April 2011 Cover Page

  April 1940
  
The Rifleman's Journal
A Collection of Articles Dealing with Rifle Accuracy Topics


This Month:
Hap Rocketto - Hap's Corner
Germán Salazar - .308 vs .30-06 Comparison
Harry Pope - Directions For the Pope Muzzle-Loading System


15 Cents 

Reloading: Palma Questions and Tips

This month's question comes from Dave in Ohio.

Reloading: Palma Questions and Tips
by Germán A. Salazar



Good Afternoon Germán!

Just thought I would drop you a line and again thank you for your pointers and the always informative articles on The Rifleman's Journal website.

With the info I have been able to glean from your writings I have the new Palma rifle working waaayyyy better that I can. If you might recall I took a trip to Colorado last Labor Day to visit family and while there planned on shooting at Byers for a two day Fullbore style match. I learned a lot in the wind and things went well until the 1000 yards leg of the match. After your article about the 175 grain bullets for Palma and the need for our handloads to have the bullet stay above 1.2 mach, I deduced that the ammo I had loaded and tried out to 600 yards was probably going transonic somewhere between 900 and 1000 yards. So after some surfing on the internet and a couple of visits to JBM Ballistics, I tried several combinations of 180 grain weight range bullets and obtained a sample of JLK 180 grain LBT bullets.

This spring the club I belong to (Alliance Rifle Club) opened its new 1000 yard range along with firing points for 800 and 900 yards (did I tell you how badly I've been bitten by the Palma bug?). Well testing with both 180 SMK's out to 900 and the JLK bullets at 800, 900 and 1000 fired out of the Obermeyer barrel (1:12" twist) has been most satisfying! I guess the only questions I have is with a load that boringly holds waterline on the X and 10 ring are:

1 - With an extreme spread average for 20 shots of 24 fps should I try to lower that number? and,

2 - What tricks might you suggest to get the ES lower if needed.

I am using Winchester brass, two stage sized (body die then neck die), 0.003" neck tension, Wolf LR primers (another great article), IMR 4895 powder and the barrel is chambered with the latest PTG 2011 Fullbore reamer with a 0.344" neck and with fired cases measuring 0.343" to 0.3435". All cases trimmed to 2.010" and the flash holes deburred but primer pockets not uniformed.

Please understand that I don't think that this load is broken so I am not sure I want to fix it. Just looking for your valued thoughts on the topic.

Dave


Dave,

It's good to hear from you again, and I'm glad the various articles have been helpful in developing your loads for Palma shooting. As you've discovered, the 1000 yard stage of the Palma is where the load often falls apart because not every bullet can successfully be kept above 1.2 mach at that distance (with safe pressure levels). Your choice of a high BC 175 grain bullet (the JLK) is a  great one and will keep your loads working well. The Sierra 180 works fine through 900 yards, and, in fact is the very same thing I plan to shoot next season to save my limited number of 175 Bergers for the 1000 yard line.

You mentioned that you have an extreme spread (ES) of muzzle velocity of 24 fps for a 20 shot string. Certainly the amount of variance in muzzle velocity in a long-range load is important, but I believe that the standard deviation (SD) of a load is a far better measure of a load's variance than is the ES. Simply stated, ES is a measure of only two shots whereas SD is a measure of every shot fired. The more shots you fire, the likelier ES is to grow (it will never shrink) but that's not necessarily telling you what you need to know. SD might grow or shrink with an increasing number of shots and gives you a very accurate measure of what you can expect the next shot to be. Our earlier article Statistics for Rifle Shooters by Jerry Engleman provides a good analysis of this.

To simplify a bit, let's look at a hypothetical string of shots over a chronograph:

2950, 2975, 2952, 2956, 2952, 2949, 2959, 2957, 2962, 2956, 2956, 2955, 2950, 2960, 2954, 2962, 2958, 2957, 2956, 2959

There we are.  What's the ES? A quick scan shows us that the low MV is 2949 and the high is 2975, so the ES is 26 fps. If you really look at that, the 2975 is quite a bit higher than the next highest MV (2962), was it a fluke? Was it the outlier on the bell curve that would result from testing 1000 rounds? Should it influence us? Should we ignore it and recalculate?

Most of those questions can be answered through good statistical methods, but there is another way to look at it - what is the SD? for that we need to do a bit of calculation. Here's a handy webpage for this purpose: http://www.easycalculation.com/statistics/standard-deviation.php .

We find that the SD of this string of shots is 5.7, which is perfectly acceptable for LR shooting. In reality, these numbers are made up and usually SD is pretty close to 1/3 of ES for a well developed load, but this is just an example.

Now let's look at another example:

2950, 2965, 2952, 2966, 2952, 2969, 2959, 2967, 2952, 2966, 2956, 2965, 2950, 2960, 2954, 2962, 2958, 2967, 2956, 2969

The ES of this sample string is 19 fps, a bit lower than the first one, but the SD is 6.7 - still quite good but higher. How did the SD increase when the ES decreased? Simple, we eliminated the one high shot, but introduced more shot to shot variance. This shows you how SD takes all shots into account and how low shot to shot variance, which keeps you from chasing elevation shots all day is the better approach.

Although the numbers are made up, they are a reasonable representation of Palma loads.

A single stray MV can come up at any time, it shouldn't be the one shot that defines the load's level of variance - SD will use every shot fired to grade variance and gives you a fuller picture of what you can expect from that load. An SD of 12 or under is quite good and anything in the single-digit range. is very good. However, that doesn't guarantee accuracy - you'll still need to test the load at 1000 yards to be sure of that. However, a load with a high SD is unlikely to ever be accurate at 1000 yards.

Now, let's look at your other question - how to reduce variance in MV.

A great deal of what I've written in past articles deals with this very subject. Reducing the variability of the elements and techniques that make up the cartridge will reduce MV variance.

Careful selection of primers, and proper primer seating is a tedious but rewarding area of effort. Look for a primer that produces a low MV with a basic load, then work the load for accuracy using that primer. There are many primer articles on this site (they even have their own index section), read them all and give them careful thought.

Case necks are the most important part of the case. Very consistent neck tension is critical to a low SD. I turn all my case necks and size for 0.0015" to 0.002" neck tension, this seems to work very well in my Palma loads.

Seating depth of the bullet is another area that can affect accuracy generally and SD specifically. All I can say here is don't overlook seating depth when thinking of MV variance.

Finally, bullets themselves can have a large effect on MV variance. The biggest thing to look for is consistent length of bearing surface. I think life is too short to be measuring and sorting bullets, so for 1000 yards, I use bullets that I know (from previous testing) to be consistent. If I were to have a sudden drop off in performance with a new lot of bullets, I'd start checking that lot, but so far, with the 175 Berger BT, I haven't had that problem.

Details, details, details... that's the key to low variance in your long-range .308 loads.

Equipment: Canadian F-Class Bipod

Made in Canada: Henry Rempel's F-Class Bipod
by Germán A. Salazar


I've been promising my F-Class friends for some time that I'll shoot a few F-Class matches with them; however, finding the motivation to ditch the sling has always been difficult. Now, with my right (sling) shoulder still healing from rotator cuff surgery, I'm taking the first steps toward fulfilling my promise.  Obviously, it will be quite some time before I can get in the sling again, but hopefully I'll be able to shoot F-Class in a few months. In anticipation of that, I ordered an F-Class bipod from Henry Rempel in Alberta.

Henry has been making his bipod for a while, and although he ships them all over the world, he tells me that not too many seem to come south of the border to the U.S. Some of that is likely due to the weight of the bipod; at 3 lb. 5 oz. it's heavier than the Sinclair and many U.S. shooters with purpose-built F-TR rifles want to keep the bipod as light as possible to allow for maximum barrel weight. In other countries, by contrast, a higher percentage of F-TR rifles are former TR (Palma) rifles and have no trouble staying under the ICFRA weight limit of 8.25 kg (18 lb. 2 oz.) with scope and bipod.

One look at the Rempel bipod was enough to convince me that it was the one for me. The sheer mechanical beauty of the design as well as Henry's obvious machining skill came shining right through the pictures he sent and I placed my order straight away. I had some concerns about the international order: how would I pay for it, how long would it take, how would it fare in transport, that sort of thing. I needn't have worried. Henry answered all my questions promptly via email, payment was through PayPal and they handle the currency conversion and shipment through Post Canada took six days. Henry sent me an email with the tracking number of April 7th and the package arrived promptly on April 13th.

Speaking of the package, other retailers of shooting goods could take a lesson from Henry! A sturdy wood and corrugated plastic container custom made for the bipod ensured that no harm occurred during shipment. Inside, the bipod was nicely braced and padded to keep it from moving about. Properly labeled and insured, the packaging truly evidences the professional operation behind this product.

Most bipods attach to the rifle by way of a sling swivel stud; although it is a functional method of attachment, there is some room for improvement. The Rempel bipod, by contrast, attached to the rifle through a cam lock attachment into a socket plate that fits into the accessory rail. The socket plate has two attachment pieces that function the same as the one on a handstop. The bipod then clamps onto the socket plate with a very robust cam lock. This is as solid as the lock-up of the rifle bolt's locking lugs closing as you rotate the bolt.

The long handle actuates the cam lock into the socket plate (shown already on the bipod).
Once you have the bipod attached to the rifle, you'll want to adjust the height and the cant of the rifle to suit the firing point and match up to your rear bag. To adjust the cant, loosen the large central lever and rotate the rifle to the desired degree of cant. To adjust the height, loosen the two smaller knobs and use the stainless steel mariner's wheel at the bottom to adjust; as you raise the height, the legs come closer together. The feel of the unit as you make the adjustments is one of bank vault solidity - very impressive.

The Rempel bipod's feet have been described as being similar to a ski plane's runners. I'm no aviation expert, but they certainly appear suitable for their intended use on grass, dirt or concrete. The runners look like they will slide freely on any of those surfaces. Take a close look at the quality of design and machining on all of the parts shown, this is just beautiful work.

With the locking knobs facing the shooter, adjustments can be made quickly during a match.

All four legs are milled out from the underside to save weight. .












Another view of the bipod attached to the rifle.

















Contact Henry Rempel at henry.rempel@hotmail.com for more information. As of this writing, the price is C$400 plus C$40 shipping and C$13 PayPal fee for a total of C$453. The conversion to US dollars made it US$479.95.

A Note To My Friends

I had surgery on Friday 4/8/11 to repair significant rotator cuff damage in my right shoulder.  My ability to respond to email is very limited. I'll get the site updated slowly.

Germán

History: Images From The War Years

Images From the War Years
by Germán A. Salazar
Opened in 1816, Philadelphia's Frankford Arsenal during World War II was one of the Army's four master depots, which stocked material for quick delivery to troops and the Army's forward depots. It also developed and manufactured small arms ammunition, and a range of instruments and gauges. During the war the Arsenal employed more than 20,000, including many women. The Arsenal finally closed for government use in 1977.

Of course, the Frankford Arsenal was just one of thousands of industrial facilities converted to military production for the duration of the war. Here we bring you photos from a few of them, with a special emphasis on the work done by women to keep the Allied war effort well supplied.


Women firing .50 caliber machine guns at Frankford Arsenal



Miss Elizabeth Kochersperger conducting test to determine the mechanical properties of the metals to be used for Ordnance material at Frankford Arsenal

Mrs. Doris Cashmer and Mrs. Lucille Owens prepare high-speed X-ray apparatus for photographing a bullet in motion in a gun barrel at the Frankford Arsenal Laboratory, Philadelphia, PA, circa 1944.


MOTHER OF THE ASSEMBLY LINE - Clip spring and body assembly for .30 caliber cartridges at the Frankford Arsenal, Philadelphia. 


Inspection of permanent mold castings following treatment is made by some of America's women war workers. 


Loading anti-aircraft cases into a stress-annealing furnace to make them soft, uniform, and ductile - ready for succeeding machine operations. 

With the grace and dexterity of a master dressmaker, this attractive young woman fabricates "pup" tents for the expanding war army at the Langdon Tent & Awning Company. 

Vital tin and alloy metals are conserved by this procedure.


Conservation of waste paper will save millions annually for Uncle Sam.

The hand that rocks the cradle can also rock the Axis. American women are rapidly taking their places on the industrial front. Here in this small factory, the owner's wife operates one of the machines making dies for incendiary bombs. 

English women members of the Auxiliary Territorial Service move armfuls of American rifles just arrived from US under lend-lease. 

Water-cooled machine guns just arrived from the USA under lend-lease are checked at an ordnance depot in England. 
Cases of American spare parts arriving at an English ordnance center as part of lend-lease shipment from the USA. English women, driving trucks, help with the task. 

Although her mind is far from vengeance to be wreaked on the Axis powers, this little lady is contributing to their defeat. She has gathered up an old bicycle tire and other odds and ends to contribute to the scrap rubber collection drive. 

Answering the nation's need for womanpower, Mrs. Virginia Davis made arrangements for the care of her two children during the day and joined her husband at work in the Naval Air Base in Corpus Christi, Texas. 

Pearl Harbor widows have gone into war to carry on the fight with a personal vengeance. Mrs. Virginia Young (right), whose husband was one of the first casualties of World War II, is a supervisor in the Assembly and Repairs Department of the Naval Air Base at Corpus Christi, Texas. Her job is to find convenient and comfortable living quarters for women workers from out of the state, like Ethel Mann, who operates an electric drill. 

With a woman's determination, Lorena Craig takes over a man-size job. Before she came to work at the Naval Air Base in Corpus Christi, Texas, Lorena was a department store girl. Now she is a cowler under Civil Service. 

Grace Janota, former department store clerk, is now a lathe operator at a Western aircraft plant producing B-24 bombers and C-87 transports. 

Part of the cowling for one of the engines for a B-25 bomber is assembled in the engine department of North American's Inglewood, California plant. 

A landing gear, ready for assembly on a B-25 bomber, is rolled into place on the final assembly line of North American's Inglewood, California plant. 

History: Directions For Handling Pope Muzzle-Loading Rifles

Regular readers and students of shooting history should need no introduction to Harry Pope, the greatest barrel maker who ever lived. Here is a short item by Pope which I recently found as an appendix to the book Sporting Rifles and Rifle Shooting by John Caswell (D. Appleton & Co., New York,1920). The Pope muzzle-loading system used a false muzzle to start the bullet into the barrel and a cartridge case holding the powder was loaded from the breech. This system dominated Schuetzen shooting from its inception. Anyone fortunate enough to have a Pope rifle today might appreciate hearing these directions in the words of the Master himself. The rest of us can use it to fuel our imagination. - GAS -

Directions For Handling Pope Muzzle Loading Rifles
by Harry M. Pope

Harry Pope 1941
 Tie your false muzzle to the loading rack. This prevents your shooting it off and also prevents the gun from falling, as it is to be kept on the gun until ready to shoot.

Seat your bullet as soon as possible after firing so the powder dirt will not have time to harden and make it load hard. To seat the bullet stand the gun in the rack so the barrel will be vertical, breech open. Wipe off the muzzle with a bit of waste carefully with the blinder pin in line of sights; push it down gently; keep the muzzle pins clean and occasionally smear them with a bit of bullet grease. Place a bullet on the muzzle with the left hand, with the starter in the right hand, plunger down, place cup of plunger on point of bullet and slide the starter down onto the false muzzle; hold the starter down tight onto the false muzzle with the left hand and drive the bullet in the length of the starter plunger with ONE BLOW with the ball of the right hand. Strike in line of plunger and do not strike with the palm as it will hurt and make your hand sore. Do not strike several blows as the bullet upsets each time and goes with difficulty. Get the knack of the exact strength required and strike but once. Pull up the plunger with the right hand while still holding the body down with the left so the plunger will not rub in the rifling and wear it. When the plunger is way up hold it there with your thumb and remove the starter from the muzzle, still holding the false muzzle to the barrel; with the knob. Take your ramrod and hold it short with both hands and push hard and straight to start the bullet part way down. Don't drive it—push, then shift your grip to the knob and push it gently clear down to the knob.

Now—LISTEN—Leave your gun in the rack this way, muzzle tied to the rack, muzzle on barrel, rod way down, till you are ready to shoot. The fact that it is so shows you have seated a bullet to place and no injury can come to the barrel. Load shell and then remove the rod slowly to prevent suction; go to the firing point and look into the breech to see the bullet before you insert the shell to shoot.



Cautions

Always see that the rod is in the barrel as described before you shoot. That is a sure preventive of having a bullet seated and another started or of having the bullet only part way down.

If your shell should apparently miss fire, look into the barrel. If the bullet is still in it, go back to the stand and put on your muzzle and put your rod down to place. Sometimes one puts on a primer only which drives the bullet up the barrel and if the bullet was not returned to place the next shot would bulge the barrel.


Don't lose your false muzzle, it cannot be duplicated.



Don't carry the false muzzle on your gun. If it should fall it is liable to injure both it and the barrel. Carry the ramrod in the barrel, then if it falls the wooden knob makes a cushion that prevents injury to the end of the barrel.

One way of injuring a barrel is to shoot a bullet part way down. This usually makes a powder ring. To shoot a bullet from the breech against one only started down ruins the barrel except for rebore to a larger size. Exploding a primer only and driving the bullet part way out to be ringed by the next powder charge, unless pushed back into place. Leaving the rod in place as above prevents all but the last of these.

NEVER insert the loaded shell till at the firing point.

Loads 2 1/2 Peters primer, 5 grains weight FFG Semi Smokeless, 19 or 20 grains weight, of Du Pont's Schuetzen smokeless. This leaves the shell nearly full—postal card wad—bullet 1 part tin to 27 parts lead. This is a very accurate load with light recoil. I use it.

Another—Either 2 1/2 Peters or No. 8 U.M.C. primer, 3 grains weight of Schuetzen Smokeless or Du Pont's No. 1 Smokeless rifle; shell nearly filled with FG or FFG Semi Smokeless. Bullet 1 tin to 30 lead—postal card wad.

When through shooting, load a bullet as usual, but push it clear through with the cleaning rod. Wipe thoroughly and dry and grease with Pope's "Leadoff" which is a splendid rust preventer and also a very quick lead remover.





Related Articles

The Old Master: The Story of Harry Pope

The Secret of the Old Master

Pope Rifle Barrels
Another article about Harry Pope can be read via this link, it is from the March 1920 issue of Popular Science magazine.

Cartridges: Sibling Rivalry: .308 vs. .30-06

Sibling Rivalry: .308 vs. .30-06
by Germán A. Salazar

For much more .30-06 and .308 information, click the Article Index tab above.


Frankford Arsenal .30-06 Match - Lake City .308 Match


Middleton Tompkins 1958
Introduction
In 1956, eighteen year-old Middleton Tompkins won the NRA Junior Highpower Championship with his .30-06 Winchester Model 70. Two years later in 1958, by then out of the Junior ranks, he won the overall championship. At that time .30 caliber shooting, as Highpower was commonly known, was strictly a .30-06 proposition. However, the .308 was on the horizon and shooters were aware of its potential. After a few years away from the winner's podium and looking for an edge, Mid put together one of the first .308 bolt-action match rifles and used it to win the 1963 NRA Highpower Championship, the second of his six overall victories (1958, 1963, 1964, 1967, 1968, 1982); it was the first ever win for anything other than the .30-06 in the Highpower championship.


Middleton Tompkins 1963 Highpower Bolt Gun Champion
with Service Rifle Champion Kruk.

I recently asked Mid about his decision to try the .308 in 1963. He said: "At that time I was doing a lot of testing for the Air Force on the AR15 and we shot the M14 a great deal to compare them. That made me think the .308 would be a useful cartridge for Highpower bolt-gun shooting. The rule book said the cartridge had to be .30 caliber, but it didn't say it had to be a .30-06. We built a .308 Model 70 and in all our testing, it outshot the .30-06, so I took it to Camp Perry. I'm pretty sure it was the first one there." Mid described making a clip slot for the rifle from a piece of aluminum using only a few files. He needed the extended, bolt-on, clip slot rather than the one cut into the action in order to position the shorter .308 cartridge at the front of the magazine box. Roy Dunlap saw it at Camp Perry and began making them commercially. Mid said "Roy made the best clip slots for the .308 conversion."

That long-ago summer day at Camp Perry changed NRA Highpower shooting forever; over fifty years of unchallenged .30-06 domination quickly came to an end. Eventually, in the mid 1980's, the NRA would drop the .30 caliber requirement altogether for across-the-course shooting, opening the door to the sub-caliber gamesmanship approach to Highpower. Those who adopted that view shifted from the .308 to the 7mm, 6.5 mm and 6 mm cartridges and began to dominate the top of the results sheets. The final slap in the face to us .30-06 shooters came a few years later when the NRA dropped the .30-06 as an eligible cartridge for Palma shooting. I shoot with Mid frequently and often jokingly remind him that the whole sub-caliber craze is his fault!

The Eternal Debate
Notwithstanding the .30 caliber cartridges' fade-out from NRA across the course shooting, for the past five decades, shooters have argued over the relative merits of the .308 versus the .30-06. That argument isn't likely to be settled in our lifetimes. That's a good thing, after all we need something to talk about after were done shooting and I've certainly been involved in many of those discussions - I might have even instigated a few... It isn't quite the Civil War, pitting brother against brother, but more than a little heat has been generated by some of those friendly debates. The problem with those arguments, however, especially those on the internet, is the lack of a common set of standards - sometimes it seems as though we're all talking past each other.

Middleton Tompkins and German Salazar - April 1, 2011
It's impossible to have a universal basis for comparison when some fellows who are recreational benchrest type shooters and want to measure a few groups at 100 yards, others like to shoot a bit further to let these cartridges stretch their legs. A few want to compare available factory match ammo. Then there are the hunters who want to talk about terminal ballistics and the military buffs who want to know which cartridge legendary Marine sniper Carlos Hathcock used in Vietnam (both) or what snipers use today. Apart from differing standards of comparison, most people want to base their analysis on far too little data. They want their single highest score or best group to represent their favorite cartridge's capability - that's simply not realistic, nor statistically sound.

The one group of shooters we don't hear from too much in these discussions is Highpower shooters and the reason is simple: both cartridges are now essentially obsolete for NRA across-the-course Highpower shooting. In prone matches we see a bit more use of the .30 caliber. The .308 is required for Palma shooting, so it is also used by many Palma competitors in other long-range and mid-range prone matches. However, the .30-06 is well and truly dead except for a handful of hard-core .30 caliber shooters - a proudly stubborn group among which I count myself.

I'm not a benchrest shooter, nor am I a hunter, nor do I shoot factory ammunition, nor do I participate in any form of competitive shooting other than NRA Highpower prone - I just don't have the time. However, when it comes to NRA Highpower prone, whether mid-range or long-range, I think I can offer some useful thoughts to those who are interested in learning more about how these two cartridges compare. Accordingly, our cartridge comparison will use scores fired in NRA prone Highpower matches as the basis for our accuracy comparison. Apart from the fact that I have a good database of scores to use for this purpose, I believe that scores offer a more meaningful measure of accuracy than group sizes; after all, a score counts every shot, whereas a group accounts only for the two worst shots. This is perfectly analogous to the difference between extreme spread and standard deviation when measuring muzzle velocity.

All scores were fired in competition, with iron sights, from a sling supported prone position. Each cartridge was fired with two well built rifles over a period of 27 months of cold, hot, windy, calm and sometimes dangerous weather. The total number of rounds analyzed was 4,800 rounds at mid-range and 1,310 at 1000 yards for a total of 6,110 rounds. That's a bit more than most internet debaters manage to fire to support their reasoning.

Gilkes actions in .308 and .30-06 Match Rifles

Setting Standards
I have two pairs of identical rifles differing only in the chambering; one pair has Gilkes actions in Robertson synthetic stocks, the other pair has Borden actions in Eliseo tubegun stocks. One rifle in each pair is chambered in .308 and the other in .30-06. Clark Fay used the same two reamers for each pair of rifles; the .30-06 with the PTG Serengeti match reamer and the .308 with a tight-neck, slightly long-throat reamer we worked up together. All four rifles have Warner rear sights, Riles front sights and a roughly similar number of rounds fired through their barrels. Those four rifles form the basis for my comparison of the two cartridges for NRA Highpower prone shooting. As an added point of interest, I've also compared the scores from the .308 and the .30-06 to the scores I've fired with my 6XC rifles in order to compare the old stalwarts against a fairly representative modern sub-caliber cartridge.

Eliseo CSS Tubeguns with Borden actions - .308 and .30-06
Most shooters who ask me about the .30-06 want to know whether the recoil is uncomfortable; the short answer is no. Although the straight-line design of the tubegun stocks seems to reduce the felt recoil a bit, it isn't bothersome in either type of stock. Compared to the .308, with the same bullet weight, you feel more pressure from the handstop, but not particularly more in the shoulder. The more significant difference is the amount of muzzle movement during barrel time; when the shot breaks while the barrel is still moving, the .30-06 will usually deliver the shot a bit further from center than the .308 which has less muzzle movement. As long as the shot is broken with a still muzzle and with good follow-through, the increased muzzle movement during barrel time won't be a problem. Uncomfortable recoil isn't a concern, but the need for highly refined shot execution skills is both the limitation and the opportunity presented by the .30-06.

Gilkes 6XC and BAT 6XC
Let's get on with the score comparison and then we'll give it a bit of analysis. At the bottom of the article you'll find a series of charts, these contain all of the scores that I've fired in competition since January of 2009 with these rifles - no scores were omitted. Some days were windy, some were brutally windy, a few were calm, some days I was trying new loads or new bullets, some I used well known loads. The point is that everything is in the mix and over a large number of matches, it averages out quite well.

Mid-Range Comparison
In NRA Mid-Range matches (500 and 600 yards), the average score and percentage of possible score for each cartridge was as follows:

.308 - 597-36X (99.5%) 960 rounds fired
6XC - 596-35X (99.3%) 1260 rounds fired
.30-06 -  595-31X (99.2%) 2580 rounds fired

Interestingly, the high X count (44X) was reached with all three cartridges. During the time period under review, I shot three scores of 600 with the .308, one 600 with the 6XC and none with the .30-06. Over the years I've shot 23 scores of 600, but only one was with a .30-06 and that was about 15 years ago.

If we look at the score averages, the .308 comes out on top at the Mid-Range distances. The average for the .308 is composed of a smaller number of scores because I tend to shoot the .30-06 more often, but I think it's a large enough sample to be reasonably accurate so the Mid-Range win goes to the .308 by 0.3% of the possible score. By the way, notice the the 6XC, as good as it is, simply straddles the .30 caliber cartridges, it is not the winner - that may surprise some people. When you factor in the shorter barrel life of a 6XC compared to the .30's, that becomes something to really consider when selecting a cartridge for Mid-Range matches.

Long-Range Comparison
I rarely shoot the .308 in matches that are only 1000 yards; most of my 1000 yard .308 shooting is done in Palma matches which include 800, 900 and 1000 yards. As most of you know, the .30-06 and 6XC can't be used in Palma matches. This creates a small difficulty in score comparisons because Palma matches have 15 shot stages and 1000 yard matches have 20 shot stages. To make the comparison useful, the Long-Range results are presented only as a percentage of the possible score and the 800 and 900 yard stages of Palma matches were not included in the comparison (although they are shown in the charts, they were not used in calculating the averages).

In NRA Long-Range and Palma matches, the average percentage of possible score for each cartridge at 1000 yards was as follows:

6XC - 98.9%, 360 rounds fired
.30-06 - 97.7%, 460 rounds fired
.308 - 97.3%, 490 rounds fired

As you can see, the .308 went from the top of the list at Mid-Range to the bottom at Long-Range. This isn't too surprising when one considers its limited case capacity for the bullet weights typically used in Long-Range shooting. They just run out of steam and dip perilously close to the transonic range as they approach 1000 yards of flight (see this earlier article for more information on transonic problems). The extra 150 fps or so that can be safely obtained from the .30-06 case really pays off at 1000 yards. Unsurprisingly, the 6XC which moves light, high BC bullets at an even higher MV than either of the .30's comes out on top. I used the 6XC to win the Arizona Long-Range State Championship a few years ago and remain confident that it is a top choice for NRA Long-Range competition.

A Few Concluding Thoughts
Although I keep a log of all my scores, I hadn't calculated the percentages prior to preparing this article. However, I wasn't particularly surprised by the results; the .308 has always been a tremendously accurate cartridge at 600 yards, Mid's conclusions from 1963 remain valid today. I was a bit surprised that the 6XC wasn't the top dog at Mid-Range, but that simply shows that our pre-conceptions can be wrong and data matters. At Long-Range, the cartridges finished in the exact order that I would have predicted. I know the 6XC is a great LR cartridge, and my results with the .30-06 at 1000 have been very satisfying, so there were no surprises there. That's not to say some other people won't be surprised by the outcome!

So how much do these differences matter? It depends a bit on your level of shooting. Many of the Mid-Range matches shown in the charts were won or lost by a point, plenty more came down to the X count. When you're fighting for the overall win at 500 or 600 yards, every point and every X makes a difference. However, all three cartridges are remarkably close; I believe this reflects the fact that ballistics are relatively less important than pure shooter skill in Mid-Range shooting. With the same shooter behind the buttplate for all three cartridges, the results are predictably close. As the charts show, I shoot the .30-06 a lot more than the other cartridges, the simple reason is that the extra challenge of doing it with the .30-06 makes the wins all the sweeter, so I keep at it.

In the Long-Range matches, the spread between the cartridges is a little bigger, reflecting the increased importance of ballistics when the range gets stretched to the maximum. So even with the same shooter firing all the rifles, the differences become more pronounced. Many modern-day competitors look down on the .30-06 as a long range cartridge, but I'll definitely say that if you want a good shooting cartridge with excellent barrel life and a huge choice of components, you can't do much better than the .30-06 for all around use.










Related Articles
The Logical .30-06
Accuracy Secrets of the .30-06 - Part 1
US National Match Ammunition

For more related articles, please go to the Articles Index

Franklin Roosevelt shooting a 1903 Springfield at the Marine Corps range - 1917
 

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