Sinclair Internationalhas released an interesting article about Case Concentricity* and bullet “run-out”. This instructional article by Bob Kohl explains the reasons brass can exhibit poor concentricity, and why high bullet run-out can be detrimental to accuracy.
Concentricity, Bullet Alignment, and Accuracyby Bob Kohl
The purpose of loading your own ammo is to minimize all the variables that can affect accuracy and can be controlled with proper and conscientious handloading. Concentricity and bullet run-out are important when you’re loading for accuracy. Ideally, it’s important to strive to make each round the same as the one before it and the one after it. It’s a simple issue of uniformity.
The reason shooters work with tools and gauges to measure and control concentricity is simple: to make sure the bullet starts down the bore consistently in line with the bore. If the case isn’t properly concentric and the bullet isn’t properly aligned down the center of the bore, the bullet will enter the rifling inconsistently. While the bore might force the bullet to align itself with the bore (but normally it doesn’t), the bullet may be damaged or overstressed in the process – if it even it corrects itself in transit. These are issues we strive to remedy by handloading, to maintain the best standard possible for accurate ammunition.
The term “concentricity” is derived from “concentric circle”. In simple terms it’s the issue of having the outside of the cartridge in a concentric circle around the center. That goes from case head and center of the flash hole, to the tip of the bullet.
Factors Affecting Concentricity
The point of using this term is to identify a series of issues that affect accurate ammunition. Ideally this would work best with a straight-walled case; but since most rifle cartridge cases are tapered, it equates to the smallest cross section that can be measured point by point to verify the concentric circle around the center. For the examples below, I’m working with .308 Winchester ammo.
Figure 1: The cartridge.
Figure 2: Centerline axis of the case, extending from flash hole to case mouth.
The case walls have to be in perfect alignment with the center, or axis, of that case, even if it’s measured at a thousandth of an inch per segment (in a tapered case).
Figure 3: Case body in alignment with its axis, or centerline, even in a tapered case.
The case neck must also be in alignment with its axis. By not doing so you can have erratic bullet entry into the bore. The case neck wall itself should be as uniform as possible in alignment and in thickness (see the M80 7.62x51mm NATO cartridge in Figure 5) and brass can change its alignment and shape. It’s why we expand the case neck or while some folks ream the inside of the neck and then turn the outside for consistent thickness, which affects the tension on the bullet when seated.
Figure 4: Neck in alignment with center of the case axis.
Figure 5: Variations in case neck wall thickness, especially on some military brass, can cause an offset of the bullet in its alignment. This is an M80 ball round. Note the distinct difference of the neck walls.
Having a ball micrometer on hand helps, especially with military brass like 7.62x51mm in a semi-auto rifle, where there are limits as to how thin you want the neck walls to be. In the case of 7.62 ball brass you want to keep the wall to .0145″.
Figure 6: A ball micrometer like this RCBS tool (#100-010-268) can measure case neck thickness.
Turning the outside of the neck wall is important with .308 military cases regardless of whether you expand or ream the neck walls. There are several outside neck turning tools from Forster, Hornady, Sinclair, and others. I’ve been using classic Forster case trimming (#100-203-301) and neck turning (#749-012-890) tools for 40 years.
Bullet Run-Out
The cartridge, after being loaded, still needs to be in alignment with the center of the case axis. Figure 7 shows a bad example of this, a round of M80 ball. A tilted bullet is measured for what’s known as bullet “run-out”.
Figure 7: An M80 round with the bullet tilted and not aligned with the axis. This will be a flyer!
Run-out can be affected by several things: (1) improperly indexing your case while sizing, which includes not using the proper shell holder, especially while using a normal expander ball on the sizing die (it also can stretch the brass). (2) The head of a turret press can flex; and (3) improper or sloppy bullet seating. This is also relevant when it comes to using a progressive press when trying to load accuracy ammo.
Mid Tompkins came up with a simple solution for better bullet seating years ago. Seat your bullet half way into the case, back off the seater die and rotate the case 180 degrees before you finish seating the bullet. It cuts down on run-out problems, especially with military brass. You also want to gently ream the inside of the neck mouth to keep from having any brass mar the surface of the bullet jacket and make proper seating easier. A tilted bullet often means a flyer.
Figure 8: Proper alignment from the center of the case head to the tip of the bullet.
(NOTE: This links to a Web Archive version of the original Sinclair Int’l article.)
*Actually some folks would say that if we are talking about things being off-center or out-of-round, we are actually talking about “eccentricity”. But the tools we use are called “Concentricity Gauges” and Concentricity is the term most commonly used when discussing this subject.
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Sinclair Internationalhas released an interesting article about Case Concentricity* and bullet “run-out”. This instructional article by Bob Kohl explains the reasons brass can exhibit poor concentricity, and why high bullet run-out can be detrimental to accuracy.
Concentricity, Bullet Alignment, and Accuracyby Bob Kohl
The purpose of loading your own ammo is to minimize all the variables that can affect accuracy and can be controlled with proper and conscientious handloading. Concentricity and bullet run-out are important when you’re loading for accuracy. Ideally, it’s important to strive to make each round the same as the one before it and the one after it. It’s a simple issue of uniformity.
The reason shooters work with tools and gauges to measure and control concentricity is simple: to make sure the bullet starts down the bore consistently in line with the bore. If the case isn’t properly concentric and the bullet isn’t properly aligned down the center of the bore, the bullet will enter the rifling inconsistently. While the bore might force the bullet to align itself with the bore (but normally it doesn’t), the bullet may be damaged or overstressed in the process – if it even it corrects itself in transit. These are issues we strive to remedy by handloading, to maintain the best standard possible for accurate ammunition.
The term “concentricity” is derived from “concentric circle”. In simple terms it’s the issue of having the outside of the cartridge in a concentric circle around the center. That goes from case head and center of the flash hole, to the tip of the bullet.
Factors Affecting Concentricity
The point of using this term is to identify a series of issues that affect accurate ammunition. Ideally this would work best with a straight-walled case; but since most rifle cartridge cases are tapered, it equates to the smallest cross section that can be measured point by point to verify the concentric circle around the center. For the examples below, I’m working with .308 Winchester ammo.
Figure 1: The cartridge.
Figure 2: Centerline axis of the case, extending from flash hole to case mouth.
The case walls have to be in perfect alignment with the center, or axis, of that case, even if it’s measured at a thousandth of an inch per segment (in a tapered case).
Figure 3: Case body in alignment with its axis, or centerline, even in a tapered case.
The case neck must also be in alignment with its axis. By not doing so you can have erratic bullet entry into the bore. The case neck wall itself should be as uniform as possible in alignment and in thickness (see the M80 7.62x51mm NATO cartridge in Figure 5) and brass can change its alignment and shape. It’s why we expand the case neck or while some folks ream the inside of the neck and then turn the outside for consistent thickness, which affects the tension on the bullet when seated.
Figure 4: Neck in alignment with center of the case axis.
Figure 5: Variations in case neck wall thickness, especially on some military brass, can cause an offset of the bullet in its alignment. This is an M80 ball round. Note the distinct difference of the neck walls.
Having a ball micrometer on hand helps, especially with military brass like 7.62x51mm in a semi-auto rifle, where there are limits as to how thin you want the neck walls to be. In the case of 7.62 ball brass you want to keep the wall to .0145″.
Figure 6: A ball micrometer like this RCBS tool (#100-010-268) can measure case neck thickness.
Turning the outside of the neck wall is important with .308 military cases regardless of whether you expand or ream the neck walls. There are several outside neck turning tools from Forster, Hornady, Sinclair, and others. I’ve been using classic Forster case trimming (#100-203-301) and neck turning (#749-012-890) tools for 40 years.
Bullet Run-Out
The cartridge, after being loaded, still needs to be in alignment with the center of the case axis. Figure 7 shows a bad example of this, a round of M80 ball. A tilted bullet is measured for what’s known as bullet “run-out”.
Figure 7: An M80 round with the bullet tilted and not aligned with the axis. This will be a flyer!
Run-out can be affected by several things: (1) improperly indexing your case while sizing, which includes not using the proper shell holder, especially while using a normal expander ball on the sizing die (it also can stretch the brass). (2) The head of a turret press can flex; and (3) improper or sloppy bullet seating. This is also relevant when it comes to using a progressive press when trying to load accuracy ammo.
Mid Tompkins came up with a simple solution for better bullet seating years ago. Seat your bullet half way into the case, back off the seater die and rotate the case 180 degrees before you finish seating the bullet. It cuts down on run-out problems, especially with military brass. You also want to gently ream the inside of the neck mouth to keep from having any brass mar the surface of the bullet jacket and make proper seating easier. A tilted bullet often means a flyer.
Figure 8: Proper alignment from the center of the case head to the tip of the bullet.
(NOTE: This links to a Web Archive version of the original Sinclair Int’l article.)
*Actually some folks would say that if we are talking about things being off-center or out-of-round, we are actually talking about “eccentricity”. But the tools we use are called “Concentricity Gauges” and Concentricity is the term most commonly used when discussing this subject.
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Here’s a helpful hint for hand-loaders from Sierra Bullets. While this article focuses on Sierra’s new Tipped Match-King bullets, the recommended solutions apply to other bullet types as well. The article explains how sharp edges on a seating stem can cause a ring to be pressed into the bullet jacket — especially with compressed loads that resist downward bullet movement. Here Sierra technician Rich Machholz diagnoses the problem and provides a solution.
Solutions for Ring Marks Caused by Seating Stems
by Sierra Bullets Ballistic Technician Rich Machholz
Now that the new Tipped MatchKing® (TMK) bullets are being shipped and shooters are putting them to use I have received several calls regarding marking on the bullet ogive from the seating stem.
The cause can be traced to one of several things. In the .223 and especially with the long, 77 grain TMK seated at 2.250” or even 2.260” most loads of Varget® and Reloder® 15 are compressed loads, sometimes heavily compressed. This puts a great deal of pressure on the bullet through the seating stem. The result of all this pressure is a mark of varying depth and appearance on the ogive of the bullet. [Editor: We have seen this issue with a variety of other bullet types/shapes as well, including non-tipped VLDs. The solution is profiling the internal cone of the seating stem to match your bullet shape.]
Some older seating stems might even bear against the tip of the bullet which can make a slight bulge in the jacket just below the junction of the resin tip and the copper jacket in a compressed load. If this is the case there is not a ready fix other than calling the die manufacturer and requesting a new deeper seating stem.
Polish Your Seating Stem to Remove Sharp Internal Edges
If the seating stem is of proper depth the culprit most generally is a thin sharp edge on the inside taper of the seating stem. This is an easy fix that can be accomplished by chucking a spare 77 grain bullet in your drill, coating it with valve grinding compound or even rubbing compound or in a pinch even tooth paste.* Remove the seating stem assembly from the seating die. Turn the drill on and put the seating stem recess over the spinning bullet with the polishing compound to break or smooth the sharp edge that is making the offending mark. This might take more than one application to get the proper polish depending upon what you use, but the more you polish the better the blend of angles which will [ensure the stem matches the bullet contours, not leaving a sharp ring].
If the above is a little more than you care to tackle you might try very fine emery cloth twisted to a point that can be inserted into the mouth to the seating stem and rotated to polish the inside to eliminate any sharp edges that might be present.
Load Advice for 77gr TMKs in the .223 Rem
And last but certainly not least. Actually, even though we don’t say you need additional data for the TMKs, remember you are dealing with heavily-compressed loads in some cases because of the additional bullet length. Due to the additional length of these new bullets and in the interest of gaining some room in the case you might consider trying a slightly faster extruded powder like BenchMark or the 4895s or an even more dense powder like the spherical H335®, CFE223 or TAC. The extra room will allow for trouble free bullet seating also.
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Did you know that there’s a free online resource that provides key data for thousands of bullet designs? The ShootForum Bullet Database provides profiles with weight, length, SD, and Ballistic Coefficient for nearly 3900 bullet types from all the major manufacturers. You can access all this info for free. This is a great place to start when you’re considering bullet options for a new rifle, or a new chambering for an existing rifle. To be fair, not all the latest, greatest match bullets are listed here. Could the database benefit from updates — yes, but it is still a great info source. You should definitely bookmark this resource for easy access in the future.
The massive ShootForum.com Bullet Database includes over 3900 bullet designs in all. We counted nearly 200 different 6mm bullets! The bullet info comes from the makers of QuickLOAD Software. Access to the online database is FREE. Most database entries include Caliber, Manufacturer, Stated Bullet Weight, True Bullet Weight, Length, Sectional Density (SD), and Ballistic Coefficient. In many cases multiple BCs are provided for different velocity ranges. Having bullet length lets you know right away if your cartridge/bullet combo can fit your magazine.
The database is great if you’re looking for an unusual caliber, or you want a non-standard bullet diameter to fit a barrel that is tighter or looser than spec. You’ll find the popular jacketed bullets from major makers, plus solids, plated bullets, and even cast bullets. For those who don’t already own QuickLOAD software, this is a great resource, providing access to a wealth of bullet information.
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Sinclair Internationalhas released an interesting article about Case Concentricity* and bullet “run-out”. This instructional article by Bob Kohl explains the reasons brass can exhibit poor concentricity, and why high bullet run-out can be detrimental to accuracy.
Concentricity, Bullet Alignment, and Accuracyby Bob Kohl
The purpose of loading your own ammo is to minimize all the variables that can affect accuracy and can be controlled with proper and conscientious handloading. Concentricity and bullet run-out are important when you’re loading for accuracy. Ideally, it’s important to strive to make each round the same as the one before it and the one after it. It’s a simple issue of uniformity.
The reason shooters work with tools and gauges to measure and control concentricity is simple: to make sure the bullet starts down the bore consistently in line with the bore. If the case isn’t properly concentric and the bullet isn’t properly aligned down the center of the bore, the bullet will enter the rifling inconsistently. While the bore might force the bullet to align itself with the bore (but normally it doesn’t), the bullet may be damaged or overstressed in the process – if it even it corrects itself in transit. These are issues we strive to remedy by handloading, to maintain the best standard possible for accurate ammunition.
The term “concentricity” is derived from “concentric circle”. In simple terms it’s the issue of having the outside of the cartridge in a concentric circle around the center. That goes from case head and center of the flash hole, to the tip of the bullet.
Factors Affecting Concentricity
The point of using this term is to identify a series of issues that affect accurate ammunition. Ideally this would work best with a straight-walled case; but since most rifle cartridge cases are tapered, it equates to the smallest cross section that can be measured point by point to verify the concentric circle around the center. For the examples below, I’m working with .308 Winchester ammo.
Figure 1: The cartridge.
Figure 2: Centerline axis of the case, extending from flash hole to case mouth.
The case walls have to be in perfect alignment with the center, or axis, of that case, even if it’s measured at a thousandth of an inch per segment (in a tapered case).
Figure 3: Case body in alignment with its axis, or centerline, even in a tapered case.
The case neck must also be in alignment with its axis. By not doing so you can have erratic bullet entry into the bore. The case neck wall itself should be as uniform as possible in alignment and in thickness (see the M80 7.62x51mm NATO cartridge in Figure 5) and brass can change its alignment and shape. It’s why we expand the case neck or while some folks ream the inside of the neck and then turn the outside for consistent thickness, which affects the tension on the bullet when seated.
Figure 4: Neck in alignment with center of the case axis.
Figure 5: Variations in case neck wall thickness, especially on some military brass, can cause an offset of the bullet in its alignment. This is an M80 ball round. Note the distinct difference of the neck walls.
Having a ball micrometer on hand helps, especially with military brass like 7.62x51mm in a semi-auto rifle, where there are limits as to how thin you want the neck walls to be. In the case of 7.62 ball brass you want to keep the wall to .0145″.
Figure 6: A ball micrometer like this RCBS tool (#100-010-268) can measure case neck thickness.
Turning the outside of the neck wall is important with .308 military cases regardless of whether you expand or ream the neck walls. There are several outside neck turning tools from Forster, Hornady, Sinclair, and others. I’ve been using classic Forster case trimming (#100-203-301) and neck turning (#749-012-890) tools for 40 years.
Bullet Run-Out
The cartridge, after being loaded, still needs to be in alignment with the center of the case axis. Figure 7 shows a bad example of this, a round of M80 ball. A tilted bullet is measured for what’s known as bullet “run-out”.
Figure 7: An M80 round with the bullet tilted and not aligned with the axis. This will be a flyer!
Run-out can be affected by several things: (1) improperly indexing your case while sizing, which includes not using the proper shell holder, especially while using a normal expander ball on the sizing die (it also can stretch the brass). (2) The head of a turret press can flex; and (3) improper or sloppy bullet seating. This is also relevant when it comes to using a progressive press when trying to load accuracy ammo.
Mid Tompkins came up with a simple solution for better bullet seating years ago. Seat your bullet half way into the case, back off the seater die and rotate the case 180 degrees before you finish seating the bullet. It cuts down on run-out problems, especially with military brass. You also want to gently ream the inside of the neck mouth to keep from having any brass mar the surface of the bullet jacket and make proper seating easier. A tilted bullet often means a flyer.
Figure 8: Proper alignment from the center of the case head to the tip of the bullet.
(NOTE: This links to a Web Archive version of older Sinclair Int’l article.)
*Actually some folks would say that if we are talking about things being off-center or out-of-round, we are actually talking about “eccentricity”. But the tools we use are called “Concentricity Gauges” and Concentricity is the term most commonly used when discussing this subject.
Story Tip from EdLongrange. We welcome reader submissions.
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Photo 1: Three Near-Equal-Weight 7mm Bullets with Different Shapes
TECH TIP: Bullets of the same weight (and caliber) can generate very different pressure levels due to variances in Bearing Surface Length (BSL).
Bullet 1 (L-R), the RN/FB, has a very slight taper and only reaches its full diameter (0.284″) very near the cannelure. This taper is often seen on similar bullets — it helps reduce pressures with good accuracy. The calculated BSL of Bullet 1 was ~0.324″. The BSL of Bullet 2, in the center, was ~0.430”, and Bullet 3’s was ~ 0.463″. Obviously, bullets can be visually deceiving as to BSL!
This article from the USAMU covers an important safety issue — why you should never assume that a “book” load for a particular bullet will be safe with an equal-weight bullet of different shape/design. The shape and bearing surface of the bullet will affect the pressure generated inside the barrel. This is part of the USAMU’s Handloading Hump Day series, published on the USAMU Facebook page.
Beginning Handloading, Part 13:
Extrapolating Beyond Your Data, or … “I Don’t Know, What I Don’t Know!”
We continue our Handloading Safety theme, focusing on not inadvertently exceeding the boundaries of known, safe data. Bullet manufacturers’ loading manuals often display three, four, or more similar-weight bullets grouped together with one set of load recipes. The manufacturer has tested these bullets and developed safe data for that group. However, seeing data in this format can tempt loaders — especially new ones — to think that ALL bullets of a given weight and caliber can interchangeably use the same load data. Actually, not so much.
The researchers ensure their data is safe with the bullet yielding the highest pressure. Thus, all others in that group should produce equal or less pressure, and they are safe using this data.
However, bullet designs include many variables such as different bearing surface lengths, hardness, and even slight variations in diameter. These can occasionally range up to 0.001″ by design. Thus, choosing untested bullets of the same weight and caliber, and using them with data not developed for them can yield excess pressures.
This is only one of the countless reasons not to begin at or very near the highest pressure loads during load development. Always begin at the starting load and look for pressure signs as one increases powder charges.
Bullet bearing surface length (BSL) is often overlooked when considering maximum safe powder charges and pressures. In photo 1 (at top), note the differences in the bullets’ appearance. All three are 7mm, and their maximum weight difference is just five grains. Yet, the traditional round nose, flat base design on the left appears to have much more BSL than the sleeker match bullets. All things being equal, based on appearance, the RN/FB bullet seems likely to reach maximum pressure with significantly less powder than the other two designs.
Bearing Surface Measurement Considerations
Some might be tempted to use a bullet ogive comparator (or two) to measure bullets’ true BSL for comparison’s sake. Unfortunately, comparators don’t typically measure maximum bullet diameter and this approach can be deceiving.
Photo 2: The Perils of Measuring Bearing Surface Length with Comparators
In Photo 2, two 7mm comparators have been installed on a dial caliper in an attempt to measure BSL. Using this approach, the BSLs differed sharply from the original [measurements]. The comparator-measured Bullet 1 BSL was 0.694” vs. 0.324” (original), Bullet 2 was 0.601” (comparator) vs. 0.430” (original), and Bullet 3 (shown in Photo 2) was 0.602” (comparator) vs. 0.463” (original). [Editor’s comment — Note the very large difference for Bullet 1, masking the fact that the true full diameter on this bullet starts very far back.]
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Here’s a very cool 3D Animation showing pistol rounds being fired. Computer-generated graphics provide a look inside the cartridge at the moment of ignition as the primer fires and the flame front moves through the ignited powder. It’s really kind of mesmerizing. If you’ve every wondered just what happens inside your cartridges the moment that firing pin strikes, then watch this video…
Watch Video to See Handgun Ammo Being Chambered and Fired:
Mute Enabled — Click Speaker Icon to Hear Audio. Firing Sequence Starts at 1:28.
This animated video from German ammo-maker GECO (part of the Swiss RUAG group of companies) reveals the inside of a pistol cartridge, showing jacket, lead core, case, powder and primer. Employing advanced 3D rendering and computer graphics, the video shows an X-ray view of ammo being loaded in a handgun, feeding from a magazine.
Then it really gets interesting. At 1:28 – 1:50 you’ll see the firing pin strike the primer cup, the primer’s hot jet streaming through the flash-hole, and the powder igniting. Finally you can see the bullet as it moves down the barrel and spins its way to a target. This is a very nicely-produced video. If you’ve ever wondered what happens inside a cartridge when you pull the trigger, this video shows all. They say “a picture’s worth a thousand words”… well a 3D video is even better.
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This article, which originally appeared in the Sierra Bullets Blog, provides a new terminology that helps describe the geometry of bullets. Once you understand the meaning of “Caliber(s) of Ogive”, you can quickly evaluate potential bullet performance by comparing listed Caliber of Ogive numeric values.
by Mark Walker, Sierra Bullets New Product Development Manager
During one of our recent product releases, we listed the “caliber of ogive” of the bullet in the product description. While some understood what that number meant, it appears that some are not aware of what the number is and why it is important. In a nutshell, the “caliber of ogive” number will tell you how sleek the front end of the bullet is. The higher the number is, the sleeker the bullet. It also makes it easy to compare the ogives of different caliber bullets. If you want to know if a certain .308 caliber bullet is sleeker than a 7mm bullet, simply compare their “caliber of ogive” numbers.
So exactly how do you figure “caliber of ogive”? If you look at the drawing of the .30 caliber 175 gr HPBT bullet #2275 (at top), you will see that the actual radius of the ogive is 2.240. If you take that 2.240 ogive radius and divide by the diameter (or caliber) of the bullet you would get 7.27 “calibers of ogive” (2.240 ÷ .308 = 7.27). (See top photo).
In a nutshell, the “caliber of ogive” number will tell you how sleek the front end of the bullet is. The higher the number is, the sleeker the bullet.
Next let’s look at the print (below) of our 6.5mm 142gr HPBT #1742 bullet for comparison. The actual radius of the ogive is 2.756. Like with the .30 caliber 175 gr HPBT bullet #2275, if you divide 2.756 by the diameter (or caliber) of the bullet you get 10.44 “calibers of ogive”.
Some people would say why not just compare the actual ogive radius dimensions instead of using the “caliber of ogive” figure. If we were comparing only bullets of the exact same diameter, then that would be a reasonable thought process. However, that idea falls apart when you start trying to compare the ogives of bullets of different diameters. As you can see with the two bullets presented above, if we compare the actual ogive radius dimensions of both bullets the difference is not much at all.
However, once again, testing has shown that the 6.5mm 142 gr HPBT #1742 has a significantly higher BC. The only way that this significant increase shows up, other than when we fire the bullets in testing, is by comparing the “caliber of ogive” measurement from both bullets.
Hopefully this will help explain what we mean when we talk about “caliber of ogive” and why it’s a handy number to use when comparing bullets. This information will help you to make an informed decision the next time you are in the market to buy bullets.
Story tip from Grant Ubl. We welcome reader submissions.
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Shoot 101 Quiz
How much of an expert are you when it comes to firearms and ballistics? Test your knowledge with this interactive test. Vista Outdoors (formerly ATK Sporting Group) has launched a new multi-platform media campaign called Shoot 101, which provides “how to” information about shooting, optics, and outdoor gear.
On the Shoot 101 website, you’ll find a Ballistics Quiz. The questions are pretty basic, but it’s still fun to see if you get all the answers correct.
You don’t need a lot of technical knowledge. Roughly a third of the questions are about projectile types and bullet construction. Note, for some reason the layout doesn’t show all the possible answers at first. So, for each question, be sure to scroll down using the blue scroll bar on the right.
This custom war wagon hauls varmint hunters around the Longmeadow Game Resort in Colorado.
If you’re planning a spring Prairie Dog adventure, it’s time to load up a big supply of ammo. On a 4-day varmint safari you can easily shoot 800 rounds or more in a prime P-Dog location. To save on ammo costs for high-volume shooting, it makes sense to buy components in bulk. Here’s a super deal on bullets for your .224-caliber varmint rig.
Right now Midsouth Shooters’ Supply is running a special on Varmint Nightmare XTreme Bullets. Available in both hollow point (HP) and lead-tip soft point (SP) styles, you can get these bullets for under $50.00 for 500. The .224 55gr Flat Base Soft Point variety is on sale this week for just $42.92 for 500 bullets (that works out to just $8.58 per hundred). We’ve loaded these in .223 Rem, 22 Dasher, and 22-250 cartridges and they worked well (considering the really low price).
Powder Suggestion for High-Volume Varmint Loads
For high-shot-count varmint safaris, you want a clean-burning powder that minimizes barrel fouling. While there are many great powders for the .223 Rem, we like Hodgdon CFE 223 for our high-volume varmint loads. This powder really seems to keep barrels cleaner. Originally developed for U.S. rapid-fire military systems, CFE 223 incorporates a proprietary chemistry named “Copper Fouling Eraser”. Based on tests with extended shot strings, Hodgdon claims that, by using CFE™223, match shooters, varmint hunters, and AR shooters can maintain accuracy for longer periods, with less barrel-cleaning time. You may want to check it out.
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This an older video from the YouTube archives but we expect many readers have still not seen it yet. It definitely teaches an important lesson — never underestimate the destructive power of rifle-launched projectiles. What appears a “safe distance” from steel may actually be well within the danger zone.
In this video a rather ignorant (yet lucky) fellow demonstrates what NOT to do with a large-caliber rifle (a 50 BMG apparently). He shoots at a steel target about 70 yards away and a bullet fragment comes back directly at him. He was lucky enough that the ricochet just smacked his left ear muff. Another inch to the right and he could have lost his eye… or worse.
If you have ever done much action pistol shooting at close range on steel targets, you’ll know about the hazards of ricochets and bullet splashback. That’s why you should only shoot low-velocity rounds with soft lead or frangible bullets when shooting at relatively close range.
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At SHOT Show 2017, Nosler showcased a new .22-caliber cartridge designed for AR-platform rifles. Called the 22 Nosler, the new cartridge resembles a 6.8 SPC necked down to .22 caliber. Comparing Nosler’s ammo specs with Hodgdon load data, it looks like the 22 Nosler can deliver about 250-300 fps more velocity than the standard .223 Rem cartridge. That’s significant for varminters looking for higher performance from an AR15-type rifle. With a 55-grain bullet, highest possible velocity is 3500+ fps with a max load of Hodgdon CFE 223 powder, based on this Nosler Load Chart:
Nosler will produce 22 Nosler ammunition in various bullet weights, starting with 55 grain and 77 grain. To run the 22 Nosler, an AR owner will need a new upper and 6.8 SPC type magazines. This video explains how to convert your AR-platform rifle to run the 22 Nosler.
“Everything Old Is New Again…”
Examining the 22 Nosler cartridge, our friend Grant Ubl had a case of “deja vu”. He thinks the new 22 Nosler bears a striking resemblance to a wildcat from the 1960s: “The .22 Nosler looks like a throwback to the 1963-vintage .224 Winchester E5 experimental cartridge, right down to the rebated rim.” Here is an old Winchester print:
Another poster said this cartridge resembles the “.220 Thunderbolt” a wildcat devised by John Scandale in 2004. Posting on Facebook, Mr. Scandale said the designs were very similar. According to Keystone Accuracy, the .220 Thunderbolt’s “design origin came from the now largely popular 6mm Hagar in its infancy stage back in 2003.” While it looks very similar to a 6.8 SPC necked to .224, the .220 Thunderbolt is different because the 6mm Hagar brass is 0.100″ longer than 6.8 SPC. Read History of .220 Thunderbolt.
Neck-up the 22 Nosler to .25 Caliber?
Dan Z. has inspected in the 22 Nosler ammunition and he’d like to see a .25 Caliber version. On Facebook, Dan posted: “I got my hands on some of the ammo a couple weeks ago. It does look like a .223 that has its body diameter expanded to that of a 6.8. Consequently, it is longer than the 6.8 overall and in the body. I necked a piece of fired brass to 6.8 and it looked like it would provide some improvement in velocity. A more interesting idea might be to neck it to .25 as a .250 Savage performance clone in an AR-15 platform.”
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Sinclair International has released an interesting article about Case Concentricity* and bullet “run-out”. This instructional article by Bob Kohl explains the reasons brass can exhibit poor concentricity, and why high bullet run-out can be detrimental to accuracy.
This animated video from German ammo-maker 
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