Doug Koenig’s Championship Season returns to the Pursuit Channel for its ninth season. On this week’s episode, Koenig shoots the Zombies in the Heartland multi-gun match in Nebraska. Sponsored by Hornady, the Zombies Match is one of the biggest 3-gun matches in the nation. Later in the episode Koenig visits Hornady’s bullet-making factory in Nebraska.
Doug Koenig’s Championship Season airs on the Pursuit Channel three times each week. NOTE: If you don’t have cable, you can view shows online on your computer or mobile device at Pursuituptv.com. Weekly Cable TV broadcast times are:
Wednesday at 5:30 pm (EST) | Friday at 9:00 pm (EST) | Saturday at 1:00 am (EST)
Koenig Competes in Zombies Match in Nebraska
Teaming up with Jason Hornady and his son, Doug travels to Nebraska to shoot the popular annual 3-Gun Zombies in the Heartland match. Using pistol, rifle, and shotgun, Doug’s team shoots the Open Division Industry Match and runs six challenging stages using zombie-themed props.
This “Pandemic” 3-Gun fun match, one of the biggest three-gun shoots in the nation, takes place each summer at the Heartland Public Shooting Park in Grand Island, Nebraska. The Pandemic features a rich prize table worth over $150,000. Prizes include pistols, rifles, shotguns, scopes, AR uppers, gun parts, and gear of all kinds.
See A-Tip Bullets Crafted at Hornady Factory
In the second part of the episode, Doug visits the Hornady production facility to see how the new, sequentially-packaged A-Tip match bullets are made. These feature a very uniform aluminum tip for consistent BCs. Doug views 6mm 110 grain A-Tips as they roll off the manufacturing line. Doug plans to use this 6mm bullet in his future PRS competitions.
Do you own a black rifle? Looking to get a good supply of quality ammo and magazines for your AR? Or maybe you want to add an AR to your arsenal before the gun grabbers pass more restrictive legislation? Here are two great pre-Black Friday Deals at Palmetto State Armory. Get a complete AR Lower for just $129.95. Add an AR Upper for just $219.99. And then stock up on mags and ammo with equally awesome deals. For just $359.99 you can get 1000 rounds of Federal American Eagle 5.56 ammo plus TEN (10) Magpul 30-rd mags. AMMO and MAGs Deal HERE.
PSA Complete Lower and Upper at Huge Discounts
Right now you can get a complete PSA Lower with Flat Dark Earth grip and stock, for just $129.99. That’s a steal. If you need an AR Upper you can get a basic 16″ Upper with FDE handguard, Picatinny scope rail, and 1:7″ twist barrel. These components have both earned five stars from scores of actual PSA buyers.
Great Package Deal on Federal Ammo and Magpul Magazines
This Federal ammo is quality, American Eagle 5.56mm 55 Grain XM193BK FMJBT Ammunition packed in a bulk box. So all 1000 rounds is in one big box. XM193 product is first-quality product manufactured at the Army’s Lake City Ammunition Plant for Federal Cartridge. NOTE: All XM193 product is the same regardless of the sku or part number. The only difference is the package configuration.
The PMAG 30 is a 30-round 5.56×45 NATO (.223 Remington) AR15/M4 compatible magazine that offers a cost competitive upgrade from the aluminum USGI. Easy to load and dissasemble, the PMAG features rugged polymer construction, flared floorplate for positive mag extraction, stainless steel spring, and an anti-tilt, self-lubricating follower for increased reliability.
At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
1. LongShot Cameras (TargetVision) — CyberSale Save Up to $100
Longshot Cameras (aka TargetVision) makes the best long-range target camera systems on the market. These deliver sharp, clear images from impressive distances. View on your mobile device. You can even mark/score your shots with Longshot’s mobile Apps. Right now you can save on ALL LongShot Camera products. The superb LongShot LR-3 2-mile UHD (Ultra-High-Definition) is now just $699.00 on sale, while the 300-yard UHD Marksman is on sale for $349.00. The new Hawk Spotting Scope camera is a steal at $249.00, marked down from $299.00. Act soon — these deals expire 12/2/2019.
2. Powder Valley — Free HazMat Starting 11/29/19 — All Brands
Need powder and/or primers? Then head over to Powder Valley. Starting November 29, 2019 (this coming Friday), you can get FREE HazMat for all brands of reloading powder and primer. And yes you can combine powder and primers in the same shipment. This great FREE HazMat offer runs through December 2, 2019. Go to PowderValleyInc.com and select FREE HazMat during checkout, starting Friday November 29th.
3. EuroOptic.com — HUGE Nikon Scope Close-Out Sale
Nikon is getting out of the riflescope business. Nikon will continue to make spotting scopes, binoculars, and rangefinders — but no more riflescopes. That means HUGE close-out savings! EuroOptic.com is running a close-out sale on Nikon riflescopes. This sale includes the excellent Black FX1000 (FFP), and Black X1000 (SFP) tactical scopes. If you are looking for a great tactical or hunting scope at a crazy low price, head over to EuroOptic this week. For example the 4-16x50mm FX1000 MRAD is marked down from $749.95 to just $369.95, a 50% savings!
4. XLR Industries — Chassis System Discounts, $50-$300
If you’re a fan of modular chassis systems, here’s a great early Black Friday Sale. Starting today 11/27/19, XLR Industries is offering huge discounts on their modern metal/composite chassis systems, which are made for Remington, Savage, Howa, and Tikka actions both right- and left-hand. Use these Discount Codes to save up to $300 on a purchase: BLK300 ($1000+ order); BLK200 ($750-$999 order); BLK150 ($595-$749 order); BLK50 ($250-$594 order).
5. Midsouth — New .308 Win Lake City Brass, $79.99/250 cases
Midsouth Shooters has acquired a large quantity of excellent Lake City 7.62×51 (.308 Win) Primed Brass. NOTE, this is New Brass that has never been fired. However it is described as “pull-down”, meaning the brass had originally been assembled into loaded ammo. The brass comes PRIMED with CCI #34 primers, with crimped primer pockets. The brass is sold in 250-count bags for $79.99. That works out to just $0.32 per case — a great deal for primed, strong Lake City Brass. This is good stuff for M1As and hunting rifles.
6. Midsouth — Tipton Best Gun Vise 2, $78.99
Midsouth has the Tipton Best Gun Vise 2 for just $78.99, a fine deal on a versatile, highly adaptable unit. An Amazon #1 Best Seller, this deluxe gun vise has earned much praise from owners. Or if you want something more basic that’s easier to move around, check out the Tipton Cleaning Gun Vise for $45.99 from Midsouth — a very attractive price. Either way you can’t go wrong.
7. Grizzly Industrial — Bald Eagle Slingshot Rest, $129.97
Maybe you’re just getting into F-Class or just need a good stable front rest to shoot from and don’t want to spend a ton of money on one. Don’t worry because Grizzly now has the Bald Eagle BE1129 aluminum slingshot rest for an amazingly low $129.97 close-out price. Just add your favorite front bag and you’re ready to go with a competition quality elevation adjustable rest. They also have the Bald Eagle BE1209 – Big Fifty Rest on sale now for $176.97 close-out price. With a much wider span and cast-iron legs, the Big Fifty is designed for larger guns up to .50 caliber. Either way, these rests are a great value.
8. Amazon — MTM AC4C Ammo Crate with 4 Ammo Boxes, $22.99
Here’s a very cool product from MTM at a great price. The versatile MTM AC4C Ammo Carrier features four, lockable polymer ammo cans in a fitted, four-slot 23.5″ x 11.3″ x 7.5″ carry crate. This makes it easy to haul four full ammo cans. Actual purchasers have raved: “Moments after I received this storage box set I ordered another. Very well built and great design. Awesome and a steal at the price.” Right now this is on sale at Amazon for just $22.99 with free shipping on orders over $25. The system includes four lockable, O-Ring 11.3″ x 7.2″ x 5″ ammo cans (AC30T) for multi-caliber ammo storage. The crate even includes tie-down points for transport in a cart or ATV. NOTE: Last year this MTM AC4C system sold for $39.99. The current $22.99 price represents a 43% savings! Our Deals Editor recently ordered this himself and he liked it so much he immediately ordered another AC4C kit.
9. Amazon — Tactical Eyewear Kit, $15.99
Wearing eye protection should be second nature for anyone around firearms for so many obvious reasons. Whether for you, a backup or to have for those shooting with you grab a set of XAegis Tactical Eyewear Kit that come complete with 3 different lenses and protective case. You can easily switch from Gray, to Yellow, to Clear lenses, popping them into the frame. This 3-Lens shooting Kit is an Amazon #1 Best Seller.
We love shooting reactive targets — the instant gratification of hearing the “clang” and seeing the target fall or spin is addictive. However, there are some significant downsides of steel targets. They are heavy/cumbersome to move around. With steel targets you must be careful with ricochets and bullet splatter. Finally, to keep them looking good, you have to re-apply surface paint time after time.
Newbold Targets sells self-sealing reactive polymer targets that work like steel, but have none of the major disadvantages. Seven times lighter than steel, they are easy to transport and set-up. Though they can “react” like steel, bullets pass right the self-sealing polymer, so you don’t have to worry about ricochets or bullet “splashback”. Finally, you never have to paint them.
Newbold polymer targets come in bright colors that last the life of the target. They are affordable — small auto-reset polymer targets start at $1.49, KD-Pivot Silhouettes run $3.99 – $8.99, 3″ Rifle targets run $8.99 while the larger competition series Knock-Down “plates” (shown below) are $18.99 each. Dozens of different polymer targets are available. There are standing targets, hanging targets, and pivoting targets.
Newbold’s KD Competition Series targets can be reset with a simple string.
Newbold offers a variety of self-sealing reactive targets, such as the KD-Pivot plate rack targets above, hanging targets, 3-Gun targets, and the 42″ popper targets shown in the video below. Many of the Newbold targets have reset systems — simply pull a lanyard and the targets pop back up.
Gunwriter Tom McHale has tested Newbold Polymer Targets and likes them: “There’s one more significant advantage over steel. You can shoot them at any distance, including point-blank range. Since the bullets pass through… there’s no fragmentation or splash as there is with steel targets.”
Ever wondered what caused a particular bulge or marking on a case? And more importantly, does the issue make the case unsafe for further use? Sierra Bullets Ballistic Technician Duane Siercks offers some insight into various issues and their causes in two Case Diagnostic articles from the Sierra Blog.
Incipient Case-Head Separation
This is a Winchester .308 Win case that has a real issue. This case has a very obvious incipient case head separation in the process of becoming a complete failure.
This is most commonly caused by over-sizing the case causing there to be excess headspace on the case. After a few firings and subsequent re-sizing, this case is just about ready to come completely apart. Proper die adjustment is certainly a requirement here. Of course this case is not safe to reuse.
Excessive Pressure (Load Too Hot)
If you will notice in the picture of the case rim, there are two pressure signs to notice. First, look at the primer. It is basically flattened to about the max of what could be considered safe. If this was the only pressure sign noted, I would probably be fine with this load, but would constantly keep an eye on it especially if I was going to use this load in warmer temperatures. This load could easily cross into the “excess pressure” realm very quickly.
There is another sign of pressure that we cannot ignore. If you’ll notice, there is an ejector mark apparent that is located over the “R” of the R-P headstamp. This absolutely tells us that this load would not have been in the safe pressure range. If there were any of these rounds loaded, they should not be fired and should be dis-assembled. This case should not be reloaded.
Split Case-Neck
Here we have an R-P .22-250 case that has died the death. Everything looks fine with this case except the neck is split. This case must be tossed.
A split neck is a normal occurrence that you must watch for. It is caused by work-hardening of the brass. Brass cases get harder with age and use. Brand new cases that are stored for a period of time can become hard enough that they will split like this case within one to two firings. I have had new factory loads do the same thing. Then as we resize and fire these cases repeatedly, they tend to get harder and harder. Eventually they will split. The life of the case can be extended by careful annealing practices. This is an issue that would need to be addressed in an article by itself. Of course this case is no longer usable.
In the classes that I teach, I try to use examples like this to let the students see what they should be looking for. As always, if we can assist you, whether you are new to reloading or very experienced, contact us here at Sierra Bullets by phone at 1-800-223-8799 or by email at sierra@sierrabullets.com.
Dented Case Body
Here we have a Lake City 7.62×51 (.308 Win.) case with two heavy marks/dents in the case body.
This one may be a bit of a mystery. It appears as if this case may have been caught in the action of a semi-auto rifle when the firearm jammed or the case failed to clear during the cycling process. I probably would not reload this case just to prevent any feeding problems. This also appeared to be a factory loaded round and I don’t really see any pressure issues or damage to the case.
Multiple Problems — Lake City 5.56×45 unknown year.
This case has suffered multiple failures and cannot be re-used. First its has have a very rounded shoulder that is split. Upon first look it was obvious that this round had been a victim of excess pressure. The firearm (perhaps an AR?) was apparently not in full battery, or there was possibly a headspace issue also. While taking a closer look, the primer was very flat and the outside radius of the primer cup had been lost. High pressure! Then I also noticed that there was an ejector mark on the case rim. This is most certainly an incident of excessive pressure. This case is ruined and should be discarded.
It is very important to observe and inspect your cases before each reloading. After awhile it becomes second nature to notice the little things. Never get complacent as you become more familiar with the reloading process. If ever in doubt, call Sierra’s Techs at 1-800-223-8799.
Readers — if you reload with Accurate-brand 2495, 4064, or 4350 powders, check your containers now! Accurate Powder is recalling certain lots of these powders in both 1-lb and 8-lb containers. This is serious. The manufacturer says: “The use or storage of this product may result in combustion, fire damage, and/or possible serious injury or property damage.” The problematic powders being recalled were manufactured for Western Powders Inc. prior to 10/1/2016, but they may have been sold anytime after that.
Check the Lot Number on the back or bottom of the containers. The lot number is the last digit or last two digits (right-most digits). Here are the recalled lots:
Accurate 2495 Lots 2-17 | Accurate 4064 Lots 2-16 | Accurate 4350 Lots 2-22
If you have any of the affected powder you should fill the container immediately with WATER. Then contact Western Powders at 406-234-0422 or customerservice@westernpowders.com .
Accurate Powders Recall Notice for 2495, 4064, 4360 Powders
Recall tip from EdLongrange. We welcome reader submissions.
What would you do if you had a LIVE Round stuck in a chamber? Well, don’t hammer a wood dowel in the barrel, that’s for sure. Here is a tale of stupidity that could have injured the rifle owner. This account appeared on the Facebook Page of Brock & Norris Custom Rifles, a gunsmith shop in the United Kingdom.
Live, Loaded Round Stuck in Chamber — What NOT to Do!
Commentary by gunsmith Mike Norris
Here is a cautionary tale. A client came into the workshop with a problem which could have had very serious [even deadly] consequences. And it is not the first time we have seen this. Firing neck-sized-only ammunition, the client attempted to load a round which then jammed solid in the chamber. The bolt would not close and the round was unable to be extracted.
The problem was compounded by various attempts to push the loaded round from the chamber with cleaning rods and the assistance of a hammer (I kid you not!). All of which damaged the bore and the crown, culminating in a wooden dowel being hammered into the barrel which subsequently broke off in the bore. The end result was a barrel that was totally wrecked.
One Facebook friend posted: “Fortunate avoidance of a ‘Darwin Award’. I can hear it: ‘Go on hammer the bolt, she’ll go!’. We’re missing a ‘face palm’ emoji here.”
The Problem Started with a Neck-Sized Case
The moral of this story is DO NOT NECK SIZE cases. Mike advises: “Full-length size cases correctly. You only move the shoulder back 1 to 1.5 thousandths and the case will feed and extract EVERY TIME. Yes you will have to trim cases occasionally but it is one hell of a site cheaper and safer than jamming a live round in the barrel and wrecking the barrel trying to remove it. Not to mention the risk to life and limb!”
What Should Have Been Done in this Situation?
Mike was asked the best method for removing a stuck round. He stated: “The Grease Gun Method on a threaded barrel works*. However, in this case, this was not remotely possible due to 20 inches of wooden dowel being broken off in the bore as well. The live round (yes it was live!) was attempted to be removed by hammering on a brass cleaning rod (an actual hammer was used) to try to dislodge it. That brass rod broke, so then a wooden dowel was employed, and THAT broke as well.”
Mike cautions that, when a live, loaded round is involved you must be very careful: “Do not be taking chances with your own safety or others around you. When it is safe to do so, get the rifle to a professional. By the way he WILL [chide you] for being daft in the first place and then bringing the problem into his premises. Expect to be charged for the expertise to remove said obstruction, In the past I even had a client send me a loading die with a live .338 Lapua round in it through the Post no less!”
* This YouTube Video shows the successful removal of a jammed FIRED (not live) case from an AR15 barrel. You can see the fired case eject at 15:35 time-mark, after the primer pops out first. But note, this was NOT a live, loaded round. Extreme caution must be excercised with live rounds.
A hot new 6mm match bullet has arrived — the impressive Berger 109-grain Hybrid. This new 109-grainer, officially called the Long Range Hybrid Target (LRHT), features a formed meplat (bullet tip) for more consistent Ballistic Coefficient (BC). Berger tells us that the new 109gr LRHT boasts a high-BC, “jump-tolerant” hybrid ogive profile along with an extremely consistent BC. In fact, Doppler Radar testing confirms less than 1% BC variation from bullet to bullet. While a high BC is of course desirable for competitive shooting, shot-to-shot BC consistency is most critical when engaging targets to 600 yards and beyond. The 109’s BC numbers are very impressive for a 6mm bullet: 0.568 G1 and 0.292 G7.
AccurateShooter.com plans to test these new 109s very soon — we’re getting them into the hands of some championship-level shooters. The new 109s should prove very popular. These bullets are optimized for leading accuracy cartridges such as 6mm Creedmoor, 6mmBR, 6BRA, 6mm Dasher, 6BRX, 6GT, 6XC, and 6×47 Lapua among others. NOTE: Berger states that the new 109gr LRHT offers the same stability factor as Berger’s outstanding 105gr Hybrid Target. Accordingly, the new 109 can be considered a “direct replacement” for the 105s. And YES, the 109gr LRHT will work in 1:8″-twist barrels.
“The 6mm 109 offers several advantages,” said Bryan Litz, Berger’s Chief Ballistician. “Its ultra-sleek profile provides a higher Ballistic Coefficient (BC) resulting in less wind drift at all ranges. Using the proprietary MRT technology also results in a higher and more consistent BC, which is important for reducing dispersion at long range.”
Meplat Reduction Technology for More Consistent BCs
Berger’s new 6mm 109-grain Long Range Hybrid Target™ Bullets is designed to provide Benchrest, F-Class, and PRS enthusiasts a class-leading level of precision and consistency. Utilizing advanced/proprietary manufacturing processes, Berger’s Meplat Reduction Technology™ (MRT™) System applies controlled pressure along the projectile nose, producing a homogeneous and repeatable bullet profile. This yields what Berger claims are “the industry’s most consistent Ballistic Coefficients (BC)”.
The Berger 6mm 109 Grain Long Range Hybrid Target™ Bullets will be available very soon at authorized Berger Retailers. Use the Berger Dealer Locator to find a store near you.
At the request of our readers, we provide select “Deals of the Week”. Every Sunday afternoon or Monday morning we offer our Best Bargain selections. Here are some of the best deals on firearms, hardware, reloading components, optics, and shooting accessories. Be aware that sale prices are subject to change, and once clearance inventory is sold, it’s gone for good. You snooze you lose.
1. Bullet Central — Lapua Brass Sale
We’re coming up on the end of the year and that means it won’t be long until it’s time for matches. Get ahead during the off season by taking advantage of the Lapua brass sale at Bullet Central. It’s smart to buy your brass for the 2020 season now, so you can do your brass prep and loading during the winter months.
The LabRadar is arguably the most sophisticated consumer chronograph on the market. These units rarely go on sale — but here’s your chance. Right now you can now get a LabRadar for $499.95 — that’s $60 off the normal price. (Sale price good through December 2, 2019). Purchase direct from Mylabradar.com, or order from leading vendors Midsouth Shooters (in-stock $499.95), Bruno’s (back-order $499.95), and Creedmoor Sports ($499.95 in stock).
3. Brownells — Giant Ammo Clearance
You can find discounts on certain ammunition brands at various vendors, but we’ve never seen a huge clearance like this with so many ammo types on sale. Take some time to check out all the amazing Ammo Clearance Deals now at Brownells. Over 1800 products are clearance priced so there’s sure to be something for everyone.
4. Natchez — Holiday Discount Codes, Save $10, $25, $40
Right now you can get direct money OFF nearly all products at Natchez Shooters Supply. Save $10 on purchases of $100 or more with CODE D191118A, or save $25 on $200 with CODE D191118B, or save a full $40 (13.3%) on orders of $300 or more with CODE D191118C. You must act soon, however, as these Discount Codes expire at 11:59 pm November 20, 2019. Some restrictions apply.
5. Field & Cave Outfitters — Silhouette Targets, up to 40% off
If you’re tired of shooting at paper targets, check out these sturdy varmint benchrest silhouette targets from Field & Cave Outfitters. There are a variety of animals to choose from. Right now you can save up to 40% off on these quality steel silhouette targets. The Prairie Dog and Armadillo are laser-cut and bent 18ga cold-rolled steel. The Coyote and Hog are 3/8″-thick AR500 steel, laser- cut then welded.
Here’s a great deal for those looking to either add a handgun to their collection or for those just getting started in the shooting sports. We found the Ruger Security-9 in 9mm for a great price of $279.99. Under $280 for a reliable, sturdy Ruger 9mm — that’s a smart choice for personal defense. This features a blued steel slide, 4″ barrel, polymer frame, and 15-rd magazine.
7. Amazon — Padded Shooting Mat, $37.99
Are you new to prone shooting or tired of using an old worn out mat? Grab one of these Redneck Convent padded shooting mats and you shoot in style and comfort all day long. These pads are weather, chemical and water resistant and the durable PVC material is easy to clean and maintain. Best of all it rolls up for easy storage and transport.
8. Midsouth — Frankford Arsenal Vibra Prime, $39.99
Do you still load up your priming tubes the old fashion way, one at a time out of a flip tray? Save yourself time and trouble with the Frankford Arsenal Vibra Prime Primer Tube Loader. This tool loads a universal primer tube in just seconds and can transfer the primers to just about any brand primer tube just as easily. We’ve used one of these for years without Hornady, RCBS and Dillon tubes without any issues.
9. Amazon — Waterproof Clipboard, $19.98
Planning on hitting the range or that next match but the forecast says there might be a few showers? Fear no more as you can grab one of these waterproof clipboards and keep your load data notes or your shooting partners scores safe and dry. We keep one of these with us anytime we go to a match because you can flip it over and use it as a regular clipboard when it’s dry too!
You may not realize it… but to get the optimum BC from your bullets (i.e. the lowest aerodynamic drag), you must spin the bullets fast enough. Bullet drag increases (as expressed by lower BC) if the bullet spins too slowly. Bryan Litz of Applied Ballistics explains how BC changes with twist rates…
More Spin, Less Drag
In this article, we look at how twist rate and stability affect the Ballistic Coefficient (BC) of a bullet. Again, this topic is covered in detail in the Modern Advancements book. Through our testing, we’ve learned that adequate spin-stabilization is important to achieving the best BC (and lowest drag). In other words, if you don’t spin your bullets fast enough (with sufficient twist rate), the BC of your bullets may be less than optimal. That means, in practical terms, that your bullets drop more quickly and deflect more in the wind (other factors being equal). Spin your bullets faster, and you can optimize your BC for best performance.
Any test that’s designed to study BC effects has to be carefully controlled in the sense that the variables are isolated. To this end, barrels were ordered from a single barrel smith, chambered and headspaced to the same rifle, with the only difference being the twist rate of the barrels. In this test, 3 pairs of barrels were used. In .224 caliber, 1:9” and 1:7” twist. In .243 caliber it was 1:10” and 1:8”, and in .30 caliber it was 1:12” and 1:10”. Other than the twist rates, each pair of barrels was identical in length, contour, and had similar round counts. Here is a barrel rack at the Applied Ballistics Lab:
Applied Ballistics used multiple barrels to study how twist rate affects BC.
“The Modern Advancements series is basically a journal of the ongoing R&D efforts of the Applied Ballistics Laboratory. The goal of the series is to share what we’re learning about ballistics so others can benefit.” –Bryan Litz
Barrel twist rate along with velocity, atmospherics, and bullet design all combine to result in a Gyroscopic Stability Factor (SG). It’s the SG that actually correlates to BC. The testing revealed that if you get SG above 1.5, the BC may improve slightly with faster twist (higher SG), but it’s very difficult to see. However, BC drops off very quickly for SGs below 1.5. This can be seen in the figure below from Modern Advancements in Long Range Shooting.
The chart shows that when the Gyroscopic Stability Factor (SG) is above 1.5, BC is mostly constant. But if SG falls below 1.5, BC drops off dramatically.
Note that the BC drops by about 3% for every 0.1 that SG falls below 1.5. The data supports a correlation coefficient of 0.87 for this relationship. That means the 3% per 0.1 unit of SG is an accurate trend, but isn’t necessarily exact for every scenario.
It’s a common assumption that if a shooter is seeing great groups and round holes, that he’s seeing the full potential BC of the bullets. These tests did not support that assumption. It’s quite common to shoot very tight groups and have round bullet holes while your BC is compromised by as much as 10% or more. This is probably the most practical and important take-away from this test.
To calculate the SG of your bullets in your rifle, visit the Berger Bullets online stability calculator. This FREE calculator will show you the SG of your bullets, as well as indicate if your BC will be compromised (and by how much) if the SG is below 1.5. With the stated twist rate of your barrel, if your selected bullet shows an SG of 1.5 (or less), the calculator will suggest alternate bullets that will fully stabilize in your rifle. This valuable online resource is based directly on live fire testing. You can use the SG Calculator for free on the web — you don’t need to download software.
