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December 3rd, 2024
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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November 19th, 2024
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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October 10th, 2024
NOTE: The 6mm Creedmoor now does have an official SAAMI specification. It is no longer just a wildcat.
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) |
80gr SBT (#1515)
85gr Spitzer (#1520)
85gr HPBT (#1530)
90gr FMJBT (#1535)
95gr HPBT (#1537) |
95gr TMK (#7295)
100gr Spitzer (#1540)
100gr SBT (#1560)
107gr HPBT (#1570)
110gr HPBT (#1575) |
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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September 3rd, 2024
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.
To see more examples, view both Part I and Part II of the Case Diagnostics from Sierra Bullets:
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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August 8th, 2024
Photo by Forum member R. Hardy. View Related Accurate Shooter Forum Thread.
It’s summertime, 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.
[One summer] 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.
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July 28th, 2024
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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July 15th, 2024
Adam Scepaniak, of The Guns and Gear Store, has written an interesting story about Prairie Dog Hunting in North Dakota. If a P-Dog safari is on your “bucket list”, you’ll want to read the full story in the Sierra Bullets Blog. Adam provides many tips that can help you plan a successful prairie dog adventure.
Prairie Dog Hunting in North Dakota with Sierra Bullets
It’s that time of year where lots of men and women point their vehicles westward and try to push the limits of their rifles on prairie dogs. [A few seasons back] I was a part of this group of people… while in northwestern North Dakota. CLICK HERE to Read Full Story.
 Little Missouri National Grassland
Once my hunting party arrived at the Little Missouri National Grassland in North Dakota we immediately began scouting for prime prairie dog towns. There is a certain amount of strategy involved in choosing a prairie dog town … for several reasons. For one, you should try to always stay “above” the prairie dogs.
Small objects like rocks, cactuses, and prairie vegetation can easily obstruct your view if you’re shooting prone on a level plane. We encountered this in the first small prairie dog town we stopped and shot at. The prairie dog town was very visible while walking and standing, but once we laid down with our rifles on bipods the two-foot prairie grass became a severe obstruction. We shortly moved on because the small town became quick-studies to our shooting.
The second prairie dog town we hunted was at the base of a small ridge with a dried, cattle creek at the bottom. This area offered better shooting opportunities because we were above most of the prairie dog holes, and if we were not above them, a deep ravine separated us from the prairie dogs removing any obstructions from our rifle scopes which was our previous problem. This area had its own disadvantage though because of some other wildlife present. There were approximately fifty head of cattle in our close vicinity grazing, which was to no surprise because many ranchers utilize the National Grassland for grazing. We had to wait for the cattle to leave our area as to not have an incidental hit due to a rare ricochet. As the sun passed over the horizon we decided to return to this spot the next morning, but would change our shooting position to increase our advantage.
This Location Offered a Nice Overlook.
Zoomed Image Shows Individual Prairie Dog Mounds.
My previous varminting best was a 275-yard shot near Mobridge, South Dakota on a separate prairie dog hunting trip. With more experience and better reloading, Here in North Dakota I was able to make a solid hit on a prairie dog just over 400 yards which made me ecstatic! For a central Minnesota, shotgun-raised guy, I was pretty happy that my bullet selection and hand-loading ability produced a 125-yard improvement.
Once we cleaned and cased our rifles for the journey home we had shot a little over 200 rounds of my Sierra® reloads. This was a lot less than previous prairie dog trips I have been a part of, but our hit percentage was substantially higher as well. Traveling into a new area meant a lot more scouting and experimentation for us as a group. In future trips or hunts of your own, it can be very beneficial to schedule an extra day just for scouting[.]
Little Missouri National Grassland is a National Grassland located in western North Dakota. At 1,033,271 acres, it is the largest grassland in the country. Within its borders is Theodore Roosevelt National Park. The Little Missouri National Grasslands was once a part of the Custer National Forest, but is now a part of the Dakota Prairie Grasslands, a National Forest unit consisting entirely of National Grasslands. A predominant feature of the grassland is colorful and beautiful badlands, a rugged terrain extensively eroded by wind and water. It is a mixed grass prairie, meaning it has both long and short grass.
The boundaries of the grasslands on certain maps can be misleading. Within the boundaries of the national grassland are significant portions of state-owned and privately-owned land, much of it leased by cattle ranchers for grazing.
The grassland is administered by the Forest Service as part of the Dakota Prairie Grasslands from offices in Bismarck, ND. There are ranger district offices in Dickinson and Watford City.
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July 3rd, 2024
Understanding Twist: Bullet Stabilization
by Sierra Bullets Ballistic Technician Paul Box for Sierra Bullets Blog.
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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June 13th, 2024
Here’s something you don’t see every day — a reloading press that has loaded over 1,000,000 rounds of ammo. At the NRA Convention in Dallas in 2018, Redding showcased an old Redding T-7 Turret Press delivered to Sierra Bullets decades ago. 0ne of the very first T-7s made by Redding, this “old warrior” was used by Sierra Bullets to load over 1,000,000 rounds of ammunition in Sierra’s ballistics lab.
 Redding T-7 Still Within Spec
After all that loading, Redding tested the press and, remarkably, found that it still remained “within spec”. Redding notes: “This press was subjected to real world reloading wear and stress yet remains within ‘new’ spec after this historic test”. When showcased in Dallas, this Redding turret press was fitted with indicators to show “just how good American steel and craftsmanship remains after what, in a normal situation, would represent numerous lifetimes of use.”
The Redding T-7 now has major turret press rivals — the Lyman All-American 8-station press, and the Area 419 9-station ZERO Turret Press. That $1275 ZERO Turret is generally regarded as the most sophisticated turret press ever created.
 About Redding Reloading
Redding Reloading Equipment has crafted quality, American-made products for the precision handloading market since 1946. Along with single-stage and turret presses, Redding makes great dies. And Redding’s line of tools/accessories includes concentricity gauges, scales, trimmers, powder measures, powder tricklers, cleaning tools, deburring tools, bushings, and many other quality items.
To learn more about Redding products you can download the latest Redding Catalog in PDF format, or visit Redding-Reloading.com. You can also request a free Redding Printed Catalog.
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May 30th, 2024
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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May 28th, 2024
NOTE: The 6mm Creedmoor now does have an official SAAMI specification. It is no longer just a wildcat.
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) |
80gr SBT (#1515)
85gr Spitzer (#1520)
85gr HPBT (#1530)
90gr FMJBT (#1535)
95gr HPBT (#1537) |
95gr TMK (#7295)
100gr Spitzer (#1540)
100gr SBT (#1560)
107gr HPBT (#1570)
110gr HPBT (#1575) |
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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April 2nd, 2024
by Sierra Bullets Ballistic Technician Paul Box
One thing that plays a major role in building an accuracy load is neck tension [one of the factors that controls the “grip” on a bullet]. I think a lot of reloaders pretty much take this for granted and don’t give that enough thought.
So, how much neck tension is enough?
Through the years and shooting both a wide variety of calibers and burn rates of powder, I’ve had the best accuracy overall with .002″ of neck tension. Naturally you will run into a rifle now and then that will do its best with something different like .001″ or even .003″, but .002″ has worked very well for me. So how do we control the neck tension? Let’s take a look at that.
First of all, if you’re running a standard sizing die with an expander ball, just pull your decapping rod assembly out of your die and measure the expander ball. What I prefer [for starters] is to have an expander ball that is .003″ smaller than bullet diameter. So for example in a .224 caliber, run an expander ball of .221″. If you want to take the expander ball down in diameter, just chuck up your decapping rod assembly in a drill and turn it down with some emery cloth. When you have the diameter you need, polish it with three ought or four ought steel wool. This will give it a mirror finish and less drag coming through your case neck after sizing.
Tips for Dies With Interchangeable Neck Bushings
If you’re using a bushing die, I measure across the neck of eight or ten loaded rounds, then take an average on these and go .003″ under that measurement. There are other methods to determine bushing size, but this system has worked well for me.
Proper Annealing Can Deliver More Uniform Neck Tension
Another thing I want to mention is annealing. When brass is the correct softness, it will take a “set” coming out of the sizing die far better than brass that has become too hard. When brass has been work hardened to a point, it will be more springy when it comes out of a sizing die and neck tension will vary. Have you ever noticed how some bullets seated harder than others? That is why.
Paying closer attention to neck tension will give you both better accuracy and more consistent groups.
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