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.
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Sierra Bullets has released extensive load data for the popular 6.5 Creedmoor cartridge. This medium-sized cartridge has become one of the most popular chamberings for tactical and PRS shooters. The 6.5 Creedmoor combines excellent accuracy, good mag-feeding, good barrel life, moderate recoil, and reasonable component cost. That’s why this cartridge has caught on quickly, and is now one of the most popular chamberings in factory rifles.
Developed in 2007 by Dennis DeMille and Dave Emary, the 6.5 Creedmoor is a shortened and improved 30 TC cartridge case that was inspired by the .308 Winchester design. This short action design was created to maximize case capacity and a wide range of loading lengths, while still fitting in standard short action magazines. With the correct twist barrel, the versatile 6.5 Creedmoor can take advantage of the wide range of bullet weights available in 6.5 mm (i.e. .264 caliber). Reloaders should keep in mind that the 6.5 Creedmoor works best with medium to medium-slow powders such as H4350, Varget, Win 760, and RE-17. The light recoil and adaptability of the efficient 6.5 Creedmoor cartridge has already proven itself in high power, precision rifle series and benchrest competitions. Couple that with respectable barrel life and its intrinsic accuracy potential and you have a recipe for success which should insure its legacy for decades to come.
Here are three tables from the Sierra Bullets Reloading Manual (5th Edition). IMPORTANT — This is just a sample!! Sierra has load data for many other 6.5mm bullet types, including FB, Spitzer, SBT, HPBT, and Tipped MK from 85 grains to 142 grains. To view ALL 6.5 Creedmoor DATA, CLICK HERE.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
Two More Great 6.5 Creedmoor Reloading Resources
Want More 6.5 Creedmoor Load Info? View Starline’s 6.5 Creedmoor Guide by Gavin Gear:
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”. CLICK HERE.
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The folks at Sierra Bullets asked a few staff bulletsmiths a classic question about guns: “If you could own only one firearm which one would you choose?” There were many interesting answers including a “cheater” response — the drilling — which is really two guns in one. The most-often mentioned chambering was the venerable .30-06. Respondents cited its versatility, hunting prowess, and ready availability of ammo. The popular .308 Winchester, as expected, got mentions as did its cousins the .243 Win and 7mm-08. There were quite a few votes for classic lever guns, as well as 12-gauge shotguns. Two bulletsmiths cited the .22 LR, and we can certainly see the logic in that answer. The little rimfire cartridge is versatile, quiet, and inexpensive. SEE All Answers.
We ask our readers the same question — if you could only have one long gun, what type of firearm would it be? List the gun type and chambering in the comments section.
If You Could Have Just One Long-Gun — ANSWERS:
Media Relations Manager Carroll Pilant answered: “I would NEVER own only one gun. If I HAD to pick one, it would be a drilling in 12 gauge over .30-06.”
Ballistic Technician Rich Machholz answered: “The early tang safety Ruger M77s pretty much have all you could want in a bolt gun, but I do like the Winchester lever guns and the combination guns, particularly the drillings. Since I have the first two, I’m going for a Doug Turnbull 1886 or a side by side 20 gauge over .223 drilling.”
Ballistic Technician Philip Mahin answered: “More than likely it would have to be a bolt action .30-06. The reliability is legendary on a wide range of game animals and factory ammunition has still been available at my local stores even in these tough times.”
Ballistic Technician Duane Siercks answered: “If I had to boil it all down to one gun, it would probably be a .30-06. I have a Remington 700C (custom shop gun) that has worked very well for anything and everything I have ever wanted to do with it.”
Ballistic Technician Paul Box answered: “A .22 Rimfire.”
Chief Ballistician Tommy Todd answered: “Remington 700 in .308 Winchester.”
VP – Sales & Marketing Matt Reams answered: “A light weight Kimber in 25-06.”
Production Toolsetter Brad Vansell answered: “Savage weather warrior 7mm-08 is my rifle of choice.”
Production Toolsetter Dan Mahnken answered: “The .308 Winchester rifle — [based on the] wide range of bullets made and the wide range of things that one can hunt with it.”
Process Engineer David Palm answered: “Savage action 243 Winchester.”
Ballistic Technician Gary Prisendorf answered: “Probably a .22 LR. It may not be the best choice, but you could use it for about anything if you really had to.”
Production Manager Chris Hatfield answered: “Beretta A300 Outlander 12 gauge.”
by Sierra Bullets Ballistic Technician Paul Box
All of us who have been in reloading and shooting for any period of time have read how sectional density has been regarded as a bullet’s ability to penetrate. Back before high velocity came along and modern bullet design, the easiest way to get more “power” and penetration was by increasing the diameter and mass. After all, a bowling ball will hurt more than a golf ball, right?
Let’s take a closer look at sectional density.
The formula for calculating sectional density is pretty simple and straight forward. Take the bullet weight and divide by 7000. This number is then divided by the bullet diameter squared. Two bullets of equal weight and the same diameter will have equal sectional sectional density. No regard is given to the bullet construction. This is where the fly hits the soup in considering sectional density as far as penetration is concerned.
Section Density Formula: (Bullet Weight divided by 7000) divided by Bullet Diameter squared.
Bullet construction is the biggest factor in how it is able to penetrate. The best example I can think of here is to look at the Sierra .224 55 Gr. FMJBT GameKing #1355 compared to the 55 Gr. BlitzKing #1455. Both are .224 and weigh 55 grs. Both have a sectional density of .157. But there is a huge difference in their construction. The FMJ has a thick jacket and is designed to penetrate. The BlitzKing is designed for fast and rapid expansion with little concern for how deep they will penetrate.
The next time you’re choosing a bullet, look at the construction and less at the sectional density number. It’s all about the construction anyway. If you have any questions or would like to discuss sectional density or bullet penetration further, please give us a call at 800-223-8799 or shoot us an email at sierra@sierrabullets.com.
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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.
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Here are some really smart tips for hand-loaders compiled by Sierra Bullets. These suggestions were submitted by Sierra’s Facebook fans — and some are very valuable indeed. Some of these tips will help you load more accurate ammo. Other selections will help you stay SAFE — which should always be your #1 priority. For example, we concur with the advice to “Check and Double Check. Everything. Every Time”. Also definitely keep “One powder on the bench at a time” — that could be a life-saver. You may want to print these “words of wisdom” and place them on a wall in your loading room.
Reloading Safety Tips — Sound Advice
ALWAYS START LOW: “Just because a load manual says X grains of X powder with X bullet is max, your rifle could reach max pressure a grain or two before what the book says. Start low and work up.” — Walter Coats
BE SAFE and CAREFUL: “Check and double check. Everything. Every time. Only one type of powder on the bench at a time.” — Glen Lundgren
DON’T RUSH: “Be patient, don’t be in a hurry, have fun and find your rhythm. Just tell your family you’re putting yourself in ‘time-out’. They will understand.” — Erik Dyal
POWDER RULE #1: “One powder on the bench at one time, it might save your life.” — James A. Kimery
STAY FOCUSED: “Relaxed but concentrated attention. Have fun enjoying a great hobby and pastime but stay focused.” — Jim Caldwell
POLICE LOADING AREA: “Keep your reloading bench area clean and put items away ASAP.” — Eric J. Ford
BE PATIENT: “Focus, Focus, Focus — be patient — it AIN’T a race.” — William Stanley
RECORD YOUR LOADS: “Write down on a small card what you’re loading – bullet weight, powder weight, type of powder, and primer. And put it in the powder hopper. I am unloading .45 FMJ because I forgot what type powder was in the hopper.” — Michael Conniff
HAVE a PROCEDURE for INTERRUPTIONS: “If, for any reason, you have to leave the bench while in the process of dropping powder charges, turn the next case to be charged upside down in the loading block so you know where you left off.” — Bill Tinsley
LABEL EVERYTHING: “OCD is a good habit to have with your loading bench. CLEARLY label everything!” — Andy Pynckel
HAVE a GOAL: “Never start reloading or developing a load without a specific goal in mind. Second keep meticulous records.” — Peter Eick
RESEARCH THE JOB: “Read all you can about it before you start!” — Keith Shively
KEEP TRACK of the Brass: “I put all my primed brass upside down (primer up) and as I charge the casing, I (of course) flip it primer down.” — Mark Ewing
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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.
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Need some informative reading material for winter days? Here’s a vast resource available free from Sierra Bullets. Here are links to over 60 articles with information on bullets, ballistic coefficients, wind drift, up/down angles, temperature effects, tailwind effects and much more. Most of these resources come from the respected Sierra Reloading Manuals, 4th and 5th Editions. There are enough articles to read one per week for a year!
Sierra Bullets has released extensive load data for the popular 6.5 Creedmoor cartridge. This medium-sized cartridge has become one of the most popular chamberings for tactical and PRS shooters. The 6.5 Creedmoor combines excellent accuracy, good mag-feeding, good barrel life, moderate recoil, and reasonable component cost. That’s why this cartridge has caught on quickly, and is now one of the most popular chamberings in factory rifles.
Developed in 2007 by Dennis DeMille and Dave Emary, the 6.5 Creedmoor is a shortened and improved 30 TC cartridge case that was inspired by the .308 Winchester design. This short action design was created to maximize case capacity and a wide range of loading lengths, while still fitting in standard short action magazines. With the correct twist barrel, the versatile 6.5 Creedmoor can take advantage of the wide range of bullet weights available in 6.5 mm (i.e. .264 caliber). Reloaders should keep in mind that the 6.5 Creedmoor works best with medium to medium-slow powders such as H4350, Varget, Win 760, and RE-17. The light recoil and adaptability of the efficient 6.5 Creedmoor cartridge has already proven itself in high power, precision rifle series and benchrest competitions. Couple that with respectable barrel life and its intrinsic accuracy potential and you have a recipe for success which should insure its legacy for decades to come.
Here are three tables from the Sierra Bullets Reloading Manual (5th Edition). IMPORTANT — This is just a sample!! Sierra has load data for many other 6.5mm bullet types, including FB, Spitzer, SBT, HPBT, and Tipped MK from 85 grains to 142 grains. To view ALL 6.5 Creedmoor DATA, CLICK HERE.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
INDICATES MAXIMUM LOAD – USE CAUTION
LOADS LESS THAN MINIMUM CHARGES SHOWN ARE NOT RECOMMENDED.
Two More Great 6.5 Creedmoor Reloading Resouces
Want More 6.5 Creedmoor Load Info? View Starline’s 6.5 Creedmoor Guide by Gavin Gear:
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”. CLICK HERE.
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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.
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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.
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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.
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NOTE: There are ten (10) shots in the group, but for simplicity we are only displaying five (5) shot circles. Adding more circles won’t change the measurement because the two most distant shots, which determine group size, ARE included.
What kind of 200-yard accuracy can you get in an enclosed, underground test range? Would you believe 0.162 MOA at 200 yards with a .338? Have a look at these test targets from Sierra Bullets. Like most bullet manufacturers, Sierra does live-fire bullet testing to ensure that Sierra projectiles perform as promised, with repeatable accuracy. Sierra tests bullets in its own underground test complex. Sierra’s 300-meter test range is the longest, privately-owned underground bullet test facility in the Western Hemisphere.*
Day in and day out, various bullet types are tested using a big collection of barreled actions. These barreled actions are clamped in stout, return-to-battery test fixtures. These big, heavy test fixtures provide near-perfect repeatability (with no human-induced holding or aiming errors).
Sierra Bullets 10-Shot Groups at 200 yards
Check out these 10-shot test groups shot at the Sierra Test Range at 200 yards. Note that the numbers listed on each sample are actual measurements in inches. To convert to MOA, cut those numbers in half (to be more precise, divide by 2.094, which is 1 MOA at 200 yards). For example, the 0.340″ middle group works out to 0.162 MOA at 200 yards.
Scan-Verified 0.162 MOA Accuracy at 200 Yards
To verify the accuracy of Sierra’s measurements, we measured the middle (.338 caliber) 10-shot group with our On-Target Group Measurement software. We registered a group size reading of 0.339″ — within one-thousandth of the Sierra measurement. The calculated group size in MOA (Minute of Angle) is 0.162.
That’s amazingly good for ten rounds of big .338 caliber bullets. A FIVE-shot 0.162 MOA group at 200 would be considered excellent at any benchrest match. But remember this target has TEN shots. The current, one-target IBS world record for ten shots at 200 yards is 0.245″, set by Ed Watson in 1999.
Bevy of Barreled Actions for Bullet Testing
Sierra Bullets uses dozens of barreled actions for testing bullets in its enclosed, 200-yard test range. Each barrel has its own logbook to track the barrel’s usage.
Click Photo to Zoom
*Even Longer Test Tunnels Exist in Europe: At Stadeln in Germany, RWS (now part of RUAG) owns a 500 meter tunnel (above ground level) which has existed for decades. In Thun, Switzerland, RUAG has a fully-instrumented 500 meter underground tunnel. Near Ulm, Germany, there is a 5-lane 300 meter underground shooting range that is open to the public.
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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.
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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.
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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.
Developed in 2007 by Dennis DeMille and Dave Emary, the 6.5 Creedmoor is a shortened and improved 30 TC cartridge case that was inspired by the .308 Winchester design. This short action design was created to maximize case capacity and a wide range of loading lengths, while still fitting in standard short action magazines. With the correct twist barrel, the versatile 6.5 Creedmoor can take advantage of the wide range of bullet weights available in 6.5 mm (i.e. .264 caliber). Reloaders should keep in mind that the 6.5 Creedmoor works best with medium to medium-slow powders such as H4350, Varget, Win 760, and RE-17. The light recoil and adaptability of the efficient 6.5 Creedmoor cartridge has already proven itself in high power, precision rifle series and benchrest competitions. Couple that with respectable barrel life and its intrinsic accuracy potential and you have a recipe for success which should insure its legacy for decades to come.
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.
Scan-Verified 0.162 MOA Accuracy at 200 Yards
