Hardware Choices: Actions, Stocks, Barrels, Optics and More Tech Talk by Jeff Stover
This article was prepared by past IBS President Jeff Stover based on results from the 2019 IBS 100/200 Group Nationals held August 12-17, 2019 at the Holton Gun & Bow Club in western Michigan.
Let’s examine the Top Ten rifles from the 2019 IBS Group Nationals in the 10.5-lb Light Varmint Class. We’ll focus on the most popular rifle components — the choices for Actions, Stocks, Barrels, and Scopes.
Hall of Famer Jeff Gaidos taking aim at the 2018 IBS Group Nationals. He has a low-profile carbon-fiber stock with a Leupold fixed-power scope.
For some years now, BAT has been the predominant action. This year BAT actions held nearly 100% of the Top Ten places in all the Bag Gun equipment lists. Bruce Thom’s Idaho-crafted actions, except for a couple stray actions in Heavy Bench, swept the top rankings.
Next, look at barrels. Bartlein or Krieger seem to rule with upstate New York’s venerable Hart barrels as competitive. Shooters tend to go with winners, so Wayne Campbell and Jeff Peinhardt dominate as gunsmiths for the top benchrest shooters.
In stocks there seems to be variety, but there is some commonality. The Scoville and Scarbrough stocks, both Michigan-made, are laminated wood (balsa and other wood) with carbon fiber and wrapped in carbon fiber. The Scoville stock on my 10.5-lb rifle weighs 18 ounces but is full size with a nice long fore-end. Bob Scarbrough makes a very similar product. Both are winners — it’s a choice of Ferrari or Lamborghini. The Roy Hunter and Terry Leonard stocks among these top rifles take a different route to winner’s circle. Both are wood (cedar or other), but super high-tech as they are laminated with carbon fiber. They are beautiful to boot. High-magnification Leupold, March, and Nightforce scopes rule the roost among benchrest optics.
Bullets and Powder
Bullets are important. Really important. A hot bullet gives you “Teen Aggs” and lots of trophies. An average bullet does not. Most of these are 68 grain 6mm boattails. The Peinhardt (StaMoly Precision) bullet is well represented on this list, but some top shooters make their own as you can see. Bullet jackets are likely StaMoly or J4. For powder, nearly everyone shoots Vihtavouri N133 except a few guys running LT30/32 or surplus 8208.
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).
Montana Attorney General Knudsen Leads 18-State Effort Calling On UPS And FedEx To Clarify Gun-Purchase Tracking Polices
Seventeen state Attorneys General joined Montana Attorney General Austin Knudsen today in asking major shipping companies to clarify new policies that allow them to track firearm sales with unprecedented specificity and bypass warrant requirements to share that information with federal agencies.
Reports from Montana federal firearm license (FFL) holders made to Attorney General Knudsen’s office indicate that UPS and FedEx are now burdening them by requiring them to ship separately and track firearms, firearms parts, and firearm products so gun purchases can be tracked and retain documents about what specific items those shipments contain and make that information available to the companies upon request.
Knudsen and the coalition of attorneys general sent letters on November 29, 2022 to leadership at both companies requesting additional information on their new policies and the possibility that the effort was coordinated in part with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives (ATF).
“These demands, in tandem, allow [UPS/FedEx] to create a database of American gun purchasers and determine exactly what items they purchased… In doing so you, perhaps inadvertently, give federal agencies a workaround to normal warrant requirements. This allows [UPS/FedEx] to provide information at will or upon request to federal agencies—information detailing which Americans are buying what guns,” Attorney General Knudsen’s letters state. “Additionally, we recommend that you consider taking actions to limit potential liability moving forward, including the immediate cessation of any existing warrantless information sharing with federal agencies about gun shipments.”
In addition to requesting updated FFL-related shipping policies from the two companies, Attorney General Knudsen asked them to clarify the following:
Did UPS/FedEx enact these policies with the goal of information sharing with the ATF or any other federal agency;
Did UPS/FedEx enact these policies at the request of officials in ATF, a different federal agency, or on its own initiative;
If UPS/FedEx implemented these policies at the request of a federal agency, please identify that agency, the officials who made that request, the nature of that communication, and any legal authorization cited by those officials;
If UPS/FedEx changed its policies on its own initiative, please explain why it made those changes;
Did UPS/FedEx communicate or coordinate with each other in making these changes;
Did ATF or other federal agency employees help draft the updated shipping agreements?
Montana Attorney General Austin Knudsen led the effort. In addition, Attorneys General from Alabama, Alaska, Arkansas, Florida, Indiana, Kansas, Kentucky, Louisiana, Mississippi, New Hampshire, Ohio, Oklahoma, South Carolina, Texas, Utah, West Virginia, and Wyoming signed one or both letters.
With December just two days away, winter is here. For many Americans that means indoor training if they want to maintain their shooting skills. Even if you can shoot outdoors all year long in your location, it makes sense for position shooters to work on their rifle holds. The Mantis systems help with that. These advanced smart devices record and plot the movement of your firearm as you aim and then break the shot. There are systems for both dry-fire and live-fire training, starting at $99.99. Considering the cost of bullets these days, and the difficulty of finding primers, it makes sense to increase your dry-fire training.
Mantis X2 for Dry-Fire, $99.99
Built for dry-fire use only, the Mantis X2 ($99.99) provides real-time, shot-by-shot feedback for both pistol and rifle users. You can track multiple training sessions with data-driven insights, and monitor your progress. This unit has earned high user reviews such as: “As a new gun owner the Mantis X is a game changer for me. I have not been able to get to the range during the lockdowns and being able to practice at home [is great].” And another: “Easy to install[.] The App is free and easy to use.”
The Mantis X2 is a good value. The manufacturer states: “There is nothing at this price point that will give you this level of feedback for dry fire.” There are actually four Mantis models: X2 ($99.99), X3 ($169.99), X7 Shotgun ($199.99) and X10 Elite ($249.99). The X3 adds live fire functionality. MORE INFO HERE.
Mantis X10 Elite– Advanced Training System
The advanced Mantis X10 Elite ($249.99) is 50% lighter and 40% smaller than the original Mantis, with three times the battery life and four times the data transfer rate. This new quick-detach X10 system offers all X2 and X3 functions PLUS recoil analysis and software support for all shooting sports (pistol, rifle, shotgun, archery). Collecting thousands of data points per second, the X10 works with dry fire, live fire, airsoft/CO2, and simulated firearm systems.
Mantis Blackbeard Trigger Reset System for AR-Platform Rifles
If you compete with an AR-platform rifle, you can definitely benefit from the Mantis Blackbeard system, a drop-in Bolt Carrier + Magazine replacement that works with your existing trigger. Using electromechanical wizardry, the $199.00 Blackbeard quickly resets the hammer between each shot, so you can stay in position through multiple practice shots. Installation takes less than a minute — remove the bolt carrier group, drop in the red upper unit, place the red Mantis magazine and you’re good to go. All Blackbeards now support both direct impingement and piston-driven ARs. Guys we know say that a few sessions with this system delivered marked improvement in their service rifle scores.
Mantis X3 for Live-Fire or Dry-Fire, Rifle and Pistol
The Mantis X3 collects thousands of data points per second and analyzes your shooting in real-time. For both pistols and rifles, the X3 works with dry fire and live fire. It will also work with airsoft/CO2/compressed air, and simulated firearm systems. Priced at $169.99, the Mantis X3 mounts to standard universal accessory rails. (No Picatinny rail? Creedmoor Sports sells adapters). The X3 is part of the second generation of Mantis Shooting Performance Systems.
GunsAmerica Digest has just released a series of articles with some great gift suggestions for the holiday season. Five different writers have posted suggestions for particular gift categories — such as gifts for lady shooters, gifts for tactical shooters, or gifts for suppressor fans. The suppressor feature is by GunsAmerica Digest Editor True Pearce. Here are links to the five articles:
Of the many items listed, here are three of our favorites. You’ll find many more in the five GunsAmerica Digest articles linked above.
Savage B22 FV-SR .22 LR Rifle
As noted by GunsAmerica Digest Editor True Pearce, this little Savage is a good starter rimfire rifle: “Savage’s bolt action B22 FV-SR .22 is perfect for suppressing. They’re … accurate, reliable, come threaded for a suppressor, and with subsonic ammo, they’re … quiet[.] MSRP is only $359.”
Mantis Laser Academy Training Kit
The Mantis Laser Academy Standard Training Kit allows you to practice marksmanship indoors with wireless communication. This kit includes: laser training cartridge, adjustable tripods, smart targets, target stand holders, portable carrying case, and a Mantis Laser Academy access code — all for $149.00.
Silencer Central Banish Rimfire Suppressor
True Pearce notes: “Silencer Central’s Banish .22 is a great little suppressor that works on pretty much all rimfires including 17 HMR.” The Banish .22 suppressor is very light at just 4.1 ounces, and it can be easily taken apart for cleaning. MSRP is $499.00 and that fee includes a gun trust.
Winter is definitely here, with December just days away. Even now there is an abundance of snow on the ground in many parts of the country. 2022 has brought some unusually cold weather to many regions — witness the recent deluge of snow in upstate New York.
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.
Winter Hunting — Success with Snow on the Ground
There has been snow on the ground for much of November in many areas of the country. Hunters have had to cope with the snow and cold temperatures. Our hunting editor, Colton Reid, recently returned from a successful deer hunt in the mountains of Utah. He said it was beautiful, but you needed really high-quality outdoor clothing — otherwise you could get in trouble. You need to stay warm and dry.
With careful planning, and some skilled tracking, Colton had success, making a perfect hit on a buck at 300 yards. The animal dropped instantly. Colton brought back a good harvest of deer meat, which formed part of the Thanksgiving feast for his family.
Colton offered these 5 TIPS for hunters. These apply in any season, but are even more important in winter with freezing temps and snow on the ground:
1. Have a Plan — know where you plan to go and when. Try to be where you want in the early morning and early evening hours when deer are likely most active.
2. Take Your Time — If you spot a deer and get too excited and don’t take your time you may spook him. Go slow and glass. If possible, wait for the animals to bed down and relax. Then work out the best way to approach your prey. Remember, “You get so few opportunities, don’t screw it up!”
3. Glass More, Walk Less — Let your eyes do the walking — get good binoculars and use them. With their heightened senses of smell and hearing, deer/elk are able to spot you way better than you can spot them. If you are walking around a lot, chances are you are getting spotted by your prey.
4. Pace Yourself When Packing Out — If you DO succeed, and bring down a big buck, will you be able to dress the animal and carry out the meat? Always be prepared to hike out with extra weight. If you are successful, make sure not to waste the meat you worked so hard for. Choose a pack that can help you carry a heavy load. Remember, this is not an insignificant challenge — you may be carrying 60 to 100 extra pounds in addition to your other gear. Again, take your time. Rest as needed. Don’t hurt yourself.
5. Always Enjoy the Experience — Have fun, and appreciate your hunt, whether you bag a buck or not. It is a privilege to experience the wilderness and to get away from the city. Enjoy it while you’re out there. And keep your spirits up. You may get tired, but remember that ‘comes with the territory’. At the end of the day, yes you may be exhausted. And you may want to quit and go home. But stay positive, stay focused. Be patient, the experience is worth it.
Winter Solace in the Backcountry
There is a nice thread in our Forum appropriately entitled “Winter Time”. You’ll find some great backcountry images taken by our Forum members. Winter is a special time in the outdoors. Forum member JDP explains: “Winter is the best time to shoot! One of the few of life’s ironies that works in my favor. The range is empty and barrels keep cool, no bugs, no waiting on people, no mirage. Yup, this world needs more thin blooded snow birds. This cool weather is terrible and dangerous, tell your friends! Do people get lonely while shooting or something? It’s the true holiday season in multiple ways.”
Forum member DNorton posted: “I live way up north where our white sandy beaches look like this!”
Our friend Robert Whitley of ARX Enterprises LLC has learned, through careful measurement and testing, that some barrels threaded 5/8″ x 24 TPI at the muzzle may not deliver optimal accuracy. The reason is that the end of the barrel can bell out slightly, like a trombone, because too much steel has been removed. This is particularly true with .30-caliber barrels, but it can also be a problem with smaller caliber barrels (even 6mm). Robert demonstrates this phenomenon in the video below. All gunsmiths, and anyone considering threading a barrel, should watch the video. At 1:00 – 1:30 Robert gauges a 5/8″ x 24-threaded .30-Caliber barrel. You can see the belling effect clear as day.
“When setting up a commercial barrel in the lathe, we noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015” smaller [than what would fit] at the muzzle. That precipitated my pin-gauging of a number of different commercial barrels that were threaded for 5/8” x 24 TPI. What I found is what’s shown on the video.” – R. Whitley
Solve Problem with a Larger Thread Diameter
If 5/8″ x 24 threading is potentially harmful to accuracy, is there a solution? Yes, you simply need to leave a little more steel on the barrel. (See Video starting at 02:40.) Frank Green of Bartlein barrels states: “We get these questions all the time. I say run the largest thread diameter that is possible.” Robert Whitley has found that a 3/4″ x 28 TPI threading does not cause the “belling effect”. Accordingly Robert recommends 3/4″ x 28 if you need to thread your barrel for a muzzle brake or suppressor. Robert explains: “We only make 3/4” x 28 TPI muzzle brakes and that’s what we recommend to customers.”
“See how much meatier the 3/4″ threading is vs. the 5/8″. The 3/4″ threading offers a lot more metal around the bore. There’s a lot less opportunity for the bore to become bell-mouthed…” – Robert Whitley
Barrel Threading Diameter — What’s Important to Know
By Robert Whitley
In truth, the 5/8″ x 24 TPI threading never came out of any accuracy-based think tank or set-up, it’s a military .30-Cal threading for barrels that someone has to carry around (they needed to keep the barrel weight down so it was smaller in diameter and the threading had to work with that situation). People have somehow assumed because the military uses that threading for certain things that it must mean that it’s also fine for a highly accurate rifle too, but that’s not really correct.
I don’t think there is any better and realistic option than the 3/4″ muzzle threading, and we also do it so there is no relief cut behind the threads on the barrel (i.e. put the relief cut on the brake or jam nut, don’t chop down on the muzzle of the barrel). For some reason many have a hard time grasping that the metal at the muzzle end of a rifle is “sacred” and you should not cut it down any more than absolutely necessary. A little threaded pencil diameter nub on the end of a barrel is not ideal for accuracy especially if it’s threaded and you need to torque on it. I cringe when I see a barrel with something like an MTU or Heavy Varmint contour, only to have an itty-bitty pencil thin threaded nub right at the muzzle so someone can “screw on a can” or a muzzle brake.
Lessons Learned Over the Years
A number of years ago I did a 30BR rifle project with Craig Kostyshyn who was big in the 30BR game and he made some of the best 30BR rifle barrels for benchrest competition. When I did the project I wanted a medium-heavy Palma type contour barrel I could use and also have a muzzle turndown for a front sight band. When he found out I was going to have the muzzle turned down he said “whoa, I need to provide for that when I make the barrel because if you turn the front down later you’ll be shooting a trombone” (i.e. the muzzle bore dimension would open up).
What he did was rough contour the barrel with the turndown (about .010” oversize) before he lapped the barrel, then when he lapped the barrel he took it easy in the muzzle area and worked the back of the barrel more. I thought he was a little bit excessive in his concerns but the barrel shot great and I wasn’t going to argue with him, after all he was shooting groups in the ones. I kind of just filed that away and never thought about it until recently when I went to have Fred from Sabreco do some chamber re-work on a commercial .30-caliber barrel I had. When setting up the barrel in the lathe and indicating things Fred noticed that the maximum-sized bushing that would fit in the bore at the chamber end was almost .0015″ smaller [than what would fit] at the muzzle and he mentioned it to me. That precipitated my pin-gauging of a number of different commercial barrels I had that were threaded for 5/8” x 24 TPI. What I found is what’s shown on the video.
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Today, November 24th, is Thanksgiving. That means a large percentage of Americans will be on the road to visit relatives. We know many of our readers have concealed carry permits or will otherwise be traveling with firearms. When crossing into different states with guns in a vehicle, you need to be mindful of all state and local laws and restrictions.
Five Worst States for Traveling with Firearms
This article appears in the Cheaper Than Dirt Shooter’s Log.
The U.S. is a patchwork of confusing and cumbersome laws that change the rules of what you can carry, where you can carry, and whether you can possess the firearm, ammunition of magazine at without running afoul of the local laws. Now, if every state was like Vermont, law abiding gun owners could freely travel with their firearms with no worries. Unfortunately, many states have a history of being hostile to traveling gun owners.
The federal “Firearms Owner Protection Act” allows travel through any state as long as the firearm is unloaded, in a locked case, and not easily accessible to the passengers. However, that is not to say that certain states that are less friendly to firearms have not created their own laws that would snare unsuspecting otherwise law-abiding firearm owners. This led us to name the Top 5 States to Avoid while traveling with a firearm this holiday season.
CONNECTICUT
Connecticut does not have any gun reciprocity agreements with other states. This means nonresidents are not allowed to carry handguns in Connecticut under a permit issued by another state.
HAWAII
Every person arriving into the state who brings a firearm of any description, usable or not, shall register the firearm within three days of the arrival of the person or the firearm, whichever arrives later, with the chief of police of the county where the person will reside, where their business is, or the person’s place of sojourn. GET Hawaii Firearms INFO HERE.
MASSACHUSETTS
Massachusetts imposes harsh penalties on the mere possession and transport of firearms without a license to carry. Prospective travelers are urged to contact the Massachusetts Firearms Records Bureau at (617) 660-4780 or contact the State Police. GET Massachusetts Firearms INFO HERE.
NEW JERSEY
New Jersey has some of the most restrictive firearms laws in the country. Your firearm must be unloaded, in a locked container, and not accessible in the passenger compartment of the vehicle. The New Jersey Supreme Court ruled that anyone traveling within the state is deemed to be aware of these regulations and will be held strictly accountable for violations. If you’re traveling through New Jersey, the N.J. State Police website provides information regarding transporting firearms within state lines. GET New Jersey Firearms INFO HERE.
NEW YORK
Use extreme caution when traveling through New York state with firearms. New York’s general approach is to make the possession of handguns and so-called “assault weapons” illegal. A number of localities, including Albany, Buffalo, New York City, Rochester, Suffolk County, and Yonkers, impose their own requirements on the possession, registration, and transport of firearms. Possession of a handgun within New York City requires a New York City handgun license or a special permit from the city Police Commissioner. This license validates a state license within the city. Even New York state licenses are generally not valid within New York City unless a specific exemption applies. Possession of a shotgun or rifle within New York City requires a permit, which is available to non-residents, and a certificate of registration.
More Scary States for Gun Owners
Here are six other jurisdictions (five states and DC) where you need to be wary when traveling. California, for example, treats all handguns in vehicles as “loaded” if there is ammunition loaded into an attached magazine. It’s wise, when in California, to have handguns unloaded in a LOCKED case, with all ammunition or magazines in a separate section of the vehicle. These states (and DC) all have laws that can trap unsuspecting gun-owners. Be wary.
California
Delaware
Dist. of Columbia
Illinois
Maryland
Rhode Island
Shooting Sports USA (SSUSA) offers a wide selection of informative articles on marksmanship techniques. If you shoot prone, “hard-holding”, you know how important proper positioning and technique can be. There is a SSUSA article that every prone shooter should read — whether you shoot air rifle, smallbore, or High Power. Compiled wtih the help of some of the country’s best prone marksmen, this article, How to Master Prone Shooting, provides a step-by-step guide to perfecting your prone position technique.
How to Master Prone Shooting — SSUSA by NRA Staff
The prone position is the most precise of the rifle shooting positions. It is used in many different shooting events at distances as close as 5 meters and as far away as 1,000 yards, and beyond that in long-range disciplines such as PRS and NRL. Prone shooting is very popular among shooters whose training time is limited, because it does not require as much practice. Age has little effect on a shooter’s ability to do well in prone; many older shooters are able to continue competing successfully in prone matches.
Here is a sample, listing STEP ONE, the basics of the prone position:
Step One: Study the Position
The prone position is steady because it is low, which gives a wide base of support to help keep the rifle still. Below are the key features of the prone position.
1. Straight line form left hand through left arm, side and leg.
2. Head tipped down comfortably.
3. Right hand grips rifle lightly.
4. Body lies behind rifle. Angle to rifle is 10 to 20 degrees.
5. Right knee bent slightly, toe pointing out.
6. Rifle lies on heel of left hand, fingers relaxed.
7. Left elbow rests to left of rifle.
8. Sling (if present) supports weight of rifle. Left arm relaxed.
9. Body rests slightly more on left side.
10. Left leg straight, toe pointing inward or straight back.
There are FIVE MORE STEPS described in detail with specific actions to perform, in the FULL Article. For example, in STEP FOUR (Sling Adjustment), the article explains: “Put the sling high on the arm and tighten the sling keeper. Wrap the arm around the sling so that the sling comes across the left hand and forearm.”
“A bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, the bullet behaves as if it has a higher ballistic coefficient.”
Last month a good friend ventured to the high country of Colorado to pursue elk. He recently zeroed his rifle in California, at a range just a few hundred feet Above Mean Sea Level (AMSL). He wondered if the higher altitude in Colorado could alter his ballistics. The answer is a definite yes. However the good news is that free ballistics calculators can help you plot reliable drop charts for various shooting locations, high or low.
The question has been posed: “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, at higher altitudes, the bullet behaves as if it has a higher ballistic coefficient.
Forum member Milanuk explains that the key factor is not altitude, but rather air pressure. Milanuk writes:
“In basic terms, as your altitude increases, the density of the air the bullet must travel through decreases, thereby reducing the drag on the bullet. Generally, the higher the altitude, the less the bullet will drop. For example, I shoot at a couple ranges here in the Pacific Northwest. Both are at 1000′ AMSL (Above Mean Sea Level) or less. I’ll need about 29-30 MOA to get from 100 yards to 1000 yards with a Berger 155gr VLD at 2960 fps. By contrast, in Raton, NM, located at 6600′ AMSL, I’ll only need about 24-25 MOA to do the same. That’s a significant difference.
Note that it is the barometric pressure that really matters, not simply the nominal altitude. The barometric pressure will indicate the reduced pressure from a higher altitude, but it will also show you the pressure changes as a front moves in, etc. which can play havoc w/ your calculated come-ups. Most altimeters are simply barometers that read in feet instead of inches of mercury.”
As Milanuk states, it is NOT altitude per se, but the LOCAL barometric pressure (sometimes called “station pressure”) that is key. The two atmospheric conditions that most effect bullet flight are air temperature, and barometric pressure. Normally, humidity has a negligible effect. It’s important to remember that the barometric pressure reported on the radio (or internet) may be stated as a sea level equivalency. So in Denver (at 6,000 feet AMSL), if the local pressure is 24″, the radio will report the barometric pressure to be 30″. If you do high altitude shooting at long range, bring along a Kestrel, or remember to mentally correct the radio station’s pressure, by 1″ per 1,000 feet.
Trajectory of Bullet fired at Sea Level
Trajectory of Bullet fired at 20,000 feet
You can do your own experimental calculations using JBM Online Ballistics (free to use). Here is an extreme example, with two printouts (generated with Point Blank software), one showing bullet trajectory at sea level (0′ altitude) and one at 20,000 feet. For demonstration sake, we assigned a low 0.2 BC to the bullet, with a velocity of 3000 fps.
To learn more about all aspects of Exterior Ballistics, Hornady has a useful discussion of External Ballistics including the effects of altitude and temperature. To dig deeper, Sierra Bullets has a comprehensive Exterior Ballistics Resource Page with multiple sections from the Sierra Manual (4th and 5th Editions), including:
Example from Section 3.0: “When a bullet flies through the air, two types of forces act on the bullet to determine its path (trajectory) through the air. The first is gravitational force; the other is aerodynamics. Several kinds of aerodynamic forces act on a bullet: drag, lift, side forces, Magnus force, spin damping force, pitch damping force, and Magnus cross force. The most important of these aerodynamic forces is drag. All the others are very small in comparison when the bullet is spin-stabilized.”
With careful planning, and some skilled tracking, Colton had success, making a perfect hit on a buck at 300 yards. The animal dropped instantly. Colton brought back a good harvest of deer meat, which formed part of the Thanksgiving feast for his family.
The question has been posed: “What effect does altitude have on the flight of a bullet?” The simplistic answer is that, at higher altitudes, the air is thinner (lower density), so there is less drag on the bullet. This means that the amount of bullet drop is less at any given flight distance from the muzzle. Since the force of gravity is essentially constant on the earth’s surface (for practical purposes), the bullet’s downward acceleration doesn’t change, but a bullet launched at a higher altitude is able to fly slightly farther (in the thinner air) for every increment of downward movement. Effectively, at higher altitudes, the bullet behaves as if it has a higher ballistic coefficient.
