This popular video, viewed 3.8 million times on YouTube, provides a clear explanation of Minute of Angle (MOA) and how that angular measurement is used. Among novice shooters, there is much confusion over this term. In this NSSF Video, Ryan Cleckner, a former Sniper Instructor for the 1st Ranger Battalion, defines the term, “Minute of Angle” (MOA) and explains how you can adjust for windage and elevation using 1/4 or 1/8 MOA clicks on your scope. This allows you to sight-in precisely and compensate for bullet drop at various distances.
For starters, Ryan explains that, when talking about angular degrees, a “minute” is simply 1/60th. So a “Minute of Angle” is simply 1/60th of one degree of a central angle, measured either up and down (for elevation) or side to side (for windage). At 100 yards, 1 MOA equals 1.047″ on the target. This is often rounded to one inch for simplicity. Say, for example, you click up 1 MOA. That is roughly 1 inch at 100 yards, or roughly 4 inches at 400 yards, since the target area measured by 1 MOA increases in linear fashion with the distance.
More Minute of Angle (MOA) Explanatory Videos
This Gunwerks video explains that Minute of Angle subtends approximately 1″ for each 100 yards (well, 1.047″ to be more precise). That means a Minute of Angle increases in actual measured size the greater the distance of the target from the shooter.
This lengthy (24-minute) video defines Minute of Angle, and uses multiple diagrams to illustrate how MOA angular measurements works. The video also how MOA-based click values translate to point-of-impact changes at various distances.
From time to time, we all encounter a primer that doesn’t go off. It’s normal to attribute the problem to a bad primer. But sometimes there are other explanations. George S., one of our Forum members, experienced a couple failures to fire, but he learned that the issue was his priming TOOL, not his primers. Here’s what George told us. There’s a lesson to be learned:
“I had issues with CCI 450s when I had my first 6BR barreled. I had probably three or four out of 20 rounds that failed to fire. the primers were dented but didn’t fire. I called CCI since I had bought a case of them. The tech was decent enough but had the audacity to tell me I was not seating the primers all the way in the pocket. I proceeded to let him know I had been reloading longer than he had been alive and I knew how to seat a primer.
Turns out that I did and I didn’t! I was using the RCBS primer tool I had used for years and the primers felt just fine to me. I finally decided to check the tool and since I had a new one I took the seating pins out and measured them. The seating pin on the tool I had been using for years was shorter by a few thousandths! I then used the pin from the new primer tool and darned if the primers that didn’t seat down to the bottom of the cup.
I switched to a K&M primer tool for seating the CCI primers and have not had a problem since. It was the combination of harder cup and lack of proper seating. I did call the CCI tech back and apologized for being an idiot.”
Another Forum member witnessed a problem cause by misuse of a priming tool: “I did … see a failure to fire on a Rem 9 1/2 primer only a week ago. That was in the new Rem muzzleloader that uses a primed case to ignite the pellets. After watching the muzzleloader’s owner seat his primers, I believe that it was operator error not the primer. He was seating the primer and then squeezing the priming tool so hard that his hands hurt after a few. We got that corrected.”
Team Smith & Wesson shooter Julie Golob has a message for Mother’s Day (Sunday, May 12th). Julie writes: “While some are using Mother’s Day week to push a gun control agenda, I’d like to encourage moms to ‘Take a Moment’. Talk to your kids about firearms safety. Help them learn what to do around firearms and have an open, honest discussion about guns and gun safety.
I truly believe that, no matter if you are pro-gun or anti-gun, everyone should know and understand the basic rules of firearm safety. It is equally important for parents to have the discussion about guns and what to do if your child finds one. Both the NSSF’s Project ChildSafe and the NRA’s Eddie Eagle GunSafe® Program are excellent. They offer resources for parents, educators, and child care providers to help ensure kids stay safe.
In this video, Julie encourages parents to have “the talk” about firearm safety with their kids sooner rather than later, and provides tips for how to have a helpful discussion. Sherra Scott, a mom and a certified NRA instructor, agrees with Julie: “Whether you have firearms in your home or not, if you have children in your life, please watch this video and talk WITH them about firearm safety and what to do if they come into contact with a firearm.”
Here are two different bullet types, seated to the same CBTO length, but different COAL. Note the shiny scratches on the bullets made by the comparator tool which indicates a point on the bullet ogive near where the ogive will engage the rifling.
Effects Of Cartridge Over All Length (COAL) And Cartridge Base To Ogive (CBTO) – Part 2 by Bryan Litz forBerger Bullets. Part One of this series focused on the importance of COAL in terms of SAAMI standards, magazine lengths, seating depths, and pressure levels. Another measure of length for loaded ammunition is highly important to precision, namely Cartridge Base to Bullet Ogive Length (CBTO).
Figure 2. Chamber throat geometry showing the bullet jump to the rifling or lands.
Look at Figure 2. Suppose the bullet was seated out of the case to the point where the base of the bullet’s nose (ogive) just contacted the beginning of the riflings (the lands) when the bolt was closed. This bullet seating configuration is referred to as touching the lands, or touching the riflings and is a very important measurement to understand for precision hand-loading. Due to the complex dynamics of internal ballistics which happen in the blink of an eye, the distance a bullet moves out of the case before it engages the riflings is highly critical to precision potential. Therefore, in order to systematically optimize the precision of his handloads, it’s critically important that the precision hand-loader understands how to alter bullet seating depth in relation to the barrel rifling. Part of the required knowledge is understanding how to accurately and repeatably measure the Cartridge Base To Ogive (CBTO) dimension. This is explained in the FULL ARTICLE.
Bryan Litz offers an extended discussion on how to measure CBTO using different tools and methods, including the Hornady OAL gauge. You can read this discussion in the full article found on the Berger Bullets website. CLICK HERE to Read Full Article.
Why Not Use CBTO as a SAAMI Standard?
If CBTO is so important to rifle accuracy, you might ask, “Why is it not listed as the SAAMI spec standard in addition to COAL?” There is one primary reason why it is not listed in the standard. This is the lack of uniformity in bullet nose shapes and measuring devices used to determine CBTO.
Benefits of Having a Uniform CBTO
There is another aspect to knowing your CBTO when checking your COAL as it pertains to performance. With good bullets, tooling, and carefully-prepared cases you can easily achieve a CBTO that varies less than +/- .001″ but your COAL can vary as much as .025″ extreme spread (or more with other brands). This is not necessarily bad and it is much better than the other way around. If you have a CBTO dimension that varies but your COAL dimension is tight (within +/- .002″) then it is most likely that your bullet is bottoming out inside the seater cone on the bullet tip. This is very bad and is to be avoided. It is normal for bullets to have precisely the same nose shape and it is also normal for these same bullets to have nose lengths that can vary as much as .025″.
Summary of Cartridge Base To Ogive (CBTO) Discussion
Here are four important considerations regarding bullet seating depth as it relates to CBTO:
1. CBTO is a critical measurement to understand for handloaders because it’s directly related to precision potential, and you control it by simply setting bullet seating depth.
2. Tools and methods for measuring CBTO vary. Most of the measurement techniques have pitfalls (which may give rise to inconsistent results) that you should understand before starting out.
3. A CBTO that produces the best precision in your rifle may not produce the best precision in someone else’s rifle. Even if you have the same rifle, same bullets, same model of comparator gauges, etc. It’s possible that the gauges are not actually the same, and measurements from one don’t translate to the same dimension for another.
4. Once you find the CBTO that produces the best precision in your rifle, it’s important to allow minimal variation in that dimension when producing quality handloads. This is achieved by using quality bullets, tooling, and properly preparing case mouths and necks for consistent seating.
Put the same load in a variety of barrels (with the same length and chamberings) and you’ll see a wide variance in muzzle velocity. In fact, it’s not unusual to see up to 100 fps difference from one barrel to the next. We demonstrated this with a comparison test of Lapua factory ammo.
Chron Testing Lapua Factory Ammo
At our Southern California test range some years ago, we chronographed Lapua 105gr 6mmBR factory ammo in three different 8-twist barrels of similar length. The results were fascinating. Lapua specs this ammo at 2790 fps, based on Lapua’s testing with its own 26″ test barrel. We observed a speed variance of 67 fps based on tests with three aftermarket barrels.
Barrel Velocity Variance
Brand ‘S’ and Brand ‘PN’ were pre-fit barrels shot on Savage actions. Brand ‘K’ was fitted to a custom action. All test barrels were throated for the 100-108 grain bullets, though there may have been some slight variances in barrel freebore. With a COAL of 2.330″, the rounds were “jumping” to the rifling in all barrels.
Among the four barrels, Brand ‘PN’ was the fastest at 2824 fps average — 67 fps faster than the slowest barrel. Roughly 10 fps can be attributed to the slightly longer length (27″ vs. 26″), but otherwise this particular barrel was simply faster than the rest. (Click Here for results of 6mmBR Barrel Length Velocity Test).
IMPORTANT: Results Are Barrel-Specific, Not Brand-Specific
These tests demonstrate that the exact same load can perform very differently in different barrels. We aren’t publishing the barrel-makers’ names, because it would be wrong to assume that ‘Brand X’ is always going to be faster than ‘Brand Y’ based on test results from a single barrel. In fact, velocities can vary up to 100 fps with two identical-spec barrels from the SAME manufacturer. That’s right, you can have two 8-twist, 26″ barrels, with the same land-groove configuration and contour, from the same manufacturer, and one can be much faster than another.
Don’t Demand More Than Your Barrel Can Deliver
We often hear guys lament, “I don’t get it… how can you guys get 2900 fps with your 6BRs and I can only get 2840?” The answer may simply be that the barrel is slower than average. If you have a slow barrel, you can try using more powder, but there is a good chance it may never run as fast as an inherently fast barrel. You shouldn’t knock yourself out (and over-stress your brass) trying to duplicate the velocities someone else may be getting. You need to work within the limits of your barrel.
Factory Ammo Provides a Benchmark
If you have a .223 Rem, 6mmBR, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, 6.5×55, .308 Win, .30-06 Springfield, or .338 LM Rifle, we recommend you buy a box of Lapua factory-loaded ammo. This stuff will shoot great (typically around half-MOA), and it can give you a baseline to determine how your barrel stacks up speedwise. [Editor’s NOTE: The original test was conducted in 2008. The velocity of current-production Lapua factory ammo might be higher or lower, so your results may vary.]
When you complete a new 6mmBR rifle, it’s definitely smart to get a box of Lapua factory ammo and chronograph it. That will immediately give you a good idea whether you have a slow, average, or fast barrel. Then you can set your velocity goals accordingly. For example, if the factory 105gr 6BR ammo runs about 2780-2790 fps in your gun, it has an average barrel. If it runs 2820+ in a 26″ barrel (or 2835 fps in a 28″), you’ve got a fast tube.
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion.
Cartridge Efficiency: A Primer (pun intended!)by USAMU Staff
The U.S. Army Marksmanship Unit (USAMU) published a series of reloading articles on its Facebook Page. In this article, the USAMU discusses cartridge case efficiency and its benefits. While this is oriented primarily toward NRA High Power Rifle and Long Range (1000-yard) competition, these factors also apply to medium/big game hunters. Assuming one’s rifle and ammunition are accurate, key considerations include ballistic performance (i.e., resistance to wind effects, plus trajectory), recoil, and throat erosion/barrel life.
Efficient cartridges make excellent use of their available powder and case/bore capacity. They yield good ballistic performance with relatively little recoil and throat erosion. A classic example in the author’s experience involved a featherweight 7x57mm hunting/silhouette rifle. When loaded to modern-rifle pressures, just 43-44 grains of powder pushed a 139gr bullet at 2900 fps from its 22″ barrel. Recoil in this light rifle was mild; it was very easy to shoot well, and its performance was superb.
An acquaintance chose a “do everything” 7mm Remington Magnum for use on medium game at short ranges. A larger, heavier rifle, it used ~65 grains of powder to achieve ~3200 fps with similar bullets — from its 26″ barrel. Recoil was higher, and he was sensitive to it, which hampered his shooting ability.
Similarly efficient calibers include the 6mm BR [Norma], and others. Today’s highly-efficient calibers, such as 6mm BR and a host of newer developments might use 28-30 grains of powder to launch a 105-107gr match bullet at speeds approaching the .243 Winchester. The .243 Win needs 40-45 grain charges at the same velocity.
Champion-level Long Range shooters need every ballistic edge feasible. They compete at a level where 1″ more or less drift in a wind change could make the difference between winning and losing. Shooters recognized this early on — the then-new .300 H&H Magnum quickly supplanted the .30-06 at the Wimbledon winner’s circle in the early days.
The .300 Winchester Magnum became popular, but its 190-220gr bullets had their work cut out for them once the 6.5-284 and its streamlined 140-142gr bullets arrived on the scene. The 6.5-284 gives superb accuracy and wind performance with about half the recoil of the big .30 magnums – albeit it is a known barrel-burner.
Currently, the 7mm Remington Short Action Ultra-Magnum (aka 7mm RSAUM), is giving stellar accuracy with cutting-edge, ~180 grain bullets, powder charges in the mid-50 grain range and velocities about 2800+ fps in long barrels. Beyond pure efficiency, the RSAUM’s modern, “short and fat” design helps ensure fine accuracy relative to older, longer cartridge designs of similar performance.
Recent design advances are yielding bullets with here-to-fore unheard-of ballistic efficiency; depending on the cartridge, they can make or break ones decision. Ballistic coefficients (“BC” — a numerical expression of a bullet’s ballistic efficiency) are soaring to new heights, and there are many exciting new avenues to explore.
The ideal choice [involves a] balancing act between bullet BCs, case capacity, velocity, barrel life, and recoil. But, as with new-car decisions, choosing can be half the fun!
Factors to Consider When Evaluating Cartridges
For competitive shooters… pristine accuracy and ballistic performance in the wind are critical. Flat trajectory benefits the hunter who may shoot at long, unknown distances (nowadays, range-finders help). However, this is of much less importance to competitors firing at known distances.
Recoil is an issue, particularly when one fires long strings during competition, and/or multiple strings in a day. Its effects are cumulative; cartridges with medium/heavy recoil can lead to shooter fatigue, disturbance of the shooting position and lower scores.
For hunters, who may only fire a few shots a year, recoil that does not induce flinching during sight-in, practice and hunting is a deciding factor. Depending on their game and ranges, etc., they may accept more recoil than the high-volume High Power or Long Range competitor.
Likewise, throat erosion/barrel life is important to competitive shooters, who fire thousands of rounds in practice and matches, vs. the medium/big game hunter. A cartridge that performs well ballistically with great accuracy, has long barrel life and low recoil is the competitive shooter’s ideal. For the hunter, other factors may weigh more heavily.
Cartridge Efficiency and Energy — Another Perspective
Former Lapua staffer Kevin Thomas explains that efficiency can be evaluated in terms of energy:
“Cartridge efficiency is pretty straight forward — energy in vs. energy out. Most modern single-based propellants run around 178-215 ft/lbs of energy per grain. These figures give the energy potential that you’re loading into the rifle. The resulting kinetic energy transferred to the bullet will give you the efficiency of the round. Most cases operate at around 20-25% efficiency. This is just another way to evaluate the potential of a given cartridge. There’s a big difference between this and simply looking at max velocities produced by various cartridges.”
Our take on Bore-Store Gun sleeves is simple: They work great, so buy them and use them — for ALL your valuable firearms.
Winter’s here, with rain and snow in much of the country. We known readers will have their guns in the safe for long periods. For winter storage, we recommend Bore-Stores. These thick, synthetic-fleece sacks cushion your guns, preventing nicks and scratches. The breathable fabric wicks away moisture, and the fibers are coating with corrosion inhibitors. I personally use Bore-Stores for in-safe storage with all my guns, and I have never had one of my guns rust inside a Bore-Store, even when I lived a stone’s throw from the ocean and its salty air.
Bore-Stores are offered in a range of sizes to fit everything from a snub-nosed revolver to a 33″-barrelled Black Powder Rifle. Bore-Stores can be purchased for $9.99 – $28.99 from Borestores.com. For most scoped rifles, we recommend the 10″x46″ SRC-1 Case ($25.99). For a long-barreled F-Class or ELR rig you can try the 10″x52″ Scoped Shotgun Case ($28.99). Or, for guns with extremely long barrels, you can remove the scope and use the 7″x60″ MUS-1 Musket Bore-Store ($32.99) . The Bore-Store manufacturer, Big Spring Enterprises, will also craft custom sizes on request.
Triple-Layer Sealed Bags — Affordable and Effective
Consider Military-Style, Triple-Layer Bags for Long-Term Storage
While we prefer Bore-Stores for regularly-used guns, if you have heirloom firearms that will be kept in storage for very long periods without seeing any use, you may want to grease them up and place them in the thin, but rugged three-layer storage bags sold by Brownells. The bags are made from a three-layer laminate of polyester, aluminum, and polyethylene film, with a shiny silver exterior. Though the laminate is thin, the Brownells storage bags are puncture-resistant, and have a 0% moisture transmission rating so moisture can’t get inside. These bags are also resistant to petroleum-based chemicals and they won’t break down even in contact with soil or moisture.
Here’s one VITAL bit of advice for using these bags. Be absolutely sure, before you seal up the bags, that your guns are DRY and that all metal surfaces have been coated with an effective anti-corrosive, such as BoeShield T9 or Eezox. Brownells’ storage bags are inexpensive. A three-pack of 12″x 60″ rifle sacks (item 083-055-003WB) costs $22.99 — under 8 bucks a gun. That’s certainly cheap insurance for rifles and shotguns that may cost many thousands of dollars.
Get Your Guns Out of Foam-lined Cases — They Are Rust Magnets
Just about the worst thing you can do for long-term storage (short of leaving your rifle outside in the rain) is to store firearms in tight, foam-padded cases. The foam in these cases actually collects and retains moisture from the air, acting as the perfect breeding ground for rust. Even in warm summer months, humid air can leave moisture in the foam.
Remember, those plastic-shelled cases with foam interiors are for transport, not for long-term storage. Don’t repeat the mistake of a wealthy gun collector I know. He stored four valuable Colt Single Action Army (SAA) revolvers in individual foam-padded cases, and locked these away in his gun safe. A year later, every one of his precious SAAs had rusted, some badly.
If you need a good hunting rifle, consider a Tikka. The latest generation Tikka T3x rifles are very popular with hunters around the globe — for good reason. These rifles offer smooth-running actions, easy sub-MOA accuracy with good ammo, crisp triggers, and reliable detachable box magazines. The Tupperware stocks aren’t super-rigid, but they are comfortable and easy to handle. The Tikka T3 and T3x models are smart choices for hunters, offering good performance for the price (starting at $629.99 for the T3x Lite, now on sale at EuroOptic.com). Tikka’s T3x series includes a wide selection of chamberings, from .204 Ruger up to the large magnums.
Testing the T3x Series on the Range — Fun in Finland
This video was produced at a range in Finland. Tikka product manager Taneli Pokkinen shoots three Tikka rifles — the first two prone, off bipod, and the third standing (as a hunter might shoot). You can see the recoil of various chamberings, plus the accuracy at 100m, which is pretty impressive. Rifles tested are: 1) Tikka T3x Varmint Hunter; 2) Tikka T3x Super Varmint (with suppressor); 3) Tikka T3x Roughtech Ember. NOTE: At 4:30 there is a 5-shot group from the Super Varmint as shot by a gunsmith. All shots are touching — very impressive!
These two short videos explain two key features of modern Tikka rifles — the smooth running bolt and the precise, crisp, and relatively light trigger. We recommend you check out both of these tech videos if you’ve never handled a Tikka rifle before. Tikkas really do have very good factory triggers, with bolt smoothness that rivals some custom actions.
Tikka Rifles — Five Recent Models Reviewed
If you are considering a Tikka for PRS/NRL, check the first segment of this video covering the Tikka T3x TAC A1. In order, here are the five (5) Tikka rifle reviewed, with video start times (if you want to skip around): 1. Tikka T3x Super Varmint (00:40, video only); 2. Tikka T3x TAC A1 (01:13); 3. Tikka T3x Super Varmint (02:34); 4. Tikka T3x Lite Roughtech Ember (05:12); 5. Tikka T3x Varmint Hunter (wood) (07:31). Note: The review sections are done by a knowledgeable Tikka product manager Taneli Pokkinen. CLICK HERE for 40+ Tikka factory videos.
Tikka T3X — Hickok45 Shows Function and Shoots at Steel Plates
Popular YouTube gun reviewer Hickok45 reviews the Tikka T3x Tactical Compact Rifle in 6.5 Creedmoor. There are good explanations of the operation of the action and magazine. In addition Hickok45 shoots the rifle offhand (05:10 and 13:44 time-marks), evaluating the ergonomics of the stock and the trigger feel. Hickok45 now has 7.98 million subscribers to his YouTube Channel.
Tikka T3x Compact Lite Roughtech Ember
The Tikka Compact Lite Roughtech Ember has a handsome brown polymer stock with subtle camo. This nicely-finished 6.8-pound rifle comes with a stainless fluted barrel fitted with factory muzzle brake. It is on sale currently starting at $939.99 at EuroOptic.com. The stock has interchangeable pistol grips for various shooting positions. The fore-grip has attachment points, allowing forearm width to be increased. In this video, at the 8:40 time-mark, the trigger is adjusted to crisp 2.5 pounds, as verified with a trigger gauge. That is excellent for a factory trigger.
Why the TIKKa T3x Is Great for Hunting
With 970,000+ subscribers, the Backfire Channel is one of the most popular gun channels on YouTube. You can trust Backfire reviewers because they pay their own money for all the products they review. This video reviews current generation Tikka rifles. Backfire had high praise for Tikka T3x rifles: “The Tikka T3x SL is an incredibly lightweight mountain rifle that should be in every hunter’s safe. We like it for its lightweight build, stainless steel barrel, superb trigger, and surprisingly accurate shooting. Overall, this is the hunting rifle we recommend more frequently than any other.”
TIKKA T3x TAC A1
Along with the hunting rifle models, Tikka also produces quality, metal chassis tactical-style rifles. The Tikka T3x TAC A1 has earned considerable praise and is PRS/NRL competition-ready right out of the box. The T3x TAC A1 is offered in multiple calibers/chamberings, barrel lengths, and chassis colors. The impressive T3x TAC A1 retails for $1999.00 – $2319.00 at EuroOptic.com.
BONUS: TIKKA T3x vs. Ruger American
This comparison video compares the Tikka T3x with the Ruger American rifle. The reviewers explain the key differences and the pros and cons of each type. The video examines the receivers, barrels, triggers, and stocks of the Tikka and the Ruger. What’s the bottom line? Well the Ruger has a price advantage, but the Tikka T3x has a better trigger, nicer action, better magazines, and probably better 5-shot accuracy.
Let’s face it, AR-platform rifles run dirty, at least compared to typical bolt-action rifles. The AR-15 works by piping gas from the barrel back into the bolt carrier, causing the bolt to unlock and the carrier to move the bolt backward. The “exhaust gas” from the barrel contains soot and carbon. The carbon will form hard deposits on the bolt. In addition, the carbon can combine with lube on the bolt carrier to make a nasty, paste-like sludge. This can be particularly problematic when the black paste pollutes the ejector and extractor recess.
This Editor has inspected dozens of ARs over the years. Other than mag-related malfunctions, the most common cause of AR cycling problems I found was oily gunk in the extractor and ejector areas. Many AR owners overlook these critical areas. Look at an AR that hasn’t been cleaned properly and you’ll probably find black gunk (and small brass shavings) in the ejector and extractor recesses.
If you want to keep your black rifle running smoothly and reliably, you must clean it regularly and follow the correct maintenance procedures. Here are three videos that explain how to properly disassemble and clean AR-platform rifles. And then they cover the essential lubrication ARs need to run reliably.
Take-Down and Full Cleaning of AR15 by Jerry Miculek
Here ace shooter Jerry Miculek takes down and cleans an AR-platform rifle belonging to his daughter Lena. This is a good video because Lena’s rifle was “run hard and packed up dirty” so you can see where carbon and grease build up. This 35-minute video is very thorough. Jerry is one of the nation’s top action carbine shooters, so listen carefully to his advice on cleaning and lubrication.
General AR-15 Maintenance and Lubrication
There are various schools of thought on AR lubrication. Some guys like to run “wet” with lots of CLP, while others choose to focus lubrication on the key spots that receive the most friction and wear, such as the contact point for the bolt carrier. We do advice check the ejector recess and extractor spring recess frequently as gunk can get in there, causing malfunctions. Here is a good video from Pew Pew Tactical — a 7-minute guide to cleaning and lubricating AR-platform rifles. This shows important details for both the upper and the lower.
How to Clean Your AR-15 Bolt Carrier Assembly
This video offers very specific advice on the bolt carrier group, which receives the dirty gas directly from the barrel. Be sure to check the extractor and ejector recesses. That’s where old lube, brass shavings, and carbon accumulate. Follow the directions in this video for lubrication, and don’t over-lubricate the bolt carrier — that will only capture more carbon.
All shooters, even rimfire enthusiasts, should always wear ear protection when at the range. A typical rifle gunshot is very loud — in the region of 140 to 170 decibels (the pain threshold is 130-140 db). Without ear protection, you can permanently damage your hearing during a single shooting session. We all know older shooters who are partially deaf, or who suffer from Tinnitus, because they didn’t use earplugs or muffs when they were younger.
How Humans Hear Sounds — Amazing Video Reveals All
The human sense of hearing involves multiple delicate internal membranes, bones, organs, and nerves. Shooters understand the importance of protecting their hearing, but they may not understand the bio-mechanics of human hearing. We hear sounds through Auditory Transduction. Sound waves vibrate the ear drum (tympanic membrane), but that is only the beginning. These vibrations are passed along via tiny rocker-arm-like bones to be “processed” in a spiral chamber, the cochlea.
This remarkable VIDEO explains how humans hear sounds. We strongly recommend you take the time to watch and learn. The hearing you save may be your own!
Click Speaker Icon to turn on the video’s soundtrack.
Vibrations moving through the cochlea are separated into frequencies and then sent as neural messages to the brain. It is an astonishingly complex process, one that truly seems miraculous when you examine the bio-engineering involved. In the Video above, the process of human Auditory Transduction is explained and illustrated with 3D animation. You really should watch this amazing video. By the end you will have a new-found appreciation for your ability to hear.
Every shooter should own a pair of Electronic muffs, even if you prefer shooting with earplugs and/or standard muffs. Electronic muffs are great when you are spotting for other shooters or are working near the firing line. They let you hear ordinary conversations while still providing vital hearing protection. You can also wear ear-plugs under muffs for extra sound attenuation.
Plugs PLUS Ear-Muffs — The Benefits of “Doubling-Up” Your Hearing Protection
According to OHS Online: “The combined attenuation of an ear plug and an ear muff is not simply the algebraic sum of the performance of each individual protector. This is due to an acoustic and vibratory interaction between the ear muff and the ear plug that causes them to behave together as a system rather than as independent hearing protectors.
Generally speaking, when you combine two hearing protectors, ear muffs over ear plugs, you can expect an increase [in noise reduction] of between 3 and 10 dB over the higher-performing hearing protector. OSHA [now advises] 5 dB as the [typical] benefit offered by combining hearing protectors.” Source: OHSonline.com