Here’a useful article by Sierra Bullets Media Relations Manager Carroll Pilant. This story, which originally appeared in the Sierra Bullets Blog, covers some of the more common ammo problems that afflict hand-loaders. Some of those issues are: excessive OAL, high primers, and improperly-sized cases. Here Mr. Pilant explains how to avoid these common problems that lead to “headaches at the range.
I had some gentlemen at my house last fall getting rifle zeros for an upcoming elk hunt. One was using one of the .300 short mags and every 3rd or 4th round would not chamber. Examination of the case showed a bulge right at the body/shoulder junction. These were new cases he had loaded for this trip. The seating die had been screwed down until it just touched the shoulder and then backed up just slightly. Some of the cases were apparently slightly longer from the base to the datum line and the shoulder was hitting inside the seating die and putting the bulge on the shoulder. I got to thinking about all the gun malfunctions that I see each week at matches and the biggest percentage stem from improper handloading techniques.
One: Check Your Cases with a Chamber Gage
Since I shoot a lot of 3-gun matches, I see a lot of AR problems which result in the shooter banging the butt stock on the ground or nearest solid object while pulling on the charging handle at the same time. I like my rifles too well to treat them that way (I cringe every time I see someone doing that). When I ask them if they ran the ammo through a chamber gage, I usually get the answer, “No, but I need to get one” or “I didn’t have time to do it” or other excuses. The few minutes it takes to check your ammo can mean the difference between a nightmare and a smooth running firearm.
A Chamber Gauge Quickly Reveals Long or Short Cases
Size Your Cases Properly
Another problem is caused sizing the case itself. If you will lube the inside of the neck, the expander ball will come out a lot easier. If you hear a squeak as the expander ball comes out of a case neck, that expander ball is trying to pull the case neck/shoulder up (sometimes several thousandths). That is enough that if you don’t put a bulge on the shoulder when seating the bullet … it can still jam into the chamber like a big cork. If the rifle is set up correctly, the gun will not go into battery and won’t fire but the round is jammed into the chamber where it won’t extract and they are back to banging it on the ground again (with a loaded round stuck in the chamber). A chamber gage would have caught this also.
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
Just a quick tip — To extract the partial case, an oversized brush on a cleaning rod [inserted] and then pulled backward will often remove the case. The bristles when pushed forward and then pulled back act like barbs inside the case. If you have a bunch of oversized case that have been fired, I would dispose of them to keep from having future problems. There are a few tricks you can use to salvage them if they haven’t been fired though. Once again, a case gage would have helped.
Two: Double Check Your Primers
Another thing I see fairly often is a high primer, backwards primer, or no primer at all. The high primers are bad because you can have either a slam fire or a misfire from the firing pin seating the primer but using up its energy doing so. So, as a precaution to make sure my rifle ammo will work 100% of the time, I check it in a case gage, then put it in an ammo box with the primer up and when the box is full, I run my finger across all the primers to make sure they are all seated to the correct depth and you can visually check to make sure none are in backwards or missing.
Three: Check Your Overall Cartridge Length
Trying to load the ammo as long as possible can cause problems also. Be sure to leave yourself enough clearance between the tip of the bullet and the front of the magazine where the rounds will feed up 100%. Several times over the years, I have heard of hunters getting their rifle ready for a hunt. When they would go to the range to sight in, they loaded each round single shot without putting any ammo in the magazine. On getting to elk or deer camp, they find out the ammo is to long to fit in the magazine. At least they have a single shot, it could be worse. I have had hunters that their buddies loaded the ammo for them and then met them in hunting camp only to find out the ammo wouldn’t chamber from either the bullet seated to long or the case sized improperly, then they just have a club.
Four: Confirm All Cases Contain Powder
No powder in the case doesn’t seem to happen as much in rifle cartridges as in handgun cartridges. This is probably due to more handgun ammo being loaded on progressive presses and usually in larger quantities. There are probably more rifle cartridges that don’t have powder in them than you realize though. Since the pistol case is so much smaller internal capacity, when you try to fire it without powder, it usually dislodges the bullet just enough to stick in the barrel. On a rifle, you have more internal capacity and usually a better grip on the bullet, since it is smaller diameter and longer bearing surface. Like on a .223, often a case without powder won’t dislodge the bullet out of the case and just gets ejected from the rifle, thinking it was a bad primer or some little quirk.
For rifle cases loaded on a single stage press, I put them in a reloading block and always dump my powder in a certain order. Then I do a visual inspection and any case that the powder doesn’t look the same level as the rest, I pull it and the one I charged before and the one I charged after it. I inspect the one case to see if there is anything visual inside. Then I recharge all 3 cases. That way if a case had powder hang up and dump in the next case, you have corrected the problem.
On progressive presses, I try to use a powder that fills the case up to about the base of the bullet. That way you can usually see the powder as the shell rotates and if you might have dumped a partial or double charge, you will notice as you start to seat the bullet if not before. On a progressive, if I don’t load a cartridge in one smooth stroke (say a bullet tipped over sideways and I raised the ram slightly to reset it) Some presses actually back the charge back adding more powder if it has already dumped some so you have a full charge plus a partial charge. When I don’t complete the procedure with one stroke, I pull the case that just had powder dumped into it and check the powder charge or just dump the powder back into the measure and run the case through later.
Sierra Bullets has published load data for the 6mm Creedmoor cartridge, a necked-down version of the popular 6.5 Creedmoor. Sierra has released very comprehensive 6mm Creedmoor load data, covering fifteen (15) different bullets from 55 to 110 grains. NOTE: Hornady-brand brass was used for Sierra’s 6mm Creedmoor load tests, not the newer, stronger Lapua 6.5 CM brass with small primer pockets. Hand-loaders using Lapua 6.5 Creedmoor brass necked to 6mm may have to adjust their loads.
Sierra writes: “As soon as the 6.5 Creedmoor was released in 2007, a 6mm version was being envisioned. After the 6mm Creedmoor demonstrated its worth at 1000 yards it began to catch the attention of Precision Rifle Series (PRS) competitors. The 6mm Creedmoor is a great fit for those looking for an AR platform-friendly cartridge. It delivers velocities very similar to the .243 Win and yet fits the AR10 magazine length[.] The 30-degree shoulder makes this a very efficient case and helps prolong case life as well. The 6mm Creedmoor works well with powders such as H4350, [RE-16], RE-17, and Ramshot Hunter for heavier long-range bullet weights. Slightly faster powders such as RE-15, Win 760, and Vihtavuori N540 work well with lighter weight bullets.”
Sierra Bullets Tested for 6mm Creedmoor Load Data
55gr BlitzKing (#1502)
60gr HP (#1500)
70gr HPBT (#1505)
70gr BlitzKing (#1507)
75gr HP (#1510)
In developing its 6mm Creedmoor load data, Sierra tested a very wide selection of propellants, two dozen overall. For the smaller bullets, fast-burning powders such as Benchmark, H4895, and CFE223 were tested. For the heavier 100+ grain bullets, Sierra tested a selection of medium-burn-rate powders including H4350, Reloder 16, Reloder 17, Varget, and Superformance. Sierra did a very thorough job. We know this information will be welcomed by 6mm Creedmoor shooters.
Don’t know what powder to try first? For the 107-110 grain bullets, if you want best accuracy and low ES/SD, our Forum members recommend Alliant Reloder 16 and Hodgdon H4350. If you are seeking max velocity with the 110-grainer, look at Hodgdon Superformance and Reloder 19.
Here are Sierra’s 6mm Creedmoor Load Data Charts for 90-95 grain bullets plus the 107gr MK and 110gr MK. There are five other tables for other bullet types.
BONUS: PRB 6mm Creedmoor and 6.5 Creedmoor Load Survey
The Precision Rifle Blog compiled Load Data from PRS Competitors, for both 6mm Creedmoor and 6.5 Creedmoor. This is a good place to start. PRB surveyed the match loads for “173 of the top-ranked precision rifle shooters in the country”. One cautionary note: These PRS guys may be loading fairly hot, so work up gradually, 0.3 grains at a time. CLICK HERE.
Based on the questions we get on a daily basis on our 800 (Customer Support) line, twist is one of the most misunderstood subjects in the gun field. So let’s look deeper into this mystery and get a better understanding of what twist really means.
When you see the term 1:14″ (1-14) or 1:9″ twist, just exactly what does this mean? A rifle having a 1:14″ twist means the bullet will rotate one complete revolution every fourteen inches of the barrel. Naturally a 1:9″ turns one time every nine inches that it travels down the barrel. Now, here’s something that some people have trouble with. I’ve had calls from shooters thinking that a 1:14″ twist was faster than a 1:9″ because the number was higher with the 1:14″. The easiest way to remember this is the higher the number, the slower the twist rate is.
Now, the biggest misconception is that if a shooter has a .223 with a 1:8″ twist, his rifle won’t stabilize a 55gr bullet or anything lighter. So let’s look at what is required. The longer a bullet is for its diameter, the faster the twist has to be to stabilize it. In the case of the .223 with a 1:8″ twist, this was designed to stabilize 80gr bullets in this diameter. In truth the opposite is true. A 1:8″ will spin a 55gr faster than what is required in order to stabilize that length of bullet. If you have a bullet with good concentricity in its jacket, over-spinning it will not [normally] hurt its accuracy potential. [Editor’s Note: In addition, the faster twist rate will not, normally, decrease velocity significantly. That’s been confirmed by testing done by Bryan Litz’s Applied Ballistics Labs. There may be some minor speed loss.]
Many barrel-makers mark the twist rate and bore dimensions on their barrel blanks.
Think of it like tires on your truck. If you have a new set of tires put on your truck, and they balance them proper at the tire shop, you can drive down a street in town at 35 MPH and they spin perfect. You can get out on the highway and drive 65 MPH and they still spin perfect. A bullet acts the same way.
Once I loaded some 35gr HP bullets in a 22-250 Ackley with a 1:8″ twist. After putting three shots down range, the average velocity was 4584 FPS with an RPM level of 412,560. The group measured .750″ at 100 yards. This is a clear example that it is hard to over-stabilize a good bullet.
Twist-rate illustration by Erik Dahlberg courtesy FireArmsID.com. Krieger barrel photo courtesy GS Arizona.
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.
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.
NOTE: All listed products are for sale to persons 18 years of age or older. No products are intended for use by minors.
1. Natchez — Leupold Scope Sale and VH6-HD Rebate
⏺ Large selection of Leupold optics at significant savings
Leupold scopes rank among the best for hunting or target shooting. Leupold’s VX series of scopes offer a wide variety of magnification ranges and reticles. Right now Natchez is running a major Leopold sale. You can save hundreds on Leupold scopes, ranging from the 1-6x24mm VX-6HD to the powerful 4-24x52mm VX-6HD, now $1899.99, which is $500.00 off the original price. Leupold spotting scopes, binoculars, and laser rangefinders are also on sale.
The Natchez sale prices reflect a manufacturer’s price reduction of $300 on VX-6HD scopes. This Leupold promo applies to select VX-6HD riflescopes purchased from July 24 through September 3, 2023.
2. Creedmoor Sports — Sierra Bullet Sale
⏺ Big savings on popular Sierra match bullets
If you hand-load for hunting or competition you need quality bullets. Sierra makes great bullets in popular calibers with both hunting and match versions such as the Sierra MatchKing. Creedmoor Sports has significant discounts right now on .224, 6.5mm, .308, and .338 caliber Sierra bullets, including the latest generation MatchKings which come with uniformed tips from the factory.
3. Midsouth — New LEE Deluxe APP Processing Press, $109.99
⏺ Unique processing unit does many bulk tasks efficiently
The very affordable LEE Deluxe APP (Automatic Processing Press) performs a number of key reloading functions efficiently. This new Deluxe APP can prime a large number of cases rapidly, employing a clever case-feeding system. The Deluxe APP also has a very good depriming operation. Key features in this upgraded system include: Universal Case Feeder, APP Deprime Kit, Priming System, Deluxe Roller Handle, and Bottle Adapter. This complete set-up is on sale this week for $109.99, a 15% ($20) savings.
4. MidwayUSA — Sierra .223 Rem Hunting Ammo, $9.99/20 rds
⏺ Super deal on quality .223 Rem ammunition for hunting/varminting
Need quality .223 Rem hunting ammo? Right now Sierra .223 Rem Outdoor Master 55gr JHP ammunition is just $9.99 for a 20-rd box. That’s $0.50 per round, a 56% savings off the regular price. This ammo fits AR15 mags for reliable feeding in AR-platform rifles. This ammo features GameKing Hollow Point BT bullets. The cartridges have quality brass cases, so you can reload the brass many times.
5. Amazon — Lyman Universal Press Stand, $79.70
⏺ Strong, versatile stand works with many press types/brands
Do you wish your reloading press was a little higher so it was more ergonomic to use? A great fix for this is the Lyman Universal Press Stand. This is the only press stand on the market that will accept most current single station, turret, and progressive presses of all brands! This heavy-duty steel stand comes with two mounting plates pre-drilled for your favorite press. If by chance you have a press that does not match up with any of the numerous patterns, there is also a blank area where you can drill your own mounting holes. The stand will raise your press 9¼” above your bench surface, which will lessen fatigue from having to bend over to cycle your press. The raised height also provides a clear view of reloading operations. All hardware needed to mount your press is included.
Many CCW holders prefer 9mm handguns that are small and compact, with smooth edges on the slide and frame. The Ruger EC9s Safety model fits the bill. Slim, lightweight, and compact, this pistol features smooth edges and comes with a Hogue grip sleeve. The striker-fired EC9S features both a manual safety and a Glock-style trigger safety. With 7+1 magazine, but not ammo, this pistol weighs just 18 ounces. It is now on sale for just $249.99 — $139 off (36%) the regular price — a real bargain.
7. Amazon — Caldwell E-Max Shadows PRO Plugs, $123.99
⏺ State of the art electronic plugs with NRR 25 protection
All shooters need quality ear protection. Electronic plugs protect your hearing while allowing you to hear conversations and range commands. The Caldwell E-MAX Shadows Pro plugs are quality electronic plugs with a 25 dB Noise Reduction Rating — very good for plugs alone. These E-MAX plugs come with multiple size tips to help ensure a good fit. Controls on each of the ear pieces allow for volume and mode adjustments while an optional lanyard keeps the earbuds secure. NOTE: These plugs will connect with your mobile device via Bluetooth. In addition, the included storage case serves as a charger for the plugs!
8. Amazon — G4Free Sling Pack with Pistol Holster, $27.99
⏺ Sling pack offers ready access plus handgun storage
The advantage of a sling pack is that you can swing it around to the front to easily access the contents. This rugged G4Free Tactical EDC Sling Pack offers multiple pockets plus a Velcro-attached pistol holster. Starting at $27.99, this 10.6″ x 5.9″ x 8.6″ sling pack is offered in four styles: Tan, Green, Black, and Dark Grey Camo. For $5.00 more ($32.99) you can get Sling Pack Combo with an additional 6.3″ x 4.3″ multifunction pouch that can securely hold a pistol plus a mobile device.
9. Amazon — Biometric Pistol Safe, $179.99
⏺ High-tech pistol safe allows instant access with fingerprint or PIN code
If you keep a handgun for defense use at a home or business, you need a secure, but rapid access storage solution. The Biometric Slider Handgun Safe is a good product that allows instant gun access via your fingerprint. This product has a 508 dpi Biometric sensor capable of storing 20 unique fingerprints for ultra-fast entry. You can also use manual keys or a 4-8 digit PIN code. This system easily mounts to the inside of a desk or the side of a nightstand.
10. Amazon — Vortex Bubble Level, From $31.20
⏺ High quality scope level for 1″, 30mm, 34mm, and 35mm optics
All serious competitive shooters should have a bubble level because rifle cant (angle rotated off bore axis) will alter shot Point of Impact. The Vortex bubble level is a high-quality level that is available for 1″, 30mm, 34mm, and 35mm scope diameters. This level features a quick and easy mounting system.
Here is the original Sierra manufacturing facility in Whittier, CA.
In August 22, 2017 Sierra Bullets was acquired by Clarus Corporation (NASDAQ: CLAR), a Utah-based holding company that also owns Black Diamond Equipment Ltd., makers of ski and mountain gear/apparel. Sierra remains one of America’s leading producers of bullets and loaded ammunition. This article covers Sierra’s notable history, and also reviews Sierra’s processes for crafting and testing bullets.
Sierra Bullets — How It Got Started
Report Based on Story by Carroll Pilant, Sierra Bullets Media Relations Manager
What became Sierra Bullets started in the late 1940s in a Quonset hut in California. In 1947, three aircraft machinists, Frank Snow, Jim Spivey, and Loren Harbor, rented machine space to produce rivets for aircraft along with fishing rod guides and rifle front sight ramps. In the post-WWII years, sport shooting was becoming hugely popular, but quality ammunition was in short supply. For shooting enthusiasts, reloading was the solution to the ammo supply shortage. Snow, Spivey, and Harbor recognized this, creating Sierra Bullets to help fill the void. Before long, they were selling a 53-grain match bullet to the Hollywood Gun Shop. These bullets are still in production today as the Sierra #1400 53-grain MatchKing.
A few years later, an accomplished competitive shooter named Martin Hull joined Sierra. Hull helped develop new bullet types and served as manager of Sierra’s ballistics laboratory for nearly 20 years. With Hull’s help, Sierra’s output grew rapidly. The California company outgrew several locations before it moved to a large facility in Santa Fe Springs, CA, in 1963.
New Owners and New President in the Late Sixties
In 1968, the Leisure Group bought Sierra Bullets. Other Leisure Group companies included Lyman Reloading, High Standard Manufacturing Company, Yard Man, Thompson Sprinkler Systems, Flexible Flyer Sleds, and Dodge Trophies (Which made the Oscar and Rose Bowl Game trophies).
Soon after purchasing Sierra, the Leisure Group hired Robert Hayden as President and General Manager. Hayden was a mechanical engineer who had worked for Remington Arms. Hayden remained the president of Sierra for 42 years, retiring in 2012 when Pat Daly became president.
Sierra Moves to Missouri
In 1990, Sierra relocated to Sedalia, Missouri, where the company remains today. Sierra Bullets now employs over 100 people including five full-time ballistic technicians who answer daily reloading and firearms questions by both phone and e-mail.
The Making of MatchKings — How Sierra Produces SMKs
All Sierra bullets begin life as a strip of gilding metal, an alloy consisting of 95% copper and 5% zinc. To meet Sierra’s strict quality requirements, the gilding metal requires three times more dimensional and quality control standards than is considered standard in the copper manufacturing industry.
A blanking press stamps out a uniform disc and forms the cup that will be drawn into the MatchKing jacket. The cup is then polished and sent to a draw press to be drawn into a jacket that is longer than needed for the future MatchKing, thus allowing for the trim process. Press operators constantly check concentricity to make sure we have only quality jackets. The jackets then go to a trimmer where they are visually inspected again.
After being polished a second time, the jacket travels to the bullet press. In the meantime, 80-pound lead billets are being extruded into lead wire for the cores where great care is taken so that the core wire is not stretched. The core wire is lightly oiled before continuing to the bullet press to be swaged.
The lead core wire and trimmed jacket meet at the bullet press where the first stage forms a boattail on the jacket. The lead core is then formed on top of the bullet press and fed down into the jacket. In one stroke of the press, the MatchKing is formed.
Quality control technicians pull samples from each lot of MatchKings to make sure they meet Sierra’s stringent standards. Samples are then sent to Sierra’s 300-meter underground test range (shown below) to be shot for accuracy on mechanical mounts referred to as “unrestricted return to battery rests” that Sierra designed and built in-house.
After inspection, the bullets are placed in the familiar green box along with reloading labels. They are then shrink-wrapped and shipped all over the world.
Sierra Factory Ammunition with Modern Tipped Bullets
Sierra also produces popular competition and hunting factory ammunition. Sierra’s modern GameChanger hunting ammunition has shown very good performance and consistency. For the GameChanger line, Sierra re-engineered its MatchKing bullet into a hollow point design for quick expansion and fitted it with a green tip for ballistic uniformity. The lead-core GameChanger bullets deliver excellent penetration and expansion at a variety of ranges.
We’re in the middle of summer, so many folks will head to the hinterlands on prairie dog safaris. On a good P-Dog adventure, you may shoot hundreds of rounds over a long weekend. So you’ll need plenty of ammo. With these ammo volume requirements, you probably won’t have time to load to benchrest standards, and you may not have the budget for match-grade bullets. To save time you may throw (rather than weigh) your charges, or even load on a progressive press. This all raises the question of ammo accuracy — how good is “good enough”? A Sierra Bullets expert answers that question here — explaining how to efficiently load ammo for varmint work.
Ammunition Accuracy Requirements 101 — Varmint Ammo
This story based on article by Sierra Bullets Chief Ballistician Tommy Todd
I load and shoot ammunition for a living. In my duties here at Sierra I constantly test bullet accuracy for our production needs. Because of this, I shoot a variety of different calibers and cartridges on a daily basis and a large demand of this shooting is keeping the guns and loads tuned for optimum accuracy. I have a very narrow window of tolerances to maintain in order to provide our customers (you) with the most accurate bullets on the market.
I have learned many tricks and techniques over the years to tuning a load, prepping brass, and cleaning barrels to keep a gun shooting. I often utilize the things I have learned and take them to extreme levels when competing in a shooting event. I also often ignore most of these things (other than safety) and simplify the process if the shooting I will be doing does not warrant.
Recently I went on a prairie dog shoot in Wyoming with some good friends. The targets cooperated as did the weather with the exception of some challenging winds we experienced. We had a great time and make a lot of hits on those small rodents. When loading for the .223 Remington rifles and the TC Contender, I cut a few corners in the ammunition-loading process due to both time constraints and accuracy needed. When shooting at a prairie dog a miss is simply that, but when shooting at say the X-Ring at 1000-yard competition, a poorly-placed shot [harms your] placing in the match. Because of this, I can afford to miss an occasional shot at a varmint due to ammunition capability without worry but will not allow the same tolerances in my match ammo. For the Wyoming trip I utilized a powder measure and simply dumped the charges into primed cases that had been full-length sized and primed.
I had measured enough for length to know that while there was some variance all were under maximum length. I know there is some variation of the measure I utilized but not significant enough to warrant weighing every charge. When seating the bullets a competition seating die was used and I verified OAL on the occasional cartridge to make sure nothing changed.
This varmint ammo, with thrown charges, put TEN shots inside ONE inch at 200 yards. That’s half MOA. Good Enough? Absolutely!
The ammo produced shot under one inch at 200 yards in one of the guns I planned on taking on to Wyoming with me. [Editor: That was for TEN Shots — see above.] I knew I had loaded ammunition that was quite suitable for the task at hand which was evidenced by the number of hits I was able to make at fairly long range.
NOTE: The author, Tommy Todd, explains that, when loading ammo for F-Class matches, he uses more exacting methods. He weighs every charge and seats his bullets carefully with an arbor press. Todd adapts his methodology for his particular application. The lesson here is to load to the level of precision demanded by your discipline. READ Full Story HERE.
For load development, some guys shoot 3-shot groups. Other guys shoot 5-shot groups, or even 10-shot strings. But for testing its projectiles, Sierra Bullets takes it to another level entirely. A while back Sierra was testing its .30-Caliber 175gr HPBT MatchKing in the Sierra underground tunnel. The results appear above — a FIVE HUNDRED Round group!
500 Shots Form 0.82 MOA Group at 300m (328 yards)
Sierra’s trigger-pullers sent five full boxes of bullets down-range at a single target. The photo above shows the result of 500 shots taken in a 300 meter test tunnel. The raw group size, edge to edge of the farthest shots, is about 3.13 inches, as shown on the calipers’ metal linear scale. Subtract a .308″ nominal bullet diameter* to get the 2.823″ on the digital readout. So you’re seeing a 2.823″ group at 300 meters (328 yards). One MOA at this distance is 3.435″ so this 500-round group is 2.823 divided by 3.435 or 0.82 MOA (0.8218 MOA to be precise).
This 500-round group was shoot as part of a pressure/velocity test for a commercial customer. The cartridge was .308 Winchester, loaded at 2.800″. The powder was Reloder 15. A 26″ barrel was shot from a return to battery rest. The gun was cleaned every 125 rounds and two foulers shot.
What do you think — could you beat this group from a bench for 500 rounds?
One Facebook poster joked: “500-round group? Everyone knows anything less than 1000-round groups are a waste of time and statistically irrelevant.”
Sierra’s 300 Meter Testing Tunnel
Ever wonder how (and where) Sierra tests its bullets? The answer is underground, in a 300-meter test tunnel located under Sierra’s factory in Sedalia, Missouri. The photo above shows the construction of the tunnel back in May, 1990. Like most bullet manufacturers, Sierra does live-fire bullet testing of its projectiles. Sierra’s 300-meter test range is the longest, manufacturer-owned underground bullet test facility in the world. In years past, Sierra offered free visits to the test tunnel as part of a factory tour.
* Normally, to get an exact group size, you should subtract the TRUE bullet hole size, which is usually smaller than the nominal bullet diameter. E.g. a .308 bullet hole may show on paper as .298 or so. But here, for simplicity, we are subtracting .308″ because we do not have the original target to measure.
by Sierra Bullets Ballistic Technician Gary Prisendorf
Occasionally someone will ask, “Why did I get a flyer that didn’t go in with the rest of my group?” If I had an answer that would stop flyers from happening, I would be rich.
There are many reasons why this can happen. Everything from gripping a forearm differently to variations in the brass casing, the list goes on and on. Most of the time the flyer is usually shooter induced and sometimes what you may think is a flyer, is just part of your group. There are a lot of shooters, that go out and test a load and they may shoot a 3/8” group at 100 yards and think that load is good. But I have seen far too many times that you can shoot another group, same load, same rifle and the next time you may get a 1 ¼” group.
The total opposite can also occur. You may shoot a 1 ¼” group and turn around and follow it with a 1/2″ group without changing anything. If you only shot the one group, you might decide that load wasn’t any good and move on to something else without really knowing what that load was capable of.
To really determine how a particular load is performing we need to shoot multiple groups and take an average of the group sizes to really see what that rifle/load combination is really capable of.
I suggest shooting a minimum of three 5-shot groups and averaging the group sizes before deciding if the load is acceptable or not. Obviously the more rounds you shoot for a group and the more groups that you shoot, you will get a much better representation of what that particular combination can do.
Now I’m not saying to go out and shoot 30 groups with 50 rounds in each group to determine how well your load is shooting. That would be a bit pointless, in some cases it would be time to re-barrel your rifle before your load development was finished.
In most cases, I feel that three to five, 5-shot groups will give you a pretty good representation of how a load will perform in that specific firearm.
by Sierra Bullets Ballistic Technician Paul Box This cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.
This cartridge was far ahead of its time and for that reason it received a lot of bad press. We’ve all read the horror stories through the years. Many of those stories were just simply repeated from previous articles even the wording was just slightly different. So how bad was the Swift? Let’s take a deeper look.
Some of the early Swifts had soft barrel steel and some of the rare ones even had barrels that were .223 in bore size. This stemmed from the fact that the .22 Hornets prior to the end of World War II were .223 in bore size and some of these barrels were chambered in the Swift. It was rumored that the Swift peaked in pressure far too quick. I’ll bet they did with a turkey extra full choke barrel.
Burn rates of powders were limited at that time as well, so the Swift was limited in its true ability due to that. It was almost like building a funny car for drag racing when only kerosene was available.
One of the longest lasting black eyes was that it shot barrels out so fast. If you get the barrel branding iron hot and fail to clean it often this can happen. Common sense will go a long ways here. Keep the barrel as cool as you can and properly clean it every fifteen rounds or less will go a long way to improving accuracy life of a Swift.
So what is the real truth about this cartridge? I’m glad you ask. I’ve been shooting the .220 Swift for over 43 years now. It is one of the best varmint cartridges I’ve ever owned. It is not hard to load for, it doesn’t suddenly peak in pressure and it isn’t the barrel burner that you’ve heard. Hodgdon powders once reported a Remington 40-X with over 3,000 rounds of full power loads averaged .344” for five, 5-shot groups. My findings have been the same. It isn’t as hard on barrels as it has been made out to be.
I’ve also read that down loading it slightly will help in barrel life. This is true, but if you buy a thoroughbred you want him to run. Barrels are threaded on the end for a reason. If you have enough fun to shoot out a Swift barrel, just rebarrel it.
The bottom line is enjoy the .220 Swift for what it was meant to be. The popularity of the Swift has slipped in the last twenty years and few factory rifles are now available in this caliber. There is no reason for this and I know the Swift will always have a strong and loyal following.
Oversizing cases also causes problems because the firing pin doesn’t have the length to reach the primer solid enough to ignite it 100% of the time. When you have one that is oversized, you usually have a bunch, since you usually do several cases at a time on that die setting. If the die isn’t readjusted, the problem will continue on the next batch of cases also. They will either not fire at all or you will have a lot of misfires. In a bolt action, a lot of time the extractor will hold the case against the face of the breech enough that it will fire. The case gets driven forward and the thinner part of the brass expands, holding to the chamber wall and the thicker part of the case doesn’t expand as much and stretches back to the bolt face. If it doesn’t separate that time, it will the next time. When it does separate, it leaves the front portion of the case in the chamber and pulls the case head off. Then when it tries to chamber the next round, you have a nasty jam. Quite often range brass is the culprit of this because you never know how many times it has been fired/sized and in what firearm. Back to beating it on the ground again till you figure out that you have to get the forward part of the case out.
This cartridge was introduced by Winchester in 1935 in their model 54 rifle. A year later, it was added as a standard cartridge in the model 70. What might not be common knowledge to some reloaders is that the prototype for the Swift was developed in 1934-35 by Grosvenor Wotkyns by necking down the 250 Savage case, but in the end, Winchester chose the 6mm Lee Navy case for the foundation for this cartridge.
