Probably the most popular centerfire rifle round in the Western Hemisphere is the .223 Remington and its metric match, the 5.56x45mm. Though many folks use “.223 Rem” and “5.56×45″ interchangeably, there are some meaningful differences in specifications for the original .223 Rem and the 5.56x45mm cartridge, as adopted by the U.S. military and NATO armies. The default chamber throats are slightly different and the .223 Rem is rated at 55,000 PSI vs. 62,366 PSI for the 5.56x45mm.*
.223 Rem vs 5.56x45mm — Key Differences
There is a truly outstanding, very thorough article on the subject, published by LuckyGunner.com.** This involved extensive testing, with pressure monitors, of 5.56x45mm ammo in .223 Rem chambers. Those tests revealed the peak pressures. Here is one of the ammo test charts:
NOTE: “The observed chamber pressure for Federal XM855 5.56mm ammunition in a .223 Rem chamber exceeded .223 maximum pressures, but not by a massive amount. The ninth shot (the red line) was an underpowered cartridge which exhibited significantly lower velocity and pressure than the other rounds, so it was excluded from the average velocity and pressure numbers for this chamber.”
And if you’re curious, LuckyGunner also fired .223 Rem ammo in a 5.56x45mm NATO-chambered AR15 rifle. As you would expect, the peak pressures were significantly lower, but the .223 Rem ammo still cycled the semi-auto AR-platform rifle perfectly well:
UltimateReloader.com Explains .223 Rem vs. 5.56x45mm
To explain the key differences between the .223 Rem and 5.56x45mm cartridges our friend Gavin Gear of UltimateReloader.com has created a very thorough 12-minute video. This covers the cartridge specifications and explains key considerations for hand-loaders. Gavin also addresses the oft-asked question “Can I shoot 5.56x45mm ammo in my .223 Rem chamber?” Gavin’s video is definitely worth watching. In fact, this is one of the most popular videos Gavin has ever created — it has been watched nearly 4.5 million times on YouTube.
What Exactly Is the 5.56x45mm NATO Cartridge?
The 5.56×45mm NATO is a rimless bottle-necked intermediate cartridge family standardized by NATO with development work by FN Herstal. It consists of the SS109, SS110, and SS111 cartridges. Under STANAG 4172, it is a standard cartridge for NATO forces as well as many non-NATO countries.
Bullet diameter: 5.70 mm (0.224 in)
Maximum pressure (EPVAT): 430.00 MPa (62,366 psi)
Maximum pressure (SCATP 5.56): 380.00 MPa (55,114 psi)
Case length: 44.70 mm (1.760 in)
Rifling twist: 178 mm or 229 mm (1 in 7 in)
Parent case: .223 Remington (M193)
Ammo-Maker Federal Premium Compares .223 Rem and 5.56x45mm
Here is a video from ammo-maker Federal Premium explaining the difference between .223 Remington and 5.56x45mm NATO. Federal states that you may experience excessive pressures when firing a 5.56x45mm in a standard .223 Remington chamber:
One leading gunwriter has addressed the question of shooting 5.56x45mm ammo in .223 Rem chambers. He advocates caution (for more info, SEE pressure tests by LuckyGunner.com):
“I have received a slew of questions — many from first time AR-type rifle buyers — about the .223 Rem and the 5.56×45 mm NATO cartridges. Can I shoot 5.56×45 mm NATO in my .223 and vice-versa? Are these the same cartridge?
Externally, the two cartridge cases are identical. The main differences are that 5.56×45 mm NATO operates at a higher chamber pressure (about 60,000 PSI versus 55,000 PSI on the .223 Rem.) and the 5.56’s chamber is slightly larger than that of the .223 Rem. Also, the throat or leade is longer in the 5.56×45 mm chamber. What does this mean? You should not shoot 5.56×45 mm NATO out of a rifle that is chambered in .223 Rem [with a standard short throat]. And be aware that some .223 Rem ammunition will not reliably cycle through some AR-style .223 Rem rifles, but it usually does. As a matter of fact, I have not encountered any difficulty with current .223 Rem. loads cycling through a 5.56 mm AR-style rifle.” — Mark Keefe, Editor, American Rifleman
* According to the official NATO proofing guidelines, the 5.56×45mm NATO case can handle up to 430.0 MPa (62,366 psi) piezo service pressure. The U.S. SAAMI lists Maximum Average Pressure (MAP) for the .223 Remington cartridge as 55,000 psi (379.2 MPa) piezo pressure with deviation of up to 58,000 psi (399.9 MPa). The chamber for military 5.56×45mm NATO has a longer throat prior to the bullet contacting the rifling which results in lower pressures when firing 5.56×45mm NATO ammunition. If 5.56×45mm NATO is used in rifles chambered for .223 Remington the bullet will be engraving the rifling when chambered. which can increase pressures past SAAMI Max levels. NOTE: The C.I.P. standards for the C.I.P. civilian .223 Remington chamber are much closer to the military 5.56×45mm NATO chamber.
** The full-length LuckyGunner article is well worth reading. It even provides specifications for a number of .223 Rem reamer types, and compares the original .223 Rem, the 5.56x45mm NATO, and the modern .223 Wylde chamberings.
Put the same load in a variety of barrels (with the same length and chamberings) and you’ll see a wide variance in muzzle velocity. In fact, it’s not unusual to see up to 100 fps difference from one barrel to the next. We demonstrated this with a comparison test of Lapua factory ammo.
Chron Testing Lapua Factory Ammo
At our Southern California test range some years ago, we chronographed Lapua 105gr 6mmBR factory ammo in three different 8-twist barrels of similar length. The results were fascinating. Lapua specs this ammo at 2790 fps, based on Lapua’s testing with its own 26″ test barrel. We observed a speed variance of 67 fps based on tests with three aftermarket barrels.
Barrel Velocity Variance
Brand ‘S’ and Brand ‘PN’ were pre-fit barrels shot on Savage actions. Brand ‘K’ was fitted to a custom action. All test barrels were throated for the 100-108 grain bullets, though there may have been some slight variances in barrel freebore. With a COAL of 2.330″, the rounds were “jumping” to the rifling in all barrels.
Among the four barrels, Brand ‘PN’ was the fastest at 2824 fps average — 67 fps faster than the slowest barrel. Roughly 10 fps can be attributed to the slightly longer length (27″ vs. 26″), but otherwise this particular barrel was simply faster than the rest. (Click Here for results of 6mmBR Barrel Length Velocity Test).
IMPORTANT: Results Are Barrel-Specific, Not Brand-Specific
These tests demonstrate that the exact same load can perform very differently in different barrels. We aren’t publishing the barrel-makers’ names, because it would be wrong to assume that ‘Brand X’ is always going to be faster than ‘Brand Y’ based on test results from a single barrel. In fact, velocities can vary up to 100 fps with two identical-spec barrels from the SAME manufacturer. That’s right, you can have two 8-twist, 26″ barrels, with the same land-groove configuration and contour, from the same manufacturer, and one can be much faster than another.
Don’t Demand More Than Your Barrel Can Deliver
We often hear guys lament, “I don’t get it… how can you guys get 2900 fps with your 6BRs and I can only get 2840?” The answer may simply be that the barrel is slower than average. If you have a slow barrel, you can try using more powder, but there is a good chance it may never run as fast as an inherently fast barrel. You shouldn’t knock yourself out (and over-stress your brass) trying to duplicate the velocities someone else may be getting. You need to work within the limits of your barrel.
Factory Ammo Provides a Benchmark
If you have a .223 Rem, 6mmBR, .243 Win, 6.5×47 Lapua, 6.5 Creedmoor, 6.5×55, .308 Win, .30-06 Springfield, or .338 LM Rifle, we recommend you buy a box of Lapua factory-loaded ammo. This stuff will shoot great (typically around half-MOA), and it can give you a baseline to determine how your barrel stacks up speedwise. [Editor’s NOTE: The original test was conducted in 2008. The velocity of current-production Lapua factory ammo might be higher or lower, so your results may vary.]
When you complete a new 6mmBR rifle, it’s definitely smart to get a box of the factory ammo and chronograph it. That will immediately give you a good idea whether you have a slow, average, or fast barrel. Then you can set your velocity goals accordingly. For example, if the factory 6BR ammo runs about 2780-2790 fps in your gun, it has an average barrel. If it runs 2820+ in a 26″ barrel (or 2835 fps in a 28″), you’ve got a fast tube.
In years past, one of our favorite features on the NRA Blog was the Friday Feast Recipe of the Week. In the past, the NRA Blog offered up a new delicious food recipe each Friday. Sadly the Friday Feast has not been updated for quite some time, but you can still see dozens of past Friday Feast recipes with this link:
Today’s featured Friday Feast combines two things we love — Italian pasta and Elk meat. Article author Emily Rupertus shares our passion for pasta: “I love pasta. I can’t get enough of it! So when I came across this Classic Elk Lasagna, I couldn’t resist sharing with you! You have to try this perfect twist on a classic comfort food.” After assembling your Lasagna in a big cast-iron skillet and covering with tin-foil, bake the Elk Lasagna in a 400° oven for 30 minutes. Then remove the foil, add more cheese and continue to bake uncovered for ten more minutes.
Ingredients
1/2 Package of Lasagna Noodles
1 lb Ground Elk Meat (you can substitute ground venison or antelope)
1 Medium Sweet Onion (chopped)
2 Cloves Garlic (chopped)
2 tablespoons Olive Oil
3 Cups Tomato Sauce
32 oz. Ricotta Cheese
1 Cup Parmesan Cheese
1 8 oz. Fresh Mozzarella Cheese (sliced)
2 eggs
The CMP National matches at Camp Perry, Ohio kick off on July 6, 2025 and run through August 9, 2025. The National Matches are open to the public and have offered a wide range of events and matches since 1907. Held annually at Camp Perry, the National Matches include a wide range of events for rimfire rifles, centerfire rifles, and pistols. Listed below are event by category. Click on each discipline below for registration information, detailed match program, and schedule.
These matches are conducted by a partnership of the CMP and Ohio National Guard. Since their inception, the National Matches have become a huge national shooting sports festival with over 4,500 annual participants including many of the world’s best marksmen.
E-Targets at 2025 National Matches — Rimfire and Centerfire
After years of testing, the Civilian Marksmanship Program (CMP) will make full use of eTargets at the 2025 National Rifle Matches at Camp Perry, which run July 20 through August 9, 2025. The advanced Kongsberg eTargets will be used at all Highpower rifle matches, National Trophy Rifle competitions, and Rifle Games events. In addition the eTargets will be used for the Rimfire Sporter Match on July 20 and the National Mid/Long Range Matches in August. The use of eTargets eliminates the need for pit duty, drastically cutting down the duration of each match. “Shooting on eTargets is just a better experience for all competitors” notes Brian Williams, CMP Highpower manager. CLICK HERE to learn more about Camp Perry eTargets.
These matches are conducted by a partnership of the CMP and Ohio National Guard. Since their inception, the National Matches have become a huge, national shooting sports festival with well over 4,500 annual participants. School students and competitors range from beginners to many of the world’s best.
Feel free to contact the CMP Competitions Department at competitions@thecmp.org or (419) 635-2141, ext. 724 or 714 for additional questions.
The NRA Blog ran an feature on Silhouette shooting by NRA Silhouette Program Coordinator Jonathan Leighton. Here are selections from Leighton’s story:
NRA Silhouette Shooting
The loud crack from the bullet exiting the muzzle followed by an even louder ‘clang’ as you watch your target fly off the railing is really a true addiction for most Silhouette shooters. There is nothing better than shooting a game where you actually get to see your target react to the bullet. In my opinion, this is truly what makes this game so much fun.
Metallic Silhouette — A Mexican Import
Silhouette shooting came to this country from Mexico in the 1960s. It is speculated that sport had its origins in shooting contests between Pancho Villa’s men around 1914. After the Mexican Revolution the sport spread quickly throughout Mexico. ‘Siluetas Metalicas’ uses steel silhouettes shaped like game animals. Chickens up front followed by rows of pigs, turkeys, and furthest away, rams. Being that ‘Siluetas Metalicas’ was originally a Mexican sport, it is common to hear the targets referred to by their Spanish names Gallina (chicken), Javelina (pig), Guajalote (turkey) and Borrego (ram). Depending on the discipline one is shooting, these animals are set at different distances from the firing line, but always in the same order.
Before Steel There Was… Barbeque
In the very beginnings of the sport, live farm animals were used as targets, and afterwards, the shooters would have a barbeque with all the livestock and/or game that was shot during the match. The first Silhouette match that used steel targets instead of livestock was conducted in 1948 in Mexico City, Mexico by Don Gonzalo Aguilar. [Some matches hosted by wealthy Mexicans included high-ranking politicians and military leaders].
As the sport spread and gained popularity during the 1950s, shooters from the Southwestern USA started crossing the Mexican border to compete. Silhouette shooting came into the US in 1968 at the Tucson Rifle Club in Arizona. The rules have stayed pretty much the same since the sport has been shot in the US. NRA officially recognized Silhouette as a shooting discipline in 1972, and conducted its first NRA Silhouette Nationals in November of 1972.
Great Video of Silhouette Shooting in Canada with Drone Footage
Now There Are Multiple Disciplines
The actual sport of Silhouette is broken into several different disciplines. High Power Rifle, Smallbore Rifle, Cowboy Lever Action Rifle, Black Powder Cartridge Rifle, Air Rifle, Air Pistol, and Hunter’s Pistol are the basic disciplines. Cowboy Lever Action is broken into three sub-categories to include Smallbore Cowboy Rifle, Pistol Cartridge Cowboy Lever Action, and regular Cowboy Lever Action. Black Powder Cartridge Rifle also has a ‘Scope’ class, and Hunter’s Pistol is broken into four sub-categories. Some clubs also offer Military Rifle Silhouette comps.
Where to Shoot Silhouette
NRA-Sanctioned matches are found at gun clubs nation-wide. There are also many State, Regional, and National matches across the country as well. You can find match listings on the Shooting Sports USA website or contact the NRA Silhouette Department at (703) 267-1465. For more info, visit SteelChickens.com, the #1 website dedicated to Silhouette shooting sports.
Readers often ask “What’s the difference between a Weaver scope rail and a Picatinny Rail?” The answer is not as simple as it seems. The dimensions of a Picatinny Rail should be consistent (from one rail-maker to another), since there IS a government spec. Conversely, there is some variance in “Weaver-style” rails. The width of the groove is the most important difference between Picatinny Rails and Weaver-type rails. “Mil-spec” Picatinny rails will have a grove width of 0.206″ while Weaver rails typically have a narrower, 0.180″ groove width.
Does your rifle have a Weaver Rail or Picatinny Rail? Check the dimensions to be sure.
A while back, Brownells had a helpful GunTech™ Article that discussed the Picatinny Rail vs. Weaver Rail. That article explained:
What are the differences between the ‘Picatinny’ and the ‘Weaver’ systems? The profile of the two systems is virtually identical. Depending on the quality of the machining done by the manufacturer, the two systems should be indistinguishable from the profile. The key difference lies in the placement of the recoil grooves and with width of the grooves. MIL-STD-1913 (Picatinny) grooves are .206″ wide and have a center-to-center width of .394”. The placement of these grooves has to be consistent in order for it to be a true Picatinny MIL-STD system. Weaver systems have a .180” width of recoil groove and are not necessarily consistent in a center-to-center measurement from one groove to the next.
In many instances, a Weaver system has a specific application that it is machined for, so interchangeability is not necessarily an issue. A MIL-STD-1913 system must adhere to the specifications listed above in order for it to be considered MIL-STD, since the military desires uniformity in the recoil grooves to allow for different systems to be mounted on the weapon with no concern for compatibility.
Now, what does this mean? Boiled down, it means that accessories designed for a Weaver system will, in most cases, fit on a Picatinny system. The reverse, however, is probably not the case. Due to the larger recoil groove, Picatinny accessories will not fit a Weaver system. There are, of course, exceptions to every rule, but for a good rule-of-thumb, [full-width] Picatinny won’t fit Weaver, but Weaver accessories WILL fit Picatinny.
On Father’s Day, time spent together is more important than any gift that comes in a box…
Today is Father’s Day, a special Sunday when we acknowledge our patriarchs and show our gratitude for all their hard work and sacrifice on our behalf, and the love they have shown us over the years. If you’re lucky, you’re reading this after having spent a day at the shooting range (or the local fishing hole, or golf course) with your Dad. The important thing is to be together with “Pops” and do something you both enjoy together. If you haven’t finalized your Father’s Day planning, here are some suggestions:
1. Hand-wash and wax your father’s truck or car.
2. Clean your dad’s rifles, or help him put together some handloads.
3. Take your dad out to a live music concert, go to a ball game, or maybe head down to the local fishin’ hole.
4. Go for a hike together or just a drive in the country.
5. Head down to Sears or the local hardware store and let you Dad pick out some new tools.
6. Sit down with your dad, bring a note pad, and ask him to tell you some stories about his youth, or his military experience. This Editor learned some amazing things about his own father this way.*
Whatever you choose to do with your father, use your time wisely. Turn off your computer, and go be with your father today. Do something with him that makes him smile. The time spent together is more important than any gift that comes in a box. And, if he lives far from you, give him a call and let him know how important he is to your life. Remind him of the old adage: “Good fathers make good sons”.
When my father, a disabled WW2 Army vet, passed away I received the flag that was draped on his coffin. On most days I fly one of those nylon flags that you can pick up at hardware or department stores. But on holidays, like today, and his birthday, Dad’s flag is out there snapping in the breeze on top of the pole. I find myself talking to him as it gets put up in the morning and comes down at sunset. Hope when the time comes one of my boys will fly my flag. — Bill Slattery Jr.
My father used to play with my brother and me in the yard. Mother would come out and say, “You’re tearing up the grass”! “We’re not raising grass,” Dad would reply, “We’re raising boys”. — Harmon Killebrew.
* My father was a Lieutenant in the U.S. Army in WWII. He was part of three different amphibious landings — North Africa, Sicily, and Operation Dragoon in the South of France. During one conversation about the French invasion, he showed me the invasion armband he wore in 1944. He had kept that band, with its faded American flag, for over 50 years. It is now a cherished memento of his life and service to his country.
Emil Praslick III is widely recognized as one of the greatest wind wizards on the planet — a master at identifying wind value and direction, and predicting wind cycles. As coach of the USAMU and top civilian teams, Emil has helped win many high-level championships. In the three videos we feature today, Emil, who works with Capstone Precision Group (Berger, Lapua, SK, Vihtavuori) and Team Applied Ballistics, explains how to determine wind direction and velocity using a variety of indicators. Praslick, now retired from the U.S. Army, was an 18-time National and 2-time World Champion coach with the USAMU.
Video ONE: Wind Theory Basics — Understanding “Wind Values”
In this video from UltimateReloader.com, Emil explains the basics of modern wind theory. To properly understand the effect of the wind you need to know both the velocity of the wind and its angle. The combination of those variables translates to the wind value. Emil also explains that the wind value may not be constant — it can cycle both in speed and velocity. Emil also explains some of the environmental conditions such as mirage that can reveal wind conditions.
Video TWO: Determining the Direction of the Wind
Key Point in Video — Find the Boil
Emil explains how to determine wind direction using optic. The method is to use spotting scope, riflescope, or binoculars to look for the “Boil” — the condition in mirage when the light waves rising straight up. The wind will generate that straight-up, vertical boil in your optics when it is blowing directly at you, or directly from your rear. To identify this, traverse your scope or optics until you see the boil running straight up. When you see that vertical boil, the direction your optic is pointing is aligned with the wind flow (either blowing towards you or from directly behind you).
Video THREE: The No Wind Zero Setting
In this second video, Emil defines the “No-Wind Zero”, and explains why competitive shooters must understand the no-wind zero and have their sights or optics set for a no-wind zero starting point before heading to a match. In order to hit your target, after determining wind speed and direction, says Emil, “you have to have your scope setting dialed to ‘no wind zero’ first.”
Coach of Champions — Emil Praslick III
SFC Emil Praslick III, (U.S. Army, retired) works with Berger Bullets and Applied Ballistics. Emil served as the Head Coach of the U.S. National Long Range Rifle Team and Head Coach of the USAMU for several years. Teams coached by Emil have won 33 Inter-Service Rifle Championships. On top of that, teams he coached set 18 National records and 2 World Records. Overall, in the role of coach, Praslick can be credited with the most team wins of any coach in U.S. Military history.
Want to learn the basics of position shooting? Then you should check out an article by Gary Anderson, DCM Emeritus, in On the Mark digital magazine (Summer 2014, pp. 6-13). This article covers all the key elements: body position (prone, sitting, standing), sling use/adjustment, sight picture, aiming process, and trigger control. While this 8-page article was specifically written for Rimfire Sporter shooters, the techniques described by Anderson apply to all types of position shooting, whether you shoot air rifles, smallbore rifles, or centerfire rifles.
Here’s what Anderson says about aiming — how to keep your sights steady and get them centered on the middle of the target:
Trigger Contact and Center As soon as aiming at the target begins, the index finger must move from the trigger-guard to contact the trigger. It is important to get initial pressure on the trigger as soon as aiming begins. Then the shooter must focus on the sight picture and centering the sight picture movements over the aiming point. No one, not even champion shooters, can hold the aligned sights perfectly still. The sights are going to move a little bit or a lot, depending on the shooter’s skill level. The secret is to center those sight picture movements over the aiming point on the target (see trace illustration) before pulling the trigger.
When the sight picture movements on the target are centered, the last step in firing the shot is to add… smooth pressure on the trigger until the shot breaks.
Anderson also discusses the 5 Basics of Shot Technique:
BONUS: Olympic Gold Medalist Jamie Gray
Here’s an interesting video about three-position shooting. Produced by GOnra Media, this video demonstrates rifle hold and body alignment for prone, standing, sitting, and kneeling positions. Olympic Gold Medalist Jamie Gray demonstrates the proper stance and position of arms and legs for each of the positions. Ideally, in all of the shooting positions, the shooter takes advantage of skeletal support. The shooter should align the bones of his/her arms and legs to provide a solid foundation. A shooter’s legs and arms form vertical planes helping the body remain stable in the shooting position.
This USAMU article explores three different “Philosophies” of precision reloading. Some handloaders seek to produce ammo that yields the very tightest groups (without factoring in the wind). Other shooters load their ammo to deliver the highest safe velocity. That’s because a projectile launched at higher velocity will drift less in the wind. The theory is that even if fast ammo doesn’t produce the tightest groups in zero wind conditions, it will yield higher scores in a the real world (where the wind blows). Lastly, some handloaders favor ammo that is ultra-consistent across a wide temperature range. This last philosophy dictates selection of a powder that is temp-insensitive, even if it may not produce the very best raw accuracy (or speed).
What’s Your Handloading Philosophy?
Objectives of Reloading — Accuracy, Velocity, Temp Stability What do you, the reader, primarily value in your handloads?
Viewpoint ONE: Accuracy Trumps Everything
Some shooters prize consistent, excellent medium/long range accuracy enough that they’re willing to give up some extra velocity (and reduced wind deflection) to obtain that. Their underlying philosophy could be stated: “Superior accuracy is present for every shot, but the wind isn’t”. One’s ability to hold well, aim well and read the wind are all factors in making this type decision. The photo below shows stellar raw accuracy. This is an 0.67″, 10-shot group at 300-yards fired from a text fixture. The group measures just 0.67″. (This shows the USAMU’s 600-yard load with 75gr bullets).
Viewpoint TWO: Load to Highest Safe Velocity for Less Wind Drift
Some shooters value obtaining the highest safe velocity, even if one’s pure, consistent mechanical accuracy at medium/long range isn’t quite as brilliant. The theory here seems to be that a really good hold extracts as much mechanical accuracy from the rifle/ammo as possible, and faster bullets equal occasional “bonus” points snatched from the jaws of wind.
[For example] one of the USAMU’s many Service Rifle National Champions revealed his philosophy. It can be stated thus: a super-accurate, but [relatively] “slow” load “required him to have a Ph.D. in wind reading for every shot, while a faster, but less accurate load netted him more points.”
Note — this was not mere speculation; his score book data backed up his claims, due to less wind effects. Remember, however, this fellow has a consistent, National Championship-level hold, and other Champions on the same team would have opted differently.
Viewpoint THREE: Temperature Stability Is Key
Still another approach is to place heavy emphasis on fine accuracy with absolute stability in changing temperatures. When this writer was actively earning his Distinguished Rifleman badge, that was his goal. The reason? Sighting shots are not allowed in EIC (“Leg”) matches. The first shot out of the barrel was for score. It had to be 100% consistent, with very reliable, predictable elevation and wind deflection regardless of the ambient temperature — even if it wasn’t the lowest wind deflection possible.
Naturally, selecting a powder that is insensitive to temperature changes is a key element here. Elevation zeros and wind effects HAD to be consistent every time. Hunters and military snipers might be among those who fall into this camp, as well as those in pursuit of their Distinguished Rifleman badges.
Contrast that with a traditional High Power shooter who gets two sighter shots before each event (offhand, sitting rapid, prone rapid, prone slow fire.) If there is a zero change on any given day, he/she can correct during sighters. This writer well remembers talking with another very high-level Service Rifle competitor who was happy to have high temperatures boost the velocities of his ammunition above their usual level… As far as this SR competitor was concerned, 60-80 fps more velocity -– even if only due to high ambient temperatures -– meant less wind deflection, and he was mighty happy to have it.
Particularly in the summer, with hot daily conditions, you need to be concerned about temperature stability. Loads worked up in winter may not work in the summer time.
This article has been confined to NRA High Power Rifle competition, which has relatively generous 10-ring dimensions in relation to the accuracy of well-built competition rifles. Hopefully, it will provide food for thought. For some, this might be an opportunity to ensure that one’s load development approach helps them attain their desired results.
Barrel Velocity Variance
The 
Metallic Silhouette — A Mexican Import
Before Steel There Was… Barbeque
Today is Father’s Day, a special Sunday when we acknowledge our patriarchs and show our gratitude for all their hard work and sacrifice on our behalf, and the love they have shown us over the years. If you’re lucky, you’re reading this after having spent a day at the shooting range (or the local fishing hole, or golf course) with your Dad. The important thing is to be together with “Pops” and do something you both enjoy together. If you haven’t finalized your Father’s Day planning, here are some suggestions:
As soon as aiming at the target begins, the index finger must move from the trigger-guard to contact the trigger. It is important to get initial pressure on the trigger as soon as aiming begins. Then the shooter must focus on the sight picture and centering the sight picture movements over the aiming point. No one, not even champion shooters, can hold the aligned sights perfectly still. The sights are going to move a little bit or a lot, depending on the shooter’s skill level. The secret is to center those sight picture movements over the aiming point on the target (see trace illustration) before pulling the trigger.
