A while back, Sinclair International’s Reloading Press Blog featured a “round-table” discussion of reloading techniques. Sinclair’s team of tech staffers were asked: “What do you feel is the one-most crucial step in precision reloading?”
Here are their responses (along with comments from our Editors):
Phil Hoham: “I feel that when working up a load do not go too high or too low in your powder charge. Stay away from ‘suggested loads’ you hear at the range, or on the internet. Always be sure to use a published reloading manual that presents not only minimums and maximums, but also pressure, velocity, and a proper range of powders used. Do not get distracted in the reloading process, and remain focused at all times during each step involved.”
AccurateShooter.com: Some loads presented on the Internet are OK as a starting point, but it is absolutely critical to understand that pressure maximums will vary considerably from one rifle to another (of the same chambering). For example, one 6mmBR rifle shooting 105gr bullets can max out with 30.0 grains of Varget powder, while another rifle, with the same chamber dimensions, but a different barrel, could tolerate (and perform better) with half a grain more powder. You need to adjust recommended loads to your particular rifle and barrel.
Pete Petros: “This could be a very broad topic, but if I were to pick one, it would be making sure to pay close attention, and weigh each and every powder charge to ensure that each load is exact and consistent. This is important not only for accuracy, but also for safety reasons.”
AccurateShooter.com: If you’re shooting beyond 200 yards, it is critical to weigh your loads with an accurate scale or automated system such as the AutoTrickler V3/V4. Loads that are uniform (within a few kernels) will exhibit lower Extreme Spread and Standard Deviation. And remember, even if you stick with the same powder, when you get a new powder lot, you may have to adjust your load quite a bit. For example, .308 Palma shooters have learned they may need to adjust Varget loads by up to a full grain from one lot of Varget to the next.
Ron Dague: “I feel that the most important step(s) in reloading for accuracy are in the initial case prep. Uniforming the primer pocket to the same depth to ensure consistency in primer seating is a crucial step. Additionally de-burring the flash holes, each in the same way to clean up and chamfer the inside is important. It ensures that the ignition from the primer is uniform and flows out in the same consistent pattern. Doing so will create uniform powder ignition and tighten up your velocity Extreme Spread.”
AccurateShooter.com: With some brands of brass, primer pocket uniforming and flash-hole deburring is useful. However, with the best Lapua, Norma, and RWS brass it may be unnecessary, or worse, counter-productive. So long as your Lapua brass flash-holes are not obstructed or smaller than spec, it may be best to leave them alone. This is particularly true with the small flash holes in 220 Russian, 6BR, and 6.5×47 cases. MOST of the flash-hole reaming tools on the market have cutting bits that vary in size because of manufacturing tolerances. We’ve found tools with an advertised diameter of .0625″ (1/16″) that actually cut an 0.068″ hole. In addition, we are wary of flash-hole deburring tools that cut an aggressive inside chamfer on the flash-holes. The reason is that it is very difficult to control the amount of chamfer precisely, even with tools that have a depth stop.
Rod Green: “I feel that bullet seating is the most important step. If you had focused on making sure all prior steps (case prep, powder charge, etc.) of the process have been carefully taken to ensure uniformity, bullet seating is the last step, and can mean all the difference in the world in terms of consistency. Making sure that the bullet is seated to the same depth each time, and time is taken to ensure that true aligned seating can make the load.”
Bob Blaine: “I agree with Rod. I strongly feel that consistent bullet seating depth is the most important step in creating the most accurate hand loads. I have seen the results in both my bench and long range rifles. Taking the time to ensure exactness in the seating process is by far, the number one most important step in my book.”
AccurateShooter.com: Agreed. When loading match ammo, after bullet seating, we check every loaded round for base of case to ogive length. If it varies by more than 3 thousandths, that round is segregated or we attempt to re-seat the bullet. We measure base of case to bullet ogive with a comparator mounted on one jaw of our calipers. You may have to pre-sort your bullets to hold the case-base to ogive measurement (of loaded rounds) within .003″.
The 600-yard target has an X-Ring 6 inches (1 MOA) across, while the 10-Ring spans 12 inches (2 MOA).
The following article is about reloading for NRA/CMP Highpower Rifle competition and is geared toward competitors shooting the AR15 Service Rifle. In Highpower Rifle competition, shooters fire in four stages: Standing slow-fire at 200 yards, Sitting rapid-fire at 200 yards, Prone rapid-fire at 300 yards, and Prone slow-fire at 600 yards. Competitors use a sling for support in all positions but standing. A typical AR15 Service Rifle sports a 20″ free-floated barrel and a 4.5-pound trigger. Service Rifle scopes are limited to maximum power of 4.5X.
Thoughts on Loading for Service Rifles, Particularly for 600 Yards
by Danny Arnold, Team CMP Article originally published in CMP Shooting News
Before we get started, I want to stress that all of the information that follows is geared toward the .223/5.56 Service Rifle. That doesn’t mean that there’s nothing here for anyone else, but the .223/5.56 Service Rifle platform is where I’ve spent the majority of my time, so here we go.
There is only one “Perfect” 600–yard load for my rifle, True or False? This example is more anecdotal than scientific, but it provides some food for thought….
Team CMP spent the early part of March competing in the Orange Blossom Regional. As soon as we got on the range, Sara Rozanski (Team CMP member) started having problems with her 600-yard ammunition. Nearly 1/3 of her cases were exiting the chamber minus the primers. I offered to swap my ammunition for hers, suspecting that my Wylde chamber would be more forgiving than her CLE chamber — a solution that seemed to solve the problem. At least neither of us was blowing primers!
Sara’s ammunition was a factory load using a well-known 80+ grain bullet with an unknown primer and powder, using brass from a respected manufacturer. My load was a different brand of 80-grain bullet, with my choice of powder and primer, all in brass made by someone else. Given the color of the primers, the only thing that our ammunition could possibly have had in common was the brand of powder… maybe. So, how did we shoot?
Sara and I shot the two-person team together and the entire 2,400 Aggregate, although on different relays. Sara’s combined 600-yard score was 780-28X (97.5%). Mine was a 783-24X (97.87%). Our scores were never more than two points apart on any of the four days. Keep in mind that we were using each other’s ammunition the entire time.
So, we had different barrels, chambers and ammunition, but similar results. That goes back to the idea that a good load will perform similarly if fired in a good barrel.
Are We Too Focused on Ballistic Coefficients (BCs)?
The revailing wisdom has always trended toward loading the highest-BC bullet we could find and pushing it as fast as possible. Back in the early ’90s when I got started with the AR15, the 80-grain Sierra was state of the art. Actually, I picked up all of my Leg points with it, although today it looks a bit dated — kinda like me.
So, the question I’ll pose is this: Would you rather shoot a high-BC bullet that groups 3/4-MOA (minute of angle) or a lower-BC bullet that groups into one-half-MOA traveling 50 feet-per-second faster? The reason that I posed this question is a situation I found myself in a decade ago. Our coach decided that he wanted us to pair-fire some 600-yard for practice. Unfortunately, I hadn’t gotten the memo and all that I had available was my normal short-line ammunition, loaded with a 77-grain bullet. The shooter I was paired with was using a higher-BC bullet than I was, but in the end, we both shot 198s.
Admittedly, using 77-grainers meant that coach had to work a little harder to keep us together on target, but it was a teaching moment for me. I knew that my upper shot 77s better than the available bullets in the 80-grain range, so I cranked out a windage table for the 77-grain bullet at 600 yards and shot those for the rest of the season. After all, the wind blows ALL bullets around. It’s just a matter of knowing what YOUR bullet is doing.
With the shortages that we’re experiencing right now, a lighter bullet may be all that you have available for the 2021 season. That doesn’t mean that you’re disadvantaged though.
Danny Arnold teaching Highpower Clinic at 2021 CMP Eastern Games
Loading High-BC Bullets
In the past decade, several bullets have appeared that weigh 80-grains or more. One thing that many of them have in common is a very sharp nose profile, whether metal or polymer. The question is: Are you using the right seating stem?
The jacket material in the bullet’s nose is very thin. If you section a bullet, you’ll find that there is a surprising amount of air space in the nose. If you’re using older seating dies, your seating stem may be contacting the bullet nose too close to the tip, where the jacket is the both thinnest and is unsupported by the lead core. This can manifest itself either as a deformation at the very tip of the bullet or as a circular dent around the bullet nose that you can see and feel with your thumbnail. I think we can all agree that denting a bullet is usually considered a bad thing.
One company goes so far as to recommend their proprietary seating stem for use with their high-BC bullets. Other companies leave it up to you to find a seating stem that will allow the bullet nose to go deeper into the seating stem, moving the contact point further down the bullet where the jacket is thicker and supported by the core material.
Seating Depth and Bullet Preferences
Some bullets don’t mind some “jump” into the lands, but some really do. Unfortunately, manufacturers don’t tell you much about that. Your chamber configuration (Wylde, CLE, or some hybrid of the two) and the bullet that you choose will determine your optimal seating depth. Long and short of it, a quality measuring tool to determine seating depth is a necessity these days. Keep in mind that if you’re doing this with a brand new barrel, the throat is likely going to change slightly in the first 200 rounds and may need to be re-measured. Actually, since all of your short range ammunition has to be loaded to magazine length, you’re probably better off developing your short range loads before starting on long range load development. That gives the throat a chance to wear in a bit on a new barrel.
Brass Prep — Why It Is Important
When match-grade AR15s first arrived on the scene, it was amazing how little it took to get them to shoot well. Other than making sure that I had brass from the same lot and running it through a set of match-grade dies, I did nothing. Of course, we were also using a post front sight. Was the occasional bad shot me, the rifle, the load or just an archaic sighting system?
Transitioning to optics has caused me to reconsider how and what I do in my reloading process: That, and having some extra time on my hands to experiment.
A little (or a lot) of time spent with a neck turning tool, a primer-pocket uniformer and a flash-hole reamer will quickly show you how consistent brass is by manufacturer and even by individual lot. That exercise also makes the prices charged for high-quality brass seem ridiculously cheap. That doesn’t mean that I advocate neck-turning or other uniforming practices, nor do I advocate spending scandalous amounts of money on long-range brass. However, our sport is about consistency. The consistency of your brass is a matter of choice, whether you choose to simply segregate cases by weight (cheap option), neck turn (labor intensive) or open your wallet a little wider for premium brass.
Weighing Charges vs. Throwing with Powder Measure
To measure or weigh? For a long time, I used a powder measure to throw all of my 600-yard loads. The powder I was using metered well, and the results downrange didn’t justify the extra time spent with a scale. That was in the day of iron sights though. Nowadays, I’m throwing my charges and trickling up to the desired weight as measured on a scale that weighs to a 100th of a grain.
To quantify the difference between individually weighing each charge versus throwing charges with a powder measure, I weighed six kernels of powder that I trickled into the pan and then dumped them into the hopper. Going through that process 10 times, I came up with an average weight of .08 grains for six kernels. Next, I threw 50 charges for weighing using my powder measure. If I felt the measure hanging up as it cut kernels, I put the charge back into the hopper without weighing it.
That’s six kernels of powder sitting in the pan — average weight .08 grains.
Those 50 smoothly-thrown charges varied .26 grains from lowest to highest, with the majority varying no more than .16 grains from highest to lowest. If the desired weight was exactly in the middle, at worst you’d be .13 grains (9-10 kernels) low or high, with the majority being off no more than .08 grains (6 kernels) above or below the desired charge weight. Is that enough to send a shot outside the 2-MOA 10-Ring? Probably not.
Has more consistent brass and weighing charges to one-hundredth (0.01) of a grain added up to higher scores? Honestly, this question is hard to answer. Looking at the results on paper at 200 yards, using a powder that meters well combined with a consistent touch on the loading lever doesn’t appear measurably different than meticulously weighing each and every powder charge. Looking back over my 600-yard plots however, I can see a trend toward a group that is closer to X-Ring height.
Since the bullseye is widest at the center, shooting groups that are the height of the X-ring gives you more room for error when the wind is blowing. That can translate into higher 600-yard scores.
How You Load Your Ammunition vs. How You Load Your Rifle
The loading/chambering cycle of the AR-15 is, in a word, violent. You have a relatively heavy bolt and carrier assembly under power of a stout buffer spring slamming forward to chamber each round of ammunition. By design, those rounds were supposed to be held securely by the magazine feed lips until the bolt stripped them off the follower. Obviously, due to their overall length, 600-yard loads can’t be chambered that way. Although the barrel extension is funnel-shaped, it’s also got a lot of “teeth” ringing the inside of it (see below).
Whether you’re using a standard magazine or a single-round loading device (SLED), dropping a round in the loading port and releasing the bolt is an act of faith in that you’re trusting the bullet to arrive in the chamber undamaged.
Ask yourself, how many times have you seen someone drop a round on the follower, press the bolt release and watch as the bolt jammed on a cockeyed round? If that happens once every 100 tries, how many times did the bolt close on a scratched, dented, or misaligned bullet? Could that be the cause of the occasional errant shot?
My technique is to drop each round on top of the SLED and then push it slightly forward with my finger, partially chambering it before releasing the bolt. Admittedly, some people may be unable to do this due to body configuration or left-handedness, but why go to all the trouble of loading “perfect” ammunition and then damage it on the way into the chamber?
Now that we’ve covered bullets, brass, and assorted errata we can move on to discussing loads for 600 Yards…
The NRA Highpower 600-yard target has a 6-inch (1 MOA) X-Ring, and a 12-inch (2 MOA) 10-Ring.
Load Development for 600 Yards
Finding a load for 600 yards is a lot like finding a load for short range. Once I decide on a bullet, powder, primer, velocity range and a measured guesstimate of seating depth, I load 10 rounds of each test load, increasing in 0.2 (2/10) grain increments. I test them from the prone position at 200 yards. Ideally, I want to see two loads that are 0.2 (2/10) of a grain apart that shoot almost identical groups. The load that I choose will fall in between the two best shooting loads that I tested. If the first load is XX.2 grains and the second is XX.4 grains, my chosen load will be XX.3 grains.
Why develop loads in 0.2-grain (tenths) increments if I have a scale that measures in 0.01-grain (hundredths) increments? Or, why not test in 0.1-grain increments?
For me, working in 0.2-grain increments gets me to the results quicker. Also, there is a difference between accuracy and consistency in this scenario. Developing loads in 0.2-grain increments gets me to an accurate load. Producing that load using a scale that accurately measures to .01-grain insures a consistent load, assuming that I do my part.
Once I’ve settled on a load, it’s time to play with seating depth, if I choose to. If I’m lucky and the groups are acceptable as-is, I won’t do anything. If I think there’s room for improvement, I’ll experiment a little. Depending on the bullet, changing the seating depth by a couple of thousandths one way or the other may change the group size. During this phase of testing, it’s a good idea to chamber a round and see if the entire round will then extract. If you leave a bullet stuck in the throat, your rounds are too long. Finding that out at a match can ruin an otherwise good day.
Danny Arnold shooting his AR15 Service Rifle, standing position at 2021 CMP Eastern Games.
Another thing to keep in mind is that your barrel is not static. Every round fired has an effect on the throat, vaporizing and scouring away metal until the distance the bullet travels before meeting the rifling measurably increases. If you have chosen a bullet that shoots best when close to the lands, you’ll need to periodically re-measure and possibly change your bullet seating depth to maintain that optimal relationship.
The Elephant in the Room — User Skill Level
There’s really not a delicate way to put this, so I won’t try. There’s little point in spending time and effort developing a load that shoots into half-MOA off the bench if you’re only capable of shooting 2 MOA using a sling right now.
That doesn’t mean that there’s no hope. On the contrary, it just means that your time and effort is better spent practicing with some good short-range ammunition on reduced targets at a 100 or 200-yard range. At that distance, wind is not a factor and your technique can be improved more quickly so you’re in a position to benefit from that ½ MOA ammunition.
About Team CMP
CMP has created a Highpower Team with top competitors. Team CMP competes at several events throughout the year and most importantly, helps to teach Highpower Clinics at CMP Competition Events. Learn from Team CMP at Camp Perry during the Advanced Highpower Clinic, scheduled this year for July 30 through August 1, 2021. Visit the Highpower Clinic Web Page for more information.
The Civilian Marksmanship Program is a federally-chartered 501(c)(3) non-profit corporation. It is dedicated to firearm safety and marksmanship training and to the promotion of marksmanship competition for citizens of the United States. For more information about the CMP and its programs, visit www.TheCMP.org.
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.
The anvil is the tripod-shaped thin metal piece protruding above the bottom of the primer cup. Getting the primer sitting fully flush on the bottom of the case primer pocket, without crunching it too much, requires some keen feel for the progress of primer seating.
Sadly, Glen Zediker passed away in October 2020. However, his insights live on through his written works. This feature is based on Glen’s popular reloading books and his articles for the Midsouth Blog.
In two informative Midsouth Blog articles, Glen Zediker offers helpful advice on priming. First he examines what happens to the primer itself as it is seated in the cup. Glen explains why some “crush” is important, and why you never want to leave a high primer. Glen also reviews a variety of priming tools, including his favorite — the Forster Co-Ax Bench Primer Seater. Then he offers some key safety tips. Glen provides some “rock-solid” advice about the priming operation. You’ll find more great reloading tips in Glen Zediker’s popular book, Top-Grade Ammo, which we recommend.
Priming Precision vs. Speed
Glen writes: “The better priming tools have less leverage. That is so we can feel the progress of that relatively very small span of depth between start and finish. There is also a balance between precision and speed in tool choices, as there so often is.”
Benchtop Priming Tools — The Forster Co-Ax
Glen thinks that the best choice among priming options, considering both “feel” and productivity, may be the benchtop stand-alone priming stations: “They are faster than hand tools, and can be had with more or less leverage engineered into them. I like the one shown below the best because its feeding is reliable and its feel is more than good enough to do a ‘perfect’ primer seat. It’s the best balance I’ve found between speed and precision.”
Load Tuning and Primers
Glen cautions that you should always reduce your load when you switch to a new, not-yet-tested primer type: “The primer is, in my experience, the greatest variable that can change the performance of a load combination, which is mostly to say ‘pressure’. Never (never ever) switch primer brands without backing off the propellant charge and proving to yourself how far to take it back up, or to even back it off more. I back off one full grain of propellant [when I] try a different primer brand.”
Priming Safety Tips by Zediker
1. Get a good primer “flip” tray for use in filling the feeding magazine tubes associated with some systems. Make double-damn sure each primer is fed right side up (or down, depending on your perspective). A common cause of unintentional detonation is attempting to overfill a stuffed feeding tube magazine, so count and watch your progress.
2. Don’t attempt to seat a high primer more deeply on a finished round. The pressure needed to overcome the inertia to re-initiate movement may be enough to detonate it.
3. Don’t punch out a live primer! That can result in an impressive fright. To kill a primer, squirt or spray a little light oil into its open end. That renders the compound inert.
4. Keep the priming tool cup clean. That’s the little piece that the primer sits down into. Any little shard of brass can become a firing pin! It’s happened!
Here is an important safety reminder for readers who employ hand priming tools with trays of multiple primers. In this instance a primer detonated while being seating in a pistol cartridge case. This caused a “flash-over” which instantly ignited multiple other primers in the tray. That, in turn, caused a small explosion which broke the tray and Hornady Handheld Priming Tool. The user, a Forum member, reported this last summer in our Shooters’ Forum.
Report by Forum Member about Primer Flash-Over Incident
I had a small scare the other day while reloading. My experience might be a helpful reminder to people to keep safe and follow proper procedures and not be sloppy.
A primer popped (went off) when being seated and (while hot) flashed over into the tray causing other primers in the tray to detonate. That, in turn, broke my Hornady Handheld Priming Tool and injured my hand.
Here is my loading area after the incident. Note the damage to the hand priming tool. I’m not not sure where the rest of the pieces are.
Injuries to User — Multiple Cuts on Hand and Forearm
This photo shows the resulting cuts to hand. Fortunately they seem superficial. Note — I was wearing latex gloves so my hand had some protection.
The blast also blew my glasses off my face and they landed about six feet away. Be careful folks and wear your eye protection! EDITOR: Guys — This is yet more compelling evidence why handloaders should always wear eye protection!
More Details — Primers Were Federal LP, Case Primer Pockets Had Been Checked
The forum member noted: “Just in case people are interested, I didn’t notice anything different from usual. Cases were Privi Partizan (PPU) factory brass on their fourth firing. The primers were Federal Large Pistol. The cases had been ultrasonic cleaned and the primer pockets checked prior to priming. I had primed around 50 cases during this session before the accident.”
Here is a close-up of “flashed” primers — note the empty but dented cups and triangular “anvils”:
Two other Forum members reported feeding issues with this particular Hornady handheld priming tool and one other member, Kiwi Greg, suffered a multi-primer detonation causing injury: “I had the same thing happen a few years ago now with the same Hornady hand primer with 50-75 [Federal 215M primers] in the tray. Made a bit of a mess of both my hands, blew primers and tray all around my large workshop. Scared the [heck] out of my employee who was near me at the time. Some stitches, bandages and it was all good, [but with] some wicked scars… I think a primer had turned side-on when being put into Bertram .408 CT brass which had nice tight pockets and required more force than usual. I use RCBS [priming tools] now with a flat bar that slides across to prevent sympathetic detonations. I hadn’t heard of it before, but found out it wasn’t that uncommon after it happened.”
Can you form a wildcat cartridge such as the 6 Dasher without expending primer, powders, and bullets? Absolutely. Using the hydro-forming method you can form improved cases in your workshop with no firing whatsoever, so there is no wear on your precious barrel. Watch this video to see how it’s done:
6 Dasher Case Hydro-Forming Demonstration:
Forum member Wes J. (aka P1ZombieKiller) has produced a helpful video showing how to form Dasher cases use the Hornady Hydraulic forming die kit. This includes a two-part die (body and piston), and a special shell holder. To form the case, you insert a primer in your virgin brass, top the case off with with a fluid (water or alcohol), then run the case up into the Hydro-forming die. A few stout whacks with a hammer and your case is 95% formed.
This same procedure can be accomplished with a Whidden Gunworks 6mm Dasher hydraulic form die. We like the Whidden hydro-forming die for its production quality and consistent results. This Whidden system works great according to our Forum members.
Hydro-Forming Procedure Step-by-Step:
1. Insert spent primer in new 6mmBR brass case.
2. Fill with water or alcohol (Wes prefers alcohol).
3. Wipe excess fluid off case.
4. Place case in special Hornady shell-holder (no primer hole).
5. Run case up into Hydraulic forming die.
6. Smack top piston of forming die 3-4 times with rubber mallet or dead-blow hammer.
7. Inspect case, re-fill and repeat if necessary.
8. Drain alcohol (or water) into container.
9. Remove primer (and save for re-use).
10. Blow-dry formed case. Inspect and measure formed case.
Wes achieves very uniform cartridge OALs with this method. He measured ten (10) hydro-formed 6 Dasher cases and got these results: two @ 1.536″; 2 @ 1.537″; and 6 @ 1.538″.
Three or Four Whacks Produces a 95%-Formed Case
With a Whidden or Hornady hydro-forming die, hydraulic pressure does the job of blowing out the shoulders of your improved case. The process is relatively simple. Place a spent primer in the bottom of a new piece of brass. Fill the case with water, and then slip it into a special Hornady shell-holder with no hole in the middle. Then you run the case up into the forming die. Now comes the fun part. You gently insert a plunger (hydraulic ram) from the top, and give it three or four stiff whacks with a mallet (or better yet, a dead-blow hammer). Remove the plunger and you have a 95% formed case, ready to load.
Special Shell-Holder
Hornady supplies a shell holder made specifically for the hydro die; there’s no hole in the bottom of it. Just insert a spent primer into the primer pocket and you’re ready to go. The spent primer, combined with the solid shell holder, keeps the water from seeping out of the primer pocket. The primer pushes out a little bit during this process, but it’s impossible for it to come out because of the way the shell holder is designed. The shell holder has a grove which allows the case to slide out of the shell holder even when the primer protrudes a bit.
The 6mm Creedmoor has become one of the most popular cartridges for PRS/NRL competition, and it also works great in the varmint fields. Good Lapua 6mm Creedmoor brass is available, and there are many 6mm Creedmoor factory rifle options now, such as the Savage Model 110 Elite Precision with MDT chassis and the Ruger Precision 6mm Creedmoor with 26″ barrel.
Do-It-Yourself 6mm Creedmoor Rifle Project — UltimateReloader.com
Another smart, cost-effective option for 6mm Creedmoor fans is to build your own rifle, starting with a Howa barreled action. The Howa 1500 is a mag-fed, flat-bottomed bolt action that ships with the excellent HACT 2-stage trigger. Howa 1500 full-size barreled actions have been available with a variety of barrel lengths and contours, starting at $429.99 at Brownells. Howa 1500 Mini barreled actions are available starting at $399.99 at Brownells.
There are quite a few good stocks/chassis systems now offered for Howa 1500 actions, including the excellent KRG Bravo Chassis, which features an ergonomic composite outer shell over a precision-machined inner chassis.
Gavin Gear fitted a KRG enclosed fore-end and Mystic Precision MPOD to his 6mm Creedmoor rifle.
Our friend Gavin Gear of UltimateReloader.com has built a nice 6mm Creedmoor rifle using a Howa 1500 heavy-barreled action and KRG Bravo Chassis. This project has proven very successful. The rifle has shown impressive accuracy and outstanding reliability. Gavin has used this rifle in some practical/tactical competitions, and it did well.
In this video, Gavin fits KRG’s enclosed fore-end to the KRG Bravo chassis. This accessory fore-end features a top Picatinny rail and various attachment options on the sides and lower section. Here you can see the enclosed fore-end (upper right) next to the factory forend included with the KRG Bravo (lower left):
Gavin then fits a Mystic Precision MPod from EGW. This stable, wide-base bipod uses a T-Slot rail for rifle attachment, and has legs that adjust independently for height. The video shows the rifle coming together step-by-step. This is something the average guy can do with simple tools — no gunsmithing is required, because the Howa barreled action is pre-chambered for the 6mm Creedmoor cartridge.
In the video above Gavin unboxes his Howa 1500 barreled action from Brownells. He then mounts the barreled action to the KRG Bravo stock, checking the torque levels. Next Gavin borescopes the hammer-forged barrel (5:55) noting: “What I saw I liked — there are practically no tooling marks. The finish on the lands and grooves looks really good”. Lastly, Gavin tested the trigger with his TriggerScan TS-11 (6:24), confirming a two-stage pull weight of about 2.25 pounds out of the box.
BONUS: PRB 6mm Creedmoor and 6.5 Creedmoor Load Survey
The Precision Rifle Blog (PRB) has compiled Load Data from PRS Competitors, for both 6mm Creedmoor and 6.5 Creedmoor. For new 6mm Creedmoor shooters, this PRB study 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.
Sierra Bullets has published load data for the 6mm Creedmoor cartridge. Sierra has released very comprehensive 6mm Creedmoor load data in printable PDF format, covering fifteen (15) different bullets from 55 to 110 grains. NOTE: Hornady brass was used for Sierra’s 6mm Creedmoor load tests, not the superior, stronger Lapua 6mm Creedmoor brass with small primer pockets. Hand-loaders using Lapua brass may have to adjust their loads.
Here are Sierra’s 6mm Creedmoor Load Data Charts for 90-95 grain bullets plus the 107gr MK. There are six more tables for other bullet types on Sierra’s 6mm Creedmoor Load Data Page.
Many shooters prefer to deprime their brass before resizing. That way they can tumble cases or keep primer debris off their main press. To deprime cases before sizing or cleaning you can use a Decapping Die. This pushes out the spent primer without changing the neck or body of a case. Such decapping dies work fine, but they do require the use of a press. Here is a handy alternative — a cool tool that allows you to deprime brass anywhere — no press needed.
Handheld Primer Removal Tool From Frankford Arsenal
This cleverly-designed Hand Deprimer Tool allows you to deprime cartridge cases without a press. This hand-tool from Frankford Arsenal will deprime brass and capture primers conveniently. You can deprime your cases while watching TV or relaxing in your favorite chair.
This device lets you remove spent primers anywhere — no press needed and all the mess (cups/anvils/residue) stays in the capture chamber. This tool comes works with nearly all common case types up to .338 Lapua Magnum. With good leverage, this tool does the job quickly and efficiently. Forum members have praised this handy tool, but recommend wearing a thick glove if doing more than 100 cases in a session.
This handy depriming tool is very versatile. With a universal, cylinder-style cartridge-holder, the tool can deprime a wide variety of cartridge types from .20 caliber up to .338 caliber. Three different plastic collets are provided to handle for different diameter cases. Spent primers are captured in a removable spent primer catch tube. Simply twist off the clear catch tube to dump the spent primers. With die-cast metal construction, this tool should last through many thousands of depriming cycles. MSRP is $54.99. Right now it is $47.98 on Amazon with 82% 5-star ratings.
User Modifications — Grip Padding and High-Volume Capture
Many users recommended putting some kind of padding on the grip and front lever to reduce pressure on the fingers. This can be done with a wrap or a rubber covering. In addition, users have adapted the unit with an attached hose and large primer capture jug. If you depriming hundreds of cases at a time, this hose conversion may make sense.
Review from actual owner: “I have owned one of these for about eight years and deprimed over 10,000 cases with this tool. I have never had to replace a single part on it. You will have to adjust the return spring every so often, but that is a very easy task. If you are depriming a LOT of brass, the handle can tear up your hand a bit. Solution: Wear a Mechanics Glove. Easy Peasy! You will NOT regret this purchase.”
How to Adapt Tool for Small Flash Hole Brass
The Frankford Arsenal Deprimer Tool was designed for LARGE flash-hole brass. To deprime brass with small (1.5mm/0.59″) small flash-holes, as found on Lapua .220 Russian and 6mmBR cases, you will need to reduce the pin diameter. Frankford Arsenal currently recommends purchasing a replacement pin and “sanding it down” to the smaller diameter. NOTE: This is NOT difficult — simply spin the stock pin in some sandpaper.
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.
The Summer Solstice is June 21, 2023, just a week away. And July is coming very soon. That means “peak heat” summer conditions. It’s vitally important to keep your ammo at “normal” temps during the hot summer months. Even if you use “temp-insensitive” powders, studies suggest that pressures can still rise dramatically when the entire cartridge gets hot, possibly because of primer heating.
It’s smart to keep your loaded ammo in an insulated storage unit, possibly with a Blue Ice Cool Pak if you expect it to get quite hot. Don’t leave your ammo in the car or truck — temps can exceed 140° in a vehicle parked in the sun.
To learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article Pressure Factors: How Temperature, Powder, and Primer Affect Pressure by Denton Bramwell. In that article, the author uses a pressure trace instrument to analyze how temperature affects ammo performance. Bramwell’s tests yielded some fascinating results.
For example, barrel temperature was a key factor: “Both barrel temperature and powder temperature are important variables, and they are not the same variable. If you fail to take barrel temperature into account while doing pressure testing, your test results will be very significantly affected. The effect of barrel temperature is around 204 PSI per F° for the Varget load. If you’re not controlling barrel temperature, you about as well might not bother controlling powder temperature, either. In the cases investigated, barrel temperature is a much stronger variable than powder temperature.”
This Editor had the personal experience of 6mmBR hand-loaded ammo that was allowed to sit in the hot sun for 45 minutes while steel targets were reset. The brass became quite warm to the touch, meaning the casings were well over 120° on the outside. When I then shot this ammo, the bullets impacted well high at 600 yards (compared to earlier in the day). Using a Magnetospeed, I then chron-tested the sun-heated ammo. The hot ammo’s velocity FPS had increased very significantly — all because I had left the ammo out in the hot sun uncovered for 3/4 of an hour.
LESSON: Keep your ammo cool! Keep loaded ammo in the shade, preferably under cover or in an insulated container. You can use a SEALED cool pack inside the container, but we do NOT recommend H20 ice packs. And don’t have the container do double duty for food and beverages.
Powder Heat Sensitivity Comparison Test
Our friend Cal Zant of the Precision Rifle Blog has published a fascinating comparison test of four powders: Hodgdon H4350, Hodgdon Varget, IMR 4451, and IMR 4166. The first two are Hodgdon Extreme powders, while the latter two are part of IMR’s Enduron line of propellants.
The testers measured the velocity of the powders over a wide temperature range, from 25° F to 140° F. Hodgdon H4350 proved to be the most temp stable of the four powders tested. [NOTE: New Alliant Reloder TS 15.5 has also proved very temp stable in AccurateShooter’s range tests.]
A while back, Sinclair International’s Reloading Press Blog featured a “round-table” discussion of reloading techniques. Sinclair’s team of tech staffers were asked: “What do you feel is the one-most crucial step in precision reloading?”
Report by Forum Member about Primer Flash-Over Incident
Hydro-Forming Procedure Step-by-Step:
Special Shell-Holder
To learn more about how ambient temperature (and primer choice) affect pressures (and hence velocities) you should read the article 
