needing to really learn much about handloading. Tempting though this might be, that’s simply not how it works. Such an approach might be ok if there were never a malfunction with either press or operator, but that’s unrealistic. Our hypothetical newbie would then lack the knowledge to problem-solve most situations.
Worse yet, several different handloading operations would be occurring at different stations on the progressive press at the same time. It takes an experienced operator to keep track of, and truly understand the significance of, all those potential mini-problems. Loading without this experience is a recipe for potential disaster – such as a double powder charge (especially with pistol cartridges) dropped while the loader was attending to some other function, etc. Progressives are an animal unto themselves, and while they offer many benefits, they do take some getting used to – even by experienced handloaders!
ILLUSTRATIVE HORROR STORY
Here, enter a 40-year veteran handloader who decided to jump onto the progressive bandwagon late in his career, having used only single-stage presses all his life. A High Master NRA High Power Rifle competitor, he had no background in competitive pistol shooting, where historically most progressive presses are found.
Experienced Action Pistol shooters have typically encountered multiple episodes in which shooters “skipped” a powder charge for some reason, leading to a squib round and a bullet possibly lodged in the bore. Thus, at matches, it’s reflexive for them to yell “STOP!” in unison if they see a shooter get a “click” vs. a “bang”, and rack the slide to keep firing. This writer has personally seen several pistols saved in just such scenarios over the years.
Click No Bang — What NOT to Do
Our High Master set up a popular progressive press and began turning out .223 Rem 100-yard practice ammo with abandon. He was using a moly-coated 52gr match bullet and an economical, fast-burning surplus powder that gave great accuracy. Once on the range, he began practicing strings of rapid-fire. All was well, until he heard “Click!” rather than “Boom”.
Lacking the above experience or onlookers to halt him, he reflexively operated the charging handle on his expensive, custom NM AR15 Service Rifle, and the next trigger squeeze reportedly registered on seismographs over at least a three-state radius. He sat, uninjured but bewildered, until the hail of expensive bits and pieces quit raining down around him.
When the smoke cleared, he immediately cursed the horrid, evil, demonically-possessed progressive press for this, his first-ever reloading mishap. His $1400 NM upper was ruined, but thankfully, his $800 pre-ban lower… and he had escaped injury.
This tale is told not to discourage the use of progressive presses, but to emphasize the need to EASILY and IMMEDIATELY KNOW what is happening with the press at each station, every time the handle is cranked. Not to do so is, as they say, “bad ju-ju.”
It illustrates why we at the USAMU Handloading Shop agree in recommending that new handloaders should begin with a single-stage press. Once one thoroughly learns the steps in each phase of handloading by repeated experience, then one will be qualified to move on to a progressive press.
The single-stage press will REMAIN virtually indispensable for one’s entire handloading career, even after having purchased a progressive press (or two). There are endless small projects that are best handled on a single-stage press, and a poll of USAMU’s Handloading staff reveals that not one would willingly be without his single-stage press, despite owning at least one progressive.
Here is a great winter project for readers with some wood-working skills. This is a wood rack that can hold a huge collection of sizing and seating dies. This was created by our old friend John Adams, one of our Forum’s very first members. Sadly, John passed away a decade ago. But we know he’d be pleased to see folks create a die rack like this.
John, a founder of IHMSA and a former owner of SAECO Tool Company, had a vast collection of dies and reloading tools. He had rifles of many different calibers so he needed a large selection of dies. While visiting John’s workshop, we were impressed with the wooden die rack he has constructed above his main reloading bench. This would be a great do-it-yourself project for your reloading room.
John’s Loading Die Rack is a simple flat plank of wood, about 3/4″ thick. It is mounted with wood side brackets to stand at eye-level above a tool chest. The Rack is set at about a 45° angle from vertical. This holds the dies securely, but they are still easy to move in and out of the rack. At the top rear is a flat section with a single row of dies mounted upright.
You can see that all the dies for a particular cartridge are arranged in a column, one above the other. The die sets’ respective cartridge types (e.g. 6 PPC, 6×47 Lapua, and 6XC) are marked with highly visible labels made with a label-printing machine. John also placed labels on many of the dies themselves.
Vintage RCBS Die Rack
Below is an older, metal die rack. These were once manufactured by RCBS, but they are no longer sold. John Adams managed to snag a couple from RCBS years ago. The design is handy, but you can achieve the same results with a home-made wood block (perhaps that’s why RCBS discontinued its metal rack).
Quick Access vs. the Rust Factor
WARNING: While it is handy to keep your dies in a rack, this leaves them exposed to the elements. If you reload in a basement or garage where it gets cold and damp, your dies will rust much more quickly out in the air than if they are kept enclosed in their original boxes, with a small desiccant pack. Always keep a thin layer of oil or corrosion blocker on your dies. We recommend Eezox or Corrosion-X for that task.
In June 2020, Hornady introduced the 6mm ARC, a new SAAMI cartridge optimized for AR-platform rifles*. The new 6mm ARC is basically a 6.5 Grendel necked down to 6mm, with the shoulder moved back around .030″. That pushed-back shoulder does reduce case capacity (and velocity), but we assume Hornady did that to create a shorter, proprietary chamber so people could not simply neck-down Lapua 6.5 Grendel brass, as has been done for years with Robert Whitley’s outstanding 6mm AR wildcat.
What Is the 6mm ARC Cartridge? The 6mm ARC cartridge is a new SAAMI-spec cartridge based on the 6.5 Grendel case necked down for 6mm bullets, with the shoulder moved back 0.030. Yes it is designed to run in AR15-platform rifles. You’ll need a new barrel, bolt, and mags. If you already have an AR chambered in 6.5 Grendel, the ONLY thing you need to change is the barrel. Everything else — bolt, magazines, gas system – is compatible with 6mm ARC.
▶ Official SAAMI Cartridge (not wildcat)
▶ Fits standard AR15-platform rifles
▶ Fits Short/Mini action bolt rifles
▶ Efficient short, fat case design
▶ 30-degree case shoulder
What Do I Need To Shoot the 6mm ARC?
Faxon and Ballistic Advantage are already producing barrels, with more manufacturers sure to follow. All the other required components are already on the market for 6.5 Grendel rifles. Aero Precision already offers complete 6mm ARC uppers.
If you’re converting a standard 5.56×45 mm (.223 Rem) AR15 upper to shoot 6mm ARC, you’ll need a 6mm barrel, a Type II 6.5 Grendel bolt carrier group, and new magazines. Some folks have suggested standard AR mags will work, but trust us, you want the magazines that have been designed for 6.5 Grendel. Most of the hardware you need is available at Brownells.
* While 6-6.5 Grendel shooters are known to run stout pressures, the new 6mm ARC cartridge has a relatively moderate Maximum Average Pressure (MAP) rating of 52,000 psi according to the official SAAMI specifications. For a variety of reasons, is wise to keep pressures in a semi-auto rifle moderate. Don’t chase the velocities you might get in a bolt-action gun.
On the Applied Ballistics Facebook Page, there was a fascinating series of posts showing traces of bullets at various speeds from Mach 0.86 to Mach 3.0. At the slowest speed, Mach 0.86, i.e. 962 FPS, there is turbulence behind the bullet, but no clear shockwave. At the highest velocity, Mach 3.0 (3375 FPS at sea level, 68° F), there is a dramatic double nose and tail wave formation.
To learn more, visit TheScienceofAccuracy.com. On that site you’ll find exclusive video content and you can subscribe to member’s only Podcasts. And you can purchase Applied Ballistics books on the Science of Accuracy webstore.
Mach 3.00 Bullet Flight Image
At Mach 3 (3355 FPS) this bullet now has a strong and well established shock wave forming at the tip, and at the base. Unlike the transition through Mach 1.0, nothing really interesting happens to the aerodynamics or shock waves meaning the aerodynamics and stability are: continuous, easy to predict, and model. As you go faster, the shockwaves make a shallower angle because the bullet is moving forward 3X faster than the shock wave is moving away from it. So the shock wave makes an angle that has a rise/run ratio of 1/3.
If a bullet flew within 10 feet of you traveling this fast, it would be about as loud as a 22 magnum. You’d certainly want hearing protection as the energy contained in a Mach 3 shock wave is high! How high…? Well, in 10 yards, this bullet slows from 3355 FPS to 3334 FPS in a time of 0.0090 seconds. The 55 ft-lb of kinetic energy lost during this 10 yards is due to aerodynamic drag on the bullet, which is comprised of wave, base, and skin friction drag components with the majority of the drag being due to shock wave formation. Expending 55 ft-lb of energy in 0.0090 seconds requires a power output of 6111 ft-lb/sec = 11.1 horsepower, most of which goes into creating the shock wave. Remember it’s a 3-D cone that travels great distance, and it gets its energy by stealing velocity from your bullet!
Mach 1.00 Bullet Flight Image
Many shots were fired to capture an image of the transonic shockwave structure at exactly Mach 1.00. With the bullet now moving at the speed of sound, the local airflow on some parts of the bullet exceeds Mach 1.0. Anytime something is moving thru the air faster than the air can get out of the way, you get a compression wave, aka “shock wave”. That’s what’s visible in this image — the areas where the air density changes rapidly (in the compression wave) are visible as near vertical lines and a detached bow wave out front. As the bullet progresses through transonic speed, this shockwave structure develops which has strong effects on the drag (wind sensitivity) and stability of the bullet.
The exact development of the shockwaves and the resulting effects are unique and sensitive to the bullet geometry, and become very difficult to predict through the transition from subsonic (incompressible flow without shock waves) to supersonic (compressible flow with shock waves). Each bullet geometry does this differently which is why it’s difficult to determine transonic stability criteria for bullets of different shapes.
Mach 0.86 Bullet Flight Image
Here’s a bullet at Mach 0.86 (86% the speed of sound, which is 962 FPS at 61° F). As you can see, this 0.86 Mach is not fast enough to make any discernable waves but you can see turbulence in the bullet wake (right side in photo). The beginning of small shock waves can be seen on the bullet tip, and at the bearing surface/boat tail juncture. For the most part, all of the airflow around this bullet is subsonic. You wouldn’t hear a supersonic ‘crack’ from this bullet flying past the observer.
Small patches are not very efficient at distributing bore cleaning liquids inside your bore. The problem with a tight-fitting patch is that the solvent gets squeezed off in the first few inches. You can switch to a smaller jag, or a bore mop, but there is an even better way to get an ample amount of solvent in your bore. Just spray directly into the bore with a wash bottle, an inexpensive plastic bottle with an L-shaped dispensing neck, tapered at the end.
When using the wash bottle, you can either just plug the breech and spray from the muzzle end (where most copper fouling is), or, alternately, put the wash bottle neck directly in the chamber and spray forward. When spraying from the chamber forward, you may need to use a rubber O-Ring to seal off the action… depending on the bore size and the particular wash bottle’s neck spout diameter. We prefer to plug the breech and squirt from the muzzle.
Bottle Solvent Application Method Works Great for Smaller Bores
Using wet patches or wet brushes is an inefficient way to really saturate the tight bores of 17s, 20s, and 22s. Even with a cotton bore mop, most of the solvent will be squeezed out before it gets to the end of the bore, where most copper fouling occurs. For these smaller 17, 20, and 22-caliber bores, you can just take the wash bottle and stick the tapered nozzle right in the chamber. The tapered end will press fit in the throat, sealing off the chamber. With the barrel slightly nose-down, give the bottle a couple good squirts until the solvent mists out the muzzle. In just a few seconds, this will put more solvent in the bore than a half-dozen wet patches.
A solvent-filled wash bottle is also handy for wetting your brushes. It’s much easier to saturate a bore brush (without spilling solvent on your stock), by using the wash bottle. You can get wash bottles from USPlastic.com, Amazon.com, or lab supply stores. CLICK HERE to get a pair of wash bottles for just $5.99.
The Risk of Hearing Loss
Quality foam earplugs offer great hearing protection at low cost. These Howard Leight 
Small patches are not very efficient at distributing bore cleaning liquids inside your bore. The problem with a tight-fitting patch is that the solvent gets squeezed off in the first few inches. You can switch to a smaller jag, or a bore mop, but there is an even better way to get an ample amount of solvent in your bore. Just spray directly into the bore with a 
