Match Rifle Loads for the 6 mm HAGAR

                Okay, I admit it.  I'm getting older.  I'm not old, yet, but just older.  For those of you who have been through this, you will already know that, for the most part, the change is very subtle.  One day you wake up and you realize that you cannot do something you could do before. Right?  This same sort of subtle change affects one's shooting as well.

The sight radius of an AR-15 service rifle is only 20 inches

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                And, now for another admission; I've never been a great prone 600 yard shooter.  I have always been an adequate 600 yard shooter (I do hold a Master classification in high power rifle), but it was mastery of the other three stages (200 yard standing slow fire, 200 yard sitting rapid fire, and 300 yard prone rapid fire) that really got me that Master card.  For many who cannot master the 600 yard line, the blames lies in the inability to call the wind; however, that was never my problem.  In fact, I've called the wind the last four years for the Louisiana State Service Rifle Team at the National Matches at Camp Perry in Ohio.

                 For me, the problem lately has been that by the time I get back to the 600 yard line, my older eyes are worn out.  The short sight radius of the service rifle, combined with my tired, old eyes, leads to the front sight disappearing sometime around shot eight of the 22 shot string (two sighting shots and 20 shots for record).  A disappearing sight is not conducive to high scores, as I tend to string shots high and low because I cannot seem to get the post front sight on my service rifle to be centered in the target mass.  For those of you who have never fired an AR-15 service rifle, the sight radius (the distance between the rear sight and the front sight) is a mere 20 inches.  And, although in the picture below the post and target are both in clear focus, in fact it is quite impossible in real life to get both the post and target in focus.

The sight picture through the rear peep sight of the AR15 with the post front sight centered underneath the target is called a "6 O'clock Hold."

Indeed, one of the most difficult lessons for a high power rifle novice is to convince him or her to let the target blur and to keep the front sight in focus.  Although it sounds simple, in reality it is really hard.  One's mind wants to see that target, but keeping the target in focus is a sure way to lose points as the front post wanders out of the center of the target.

The shooter can either keep the target in focus (left) or the front sight in focus (right).  The preferred sight picture is the one at right, which is hard for older eyes.

                A lot of time, money, and effort has gone into shooting glasses and lenses that insert into the rear sight hood of my service rifle (yes, the CMP does allow one to insert a lens into the rear sight hood).  Although I'm not giving up on shooting my service rifle, a recent incident at the monthly mid-range prone match at Palo Alto Rifle & Pistol Club convinced me it was time.  Time for what?  Read on.  The format for the mid-range prone match is three separate strings of 22 shots (two sighting shots and 20 shots for record) all from the prone position at 600 yards.  To say the least, my first two strings of fire with my service rifle were downright horrible.  I was just about to give up and not waste the ammunition shooting the third string when my good friend, Buck Kliebert, suggested I shoot his Palma rifle.  I greedily accepted his offer and fired a very respectable score with a rifle I had never shot before!

                Palma is another discipline of high power rifle that involves shooting matches at 800, 900, and 1,000 yards.  There are several major differences between a Palma rifle and a service rifle, but for the sake of this article, the main difference between the service rifle I was shooting and Buck's Palma rifle is the sights.  The facts are that (1) the service rifle sights are battle sights that have been "improved" for use in shooting matches, and (2) the Palma sights are pure target shooting sights by design.  The difference in the sights is dramatic, particularly for anyone over 40 years of age!

The sights found on the service and match rifles are shown.  In panel A, the standard service rifle front sight is shown with a narrow post.  In panel B, the modified rear sight is shown with a corrective lens in the hood.  Panel C and D show the Stallings Machine "Rightsight."  The iris is adjustable. In panel E, the Phoenix side-mount rear sight is shown.

                After firing Buck's Palma rifle, I immediately decided, "I've got to build one of these."  I discussed this with Buck and friends, Bob and Bill Jenkins, who are both high master high power rifle shooters.  Bob and Bill both urged me not to build a Palma rifle, but instead to build a "space gun," which would allow me to shoot both the mid-range (600 yards) and long range (800, 900, and 1,000 yards) prone matches, and also to shoot "across-the-course" matches (XTC matches are shot at 200, 300, and 600 yards).  Perfect!  The three outstanding shooters had solved two problems for me: (1) I would be able to shoot the longer range prone matches and (2) continue to shoot the XTC matches I love so much.  Further, the rifle would be built on the very familiar AR-15 platform.

                Although it is easy to say, "I'm going to build a space gun," in reality there are so many choices that the process can be overwhelming.  In my case, I wanted a rifle that I could use XTC, so many of the decisions were easier.  The first decision was to determine which caliber I would use.  The path of least resistance would have been to use .223 Remington.  I have shot tens of thousands of .223 rounds through my service rifles over the last 15 years. I have a progressive press set up to load short line rounds (200 and 300 yards) with Berger 77 Gr. Match OTC bullets and 24.2 Gr. of Varget with Winchester Small Rifle primers (cartridge overall length, COAL, of 2.260" to fit in the standard AR-15 magazine).  I have a Redding .223 caliber competition die set to seat Berger 82 Gr. match BT target bullets over 24.2 Gr. of Varget with Federal Premium Gold Medal Match  GM205M primers for the long line (COAL of 2.445" in my service rifle). [WARNING! Both of these loads exceed recommended pressure limits and the reader must not use these loads without first reducing powder charges by at least 10% and working up to this load.  Note that my rifle has a Wylde chamber, and not a SAAMI .223 Remington chamber.  These loads are UNSAFE in a standard .223 Remington chamber!]  But, Bob Jenkins recommended I go elsewhere.  He recommended the relatively new 6 mm Hagar round.  Unlike the .233 Remington, which has been a standardized cartridge for many years, the 6 mm Hagar has yet to be recognized with SAAMI standardization.

Pictured from left to right are empty cases for the 6 mm BR Norma, 6 mm Hagar, 6.8 mm Remington SPC, and .223 Remington.  The loaded cartridges are (left to right) .223 Remington loaded to magazine length with the Berger 77 Gr. OTC Match bullet, .223 Remington loaded with the Berger 82 Gr. BTHP bullet, 6 mm Hagar loaded to magazine length with the Berger 95 Gr. Hybrid bullet, and 6 mm Hagar loaded with the Berger 105 Gr. BTHP bullet.

The 6 mm Hagar is built on the same case as the .30 Remington and 6.8 mm Remington SPC, with substantially more case capacity than the .223 Remington.  The .223 Remington holds 28.8 Gr. of water, whereas the 6 mm Hagar holds 37.5 Gr., an increase of 30% in capacity.  This additional case capacity allows one to propel heavier bullets, with their concomitant higher ballistic coefficients, at comparable velocities.  As mentioned previously, most XTC shooters choose to shoot 75 or 77 Gr. bullets at the 200 and 300 yard lines.  These bullets are designed to allow the shooter to seat the bullet into the .223 Remington case to a COAL of 2.260, which is the maximum length that will fit into the AR-15 magazine.  Magazine length rounds are necessary, as there are rapid fire strings at both the 200 and 300 yard lines, and the rules of the game require the shooter to fire these rounds from a magazine.

In my rifle, I get 2853 FPS from Berger 77 Gr. Match OTC bullets.  With the 6 mm Hagar, I can load Berger 95 Gr. Classic Hunter bullets to magazine length, and get the same velocity.  However, the 95 Gr. bullet is 23.4% heavier than the 77 Gr. bullet, with a 14% increase in ballistic coefficient from 0.376 to 0.427.  In a 10 MPH full value crosswind (blowing perpendicular from left to right or right to left across the path of the bullet), the 77 Gr. bullet will drift 8 inches (2.5 MOA) at 300 yards versus 6 inches (2 MOA) for the 95 Gr. bullet. While this may not seem like a lot to the uninitiated reader, the “X-ring” on the 300 yard target is only 3 inches wide, and the shooter typically will not have time to make adjustments to his or her sights during rapid fire shooting in which the competitor must fire 10 rounds in 70 seconds with a mandatory magazine change (when time begins, the shooter loads a magazine containing 2 rounds, fires those two rounds, and then changes to a magazine containing the remaining 8 rounds, and then fires those).  A small change in wind velocity can have huge implications in one's score with lighter bullets.

The difference is far more dramatic for the “long line” ammunition.  All firing from the 600 yard line is slow fire, where each round must be loaded into the rifle one at a time.  This allows the competitor to fire long bullets that are seated out much too far to fit into the magazine.  My 600 yard load for the .223 Remington uses the Berger 82 Gr. match BT target bullet seated to a COAL of 2.445 inches leaving the muzzle at 2750 FPS.  In the 6 mm Hagar, I can drive the Berger 105 Gr. BTHP to 2872 FPS.  The 105 Gr. bullet is 28% heavier than the 82 Gr. bullet, with an increase in the ballistic coefficient of 27%.  At 600 Yards with a 10 MPH full value wind, the 82 Gr. bullet will drift 31 inches (5 MOA), whereas the 105 Gr. BTHP bullet will drift less than 25 inches (4 MOA).  The "X-ring" on a 600 yard target is only 6 inches wide, so, again, a small change in wind velocity can have a huge impact on the location of the shot for small bullets with relatively low ballistic coefficients.

Okay, I see you scratching your head at this point and asking the obvious question.  "If heavier bullets and high ballistic coefficients are better, why did you build a rifle in 6 mm instead of .30 caliber (7.62 mm)?"  That indeed is a fair question and the answer can be found in the original requirements.  I wanted to build a space gun based on the very familiar (to me) AR-15 platform.  The AR-15 platform is limited in the length, diameter, and power of the cartridge that it can accept, and any .30 caliber cartridge is going to have a seriously short case to caliber ratio, and be vastly underpowered.  The 6 mm Hagar is an excellent compromise, using a heavier bullet in a standard, necked-down .30 Remington case.

This 10-shot group was fired at 100 yards using the Berger 105 Gr. BTHP bullet with 29.1 Gr. Hodgdon Varget and a GM205M primer in Hornady cases.  Note that the single high left shot in the group was called "out" by the author as soon as it was fired.

 So far, my tests with my new 6 mm Hagar space gun have proven that the Berger 105 Gr. BTHP bullet is extremely accurate using 29.1 to 29.7 Gr. of Hodgdon Varget, and anyone would be more than satisfied to use this load at 600 yards.  However, Berger has an even better 105 Gr. bullet than the BTHP.  Berger's new 105 Gr. Hybrid bullet has a ballistic coefficient of 0.547 versus 0.493 for the 105 Gr. BTHP bullet.  As can be seen in the accompany table, the Hybrid bullet is longer and the ogive has been pushed forward; however, the longer bullet has a longer nose length.  These features result in a much improved ballistic coefficient in a bullet of the same weight.  Although the bullet promises better long range accuracy, so far my tests have been completely unsatisfactory.  I have not been able to find a load that results in acceptable accuracy.  For instance, the 0.36 inch spread at 100 yards with the 105 Gr. BTHP would result in an expected spread of 2.2 inches at 600 yards, which is more than adequate to keep the bullet in the 6 inch X-ring.  On the other hand, the best accuracy I have achieved with the 105 Gr. Hybrid bullet is 0.80 inches at 100 yards, which would result in an expected extreme spread of almost 5 inches at 600 yards.  The extreme spread is almost as big as the X-ring!  But, fear not!  I will keep on trying until I either get the 105 Gr. Hybrid bullet to shoot well, or I'll accept the slightly lower ballistic coefficient of the 105 Gr. BTHP bullet and use it for all of my 600 yard shooting.

So, what are the components used to build the new space gun?  The upper assembly was purchased from accomplished gunsmith and high power rifle competitor John Holliger of White Oak Precision.  As of the writing of this article, John was selling his 6 mm Hagar upper assembly exclusively through Creedmor Sports.  The upper is built by John with a 28-inch stainless-steel Criterion match barrel with a 1 in 8 twist.  I decided that I wanted an even longer sight radius, so I extended that 28-inch barrel by attaching Norm Houle's 6-inch "bloop" tube onto the end of my barrel.  The tube assembly has a clamp-on locating ring plus a clamp-on "bloop" tube that positively indexes off a tapered pin that protrudes from the locating ring. The locating ring is light but very strong and absolutely stays put when one clamps it on the barrel end. The "bloop" tube part of the assembly has two clamp-on screws. With the "bloop" tube installed, the sight radius becomes a whopping 37.5 inches (take that 50 year old presbyopic eyes)!

The "bloop" tube is attached to the barrel.

If the barrel of a rifle is its heart, then surely the trigger is the brains of the entire operation.  A good trigger cannot be understated on a match rifle.  I've been using the Geissele (pronounced guys-lee) service rifle trigger for several years and am ecstatic with its performance.  In service rifle competition, the trigger must be able to

Bullet COAL Powder Charge Muzzle Velocity No. Shots in Group Group Size Berger 105 Gr. Boat tail Target  2.445 Varget 28.5 2754 ± 12 5 0.37  (#24428) BCG1 = 0.493, BCG7 = 0.253 Varget 29.1 2792 ± 8 10 0.36 Varget 29.4 2812 ± 8 4 0.37 Varget 29.7 2834 ± 10 10 0.36 Berger 105 Gr. Match Hybrid Target  2.445 Varget 29.4 2760 ± 19 10 0.84 (#24433) BCG1 = 0.547 BCG7 = 0.278 Varget 29.4 2801 ± 11 3 0.75 IMR8208XBR 28.2 2815 ± 6 3 0.87 H4895 28.6 2851 ± 4 3 1.47 AA2495 28.0 2794 ± 6 4 0.77 AA2520 29.7 2897 ± 9 10 0.87 Reloader 15 29.7 2867 ± 4 10 0.80 IMR4320 29.8 2893 ± 6 10 0.91 BL-C(2) 30.7 2885 ± 18 3 0.99 Berger 95 Gr. Hybrid 2.285 Varget 29.0 2803 ± 17 10 1.25 (#24570) BCG1 = 0.427 BCG7 = 0.219 Varget 29.0 2751 ± 17 10 1.61 Reloader 15 29.4 2849 ± 19 10 0.61 IMR4320 29.4 2848 ± 15 10 1.00 Hornady 87 Gr. V-MAX 2.285 Varget 29.8 2886 ± 5 3 0.91 (#22440) BCG1 = 0.400 BCG7 = 0.199 Hornady 75 Gr. V-MAX 2.285 Varget 31.7 3148 ± 28 3 1.37 (#22420) BCG1 = 0.330 BCG7 = 0.160 Varget 31.7 3148 ± 28 3 0.89 Abbreviations: COAL, cartridge overall length; BCG1, ballistic coefficient using G1 drag  function; BCG7, ballistic coefficient using G7 drag function Primers Used: Long range loads with 105 Gr. bullets used Federal GM205M Short range loads with 75, 87, or 95 Gr. bullets used Remington 7 1/2

support 4.5 pounds of weight without "breaking."  However, with a match rifle, any safe weight is allowed.  I chose to install the Geissele Hi-Speed Match Rifle Trigger in my new rifle.  The Geissele Hi-Speed Match Rifle Trigger has a 1^st stage of 1.5 to 2.5 pounds and a 2^nd stage of 0.4 to 0.9 pounds. Because the trigger is designed for NRA High Power Match Rifle competition with highly modified, match-grade AR-15 rifles, its adjustability, lighter 1^st and 2^nd stage pull weights, and fast lock time enhances trigger control and accuracy while the full-power hammer spring provides uniform primer ignition for more consistent bullet velocity.  In my rifle, the trigger is set at 2.5 pounds, which is about as light as anyone would want for XTC matches where rapid fire strings are shot.

The Geissele Hi-Speed Match Rifle Trigger breaks at a crisp 2.5 pounds.

The trigger was installed into an AeroPrecision lower receiver along with a White Oak Armament lower parts kit.  I know that many shooters get completely "wrapped around the axel" about lower receivers.  DON'T!  I have used lower receivers from dozens of manufacturers over the years and I can tell you that I have not found a bad one yet.  I have service rifles built on Bushmaster, Rock River Arms, and Armalite lower receivers, and hunting/zombie rifles built on other receivers. If you want to build your own space gun and you already have a lower receiver, use it.  If you are planning to purchase one for your project, buy the cheapest alloy lower receiver you can find and build away!

For the buttstock of my new rifle I chose the excellent White Oak Precision adjustable buttstock for a right handed shooter (yes, they make a left hand version as well).  The stock has an easy to use thumbwheel adjustment for the cheek rest, and reference marks machined on the buffer tube and buttplate length of pull rod for repeatable adjustments.  The cheekpiece housing and buttplate hanger are aluminum with an anodized finish and the buffer tube, length of pull rod and buttplate backer are made of steel for added weight.  The complete assembly, with buffer and spring weighs four pounds.  The cheekpiece does interfere with the operation of the standard AR-15 charging handle, so a bolt carrier-mounted handle is necessary.  The White Oak Precision upper assembly comes with a bolt carrier-mounted handle.  The White Oak Precision Adjustable Buttstock is adjustable for:

1. Buttplate Height
2. Cast-Off/On, 0-2"
3. Length of Pull 9-16" (AR-15 measured from trigger)
4. Buttplate Yaw
5. Camber
6. Cheekpiece Height

Although I specifically chose this buttstock because of the numerous possible adjustments, this has proven to be a double edged sword.  The learning curve for getting all of the correct settings in the three positions of XTC shooting (standing, sitting, and prone) was steep and it took quite a while to become comfortable in all three positions.

Item Manufactuer Supplier  Cost Upper Assembly White Oak Precision Creedmor Sports  $ 1,080.00 Bloop Tube Norm Houle White Oak Armament  $    135.00 Trigger Geisele Automatics White Oak Armament  $    279.00 Lower Receiver AeroPrecision Brownells  $       85.00 Lower Parts Kit Various White Oak Armament  $       40.30 Adjustable Buttstock White Oak Precision White Oak Armament  $    425.00 Front Sight Stallings Machine Stallings Machine  $    379.00 Rear Sight Phoenix Precision Phoenix Precision  $    408.00 Rear Sight Base Lipski White Oak Armament  $       64.50 Rear Sight Iris Gehmann Champion's Choice  $       51.00 Anti-glare Tube Gehmann Champion's Choice  $       14.00  $ 2,960.80

When choosing the front sight, I spoke to Buck Kliebert about what he was using on his rifles.  He suggested the Stallings Machine Rightsight.  The Rightsight is built around a 30mm front sight tube, and was developed for high power rifle competition to have the best possible sight picture allowed by iron sight rules.  The Rightsight comes with an adjustable iris made by Gehmann, and are available in 4 sizes: 2.4 - 4.4 mm, 2.9 - 4.9 mm, 4.0 - 6.0 mm, and 5.5 - 7.5 mm.  Given that this was my first XTC match rifle, I called Wayne Fourche at Stallings Machine and discussed my needs.  He suggested that I use the 4.0 - 6.0 mm for XTC competition.  The adjustable iris is the same as the Gehmann 520 iris in a larger frame made to fit the Rightsight and other 30mm sights.  The Rightsight also includes a 30mm, 0.5 diopter Crizal Alize anti-reflective lens, which enlarges the target when one looks through the sight.  The base onto which the Rightsight is mounted has 50 MOA adjustment, allowing me to move the front sight when moving from 300 yards to 600 yards, with only minimal adjustments to the rear sight.

The Stallings Machine Rightsight was chosen for its flexibility, as it may be used for XTC, Mid-Range, or Long Range competitions.

 For the rear sight, I used the Phoenix Precision rear sight with adjustment knobs that rotate in the same direction as a service rifle sight.  For the uninitiated, a brief explanation is in order.  The standard match rifle sights adjust just like a rifle scope.  To move the impact of the bullet to the right, match sights and rifle scopes are adjusted counterclockwise.  However, on a service rifle, to move the bullet impact to the right the shooter would adjust the knob clockwise.  For me, who has been shooting service rifle competition for decades, the chose was a "no-brainer."  For me, turning the knob clockwise will ALWAYS move the bullet impact to the right.  I'm far too old to learn the new trick of adjusting the other way, so I purchased a match sight with service rifle adjustments.  The sight was originally purchased years ago by me for a different project, and unfortunately is the side mount version.  For the space gun it would have been better to have a top mount sight.  To turn the side mount sight into a top mount sight, I purchased a Lipski rear sight base.

The rear sight comes without an iris so that the shooter can set up the sight as he or she wishes.  I chose to install a Gehmann 0.5 - 3.0 mm iris on the sight. The Gehmann system of rear sight irises is based upon their patented fixed-seat iris design constructed with tempered stainless steel leaves attached to the iris body. All irises are built upon this principle, and all additional features connected to and within iris combinations benefit from this principle. As a result, the peephole seen by the shooter is absolutely circular throughout the full range of adjustments.  The iris is very important to the shooter, as it enables the shooter to achieve an extended depth of optical field to clearly see both the front sight and the target picture at the same time.  All internal and external black surfaces are manufactured to give absolutely minimal light reflection, which is another cause of sight picture loss when shooting XTC in bright sunlight.  And, speaking of bright sunlight, the final touch was to place a Gehmann 35 mm anti-glare tube on the front of the rear sight.

So, now that the rifle is finished, the hard part has begun.  As luck would have it, though, the hard part is also the fun part!  I'm slowly climbing that learning curve to get familiar and comfortable with the rifle in all three positions.  So far, my standing scores have gone up nicely, mainly because the long sight radius is so forgiving as that front sight dances around the target.  In contrast, my sitting position is a freaking mess!  My scores have dipped dramatically, and will continue to be poor until I find that sweet spot.  Finally, my all important prone position is getting better each time I fire the rifle, and it won't be long until I won't have an excuse for a shot out of the 10-ring.

The completed rifle weighs 14.8 lbs. and is 57 in. long.

                Now, enter my 50 year old eyes.  As evidenced by the racks of "cheater" glasses at any Walmart or pharmacy, it gets harder and harder to see things up close as one ages.  That target 600 yards away is a whole lot easier to keep in focus than the front sight that is only 20 inches away.  So, my tired, old eyes give up and the front sight just disappears.  And, as I work hard to try and see it, the target disappears.  I don't mean it fades or blurs.  I mean it freaking disappears!  So, my new sight picture is a quite out of focus target and quite out of focus front sight.  Argh!