Black Hills 223 Remington 75 Grain Match HP Ammunition Accuracy Evaluation

Molon

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Black Hills 223 Remington 75 Grain Match HP Ammunition

Blue Box versus Red Box





black_hills_boxes_02_resized_darker_bord-1895277.jpg





The difference between Black Hills’ red box and blue box ammunition lies primarily with the brass case. Red box ammunition is newly manufactured using virgin brass. Blue box ammunition is referred to as “remanufactured” because is uses once fired brass that has been resized. This enables Black Hills to sell the blue box ammunition at a reduced price compared to their red box ammunition.


Black Hills’ 75 grain Match HP (hollow point) ammunition is loaded with Hornady’s 75 grain BTHP Match bullet with a cannelure (commonly referred to as the “T1C”) and both the red box and blue box loads have a crimp at the case mouth. Both loads are charged with “ball powder.” The nominal OAL for the red box cartridges ran approximately 2.245” and for the blue box cartridges it was closer to 2.250”.






t1_t2_comparision_03-2254290.jpg






The brass cases used in the red box ammo have sealed primers and the headstamp of most lots of this load read “BHA 223 MATCH.” These virgin cases have a nominal length of 1.755”.

The brass cases used in the blue box load tend to be a mix of once fired Lake City and Winchester brass. The military primer crimps has been removed by the reaming method. The blue box loads do not have sealed primers.

Black Hills does not perform a “trim to length” operation on the resized cases used in the blue box ammunition. As a result, many of the cases are longer than the SAAMI recommended maximum length of 1.760”. Several of the cases that I measured had a length of 1.775”. This could potentially cause problems in a barrel with a minimum length chamber, though no malfunctions of any kind were experienced during the testing of this ammunition. (Using a Sinclair chamber length gauge, I determined the chambers of my Colt barrels have a length of 1.780”.)

Both loads were chronographed using four different length barrels. All of the Colt barrels used in testing have a NATO chamber and a 1:7” twist. The 24” Krieger barrel has a 5.56 Match chamber and has a twist rate of 1:7.7”. On their web-site, Black Hills advertises a muzzle velocity of 2,750 fps for these loads, but they do not state the barrel length associated with this velocity, though the industry standard calls for a 24” barrel.

Chronographing was conducted using an Oehler 35-P chronograph with “proof screen” technology. The Oehler 35P chronograph is actually two chronographs in one package that takes two separate chronograph readings for each shot and then has its onboard computer analyze the data to determine if there is any statistically significant difference between the two readings. If there is a statistically significant difference in the readings, the chronograph “flags” the shot to let you know that the data is invalid. There was no invalid data flagged during this testing.


The velocity stated below is the muzzle velocity as calculated from the instrumental velocity using Oehler’s Ballistic Explorer software program. The string of fire consisted of 10 rounds over the chronograph.


Each round was single-loaded and cycled into the chamber from a magazine fitted with a single-load follower. The bolt locked-back after each shot allowing the chamber to cool in between each shot. This technique was used to mitigate the possible influence of “chamber-soak” on velocity data. Each new shot was fired in a consistent manner after hitting the bolt release. Atmospheric conditions were monitored and recorded using a Kestrel 4000 Pocket Weather Tracker.


Atmospheric conditions

Average temperature- 80 degrees F
Humidity - 48%
Barometric pressure – 29.04
Elevation- 960 feet above sea level






black_hills_75_mhp_barrel_comparison_of_-2254513.jpg





While chronographing the Black Hills loads through the 24” Krieger barrel, I also chronographed three of Hornady’s SAAMI pressure, 75 grain loads that use the T1C bullet for comparison.




black_hills_and_hornday_velocity_compari-2254516.jpg





For additional comparison, I also fired the Black Hills loads side-by-side with some of the Hornady 75 grain SAAMI pressure loads from the 20” Colt A2 barrel.



Colt_20_inch_muzzle_velocities_03-2254521.jpg






100 yard Accuracy Evaluation of Black Hills 75 grain MHP

Red Box versus Blue Box





As previously discussed in this thread, the primary difference between Black Hills' red box and blue box ammunition lies with the brass case. Red box ammunition uses virgin brass, while blue box ammunition uses once fired brass that has been resized.

The test-vehicle for this accuracy evaluation was a semi-automatic AR-15 with a 24” stainless-steel Kreiger VarMatch barrel, with a 1:7.7” twist, installed on a LaRue Tactical Stealth upper receiver.

I conducted an accuracy (technically, precision) evaluation of the Black Hills 75 grain Match HP ammunition following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group-reduction techniques (e.g. fliers, target movement, Butterfly Shots).

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Also, a control group was fired from the test-rifle used in the evaluation using match-grade, hand-loaded ammunition; in order to demonstrate the capability of the barrel.


All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrel used in the evaluation was free-floated. The free-float handguards of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold Competition Series Scope which was adjusted to be parallax-free at 100 yards. A mirage shield was used. Wind conditions on the shooting range were continuously monitored using a Wind Probe.





Control Groups


Prior to testing the Black Hills ammunition, I obtained three 10-shot groups of a control load consisting of hand-loaded Sierra 55 grain BlitzKings (at a distance of 100 yards of course.) Those three groups had extreme spreads of:


0.547”

0.57”

0.69”


for an average extreme spread of 0.602”. The three 10-shot groups were overlayed on each using RSI Shooting Lab to obtain a 30-shot composite group that had a mean radius of 0.19”.




Red Box



Following the same procedures used with the control load, three 10-shot groups of the Black Hills red box 75 grain MHP fired from 100 yards were obtained. Their extreme spreads measured:


0.96”

1.00”

1.04”


for an average extreme spread of 1.00”. As with the control load, the three 10-shot groups from the red box ammunition were over-layed on each other to obtain a 30-shot composite group with a mean radius of 0.32”.






Blue Box


In the same manner as above, three 10-shot groups of the blue box 75 grain MHP were obtained from 100 yards with extreme spreads of:


1.11”

1.16”

1.16”


for an average extreme spread of 1.14”. Those three 10-shot groups overlayed on each other had a mean radius of 0.37”. Here are the 30-shot composite groups side-by-side for comparison.




black_hills_75_mhp_composite_comparisons-2254525.jpg






Lastly, for any Internet Commandos in our viewing audience, I fired a 3-shot group of the red box 75 grain MHP from 100 yards. That group measured 0.276”.
icon_smile_big.gif





3_shot_group_of_red_box_75_mhp_02-2254530.jpg








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..
 
Last edited:

Molon

Sergeant of the Hide
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What loads have you found to be most precise


Federal 69 grain Gold Medal Match Ammunition Accuracy



69_gold_medal_boxes_02-1287986.jpg




In their 1984 catalog, Sierra Bullets introduced the .22 caliber (0.224”) 69 grain MatchKing HPBT (hollow point boat tail) bullet (#1380). The 69 grain MatchKing was “developed as a target bullet for testing by military teams in the new M16A2 rifle”* and the bullet became a popular choice for shooters using the AR-15 in High Power Rifle Competition.



69_matchking_bullet_box_02_resized-1287991.jpg




While the US military had experimented with “heavy” FMJ (full metal jacket) bullets for the 5.56mm cartridge as far back as the mid-1960s, (the Colt/Federal 5.56mm 68 grain FMJ) the .22 caliber 69 grain MatchKing was the first heavy OTM (open-tip match) bullet that was available to the general public as a reloading component for 223 Remington/5.56mm cartridges. (Hornady’s 68 grain OTM bullet (#2278) wasn’t introduced until approximately two years later.)



colt_federal_68_grain_cartridge_01_JPG-1287998.jpg




federal_69_gold_medal_cartridge_and_pull-1288000.jpg




In their 1989 ammunition catalog, the Federal Cartridge Company debuted an addition to its “Match” line-up of factory loaded rifle ammunition; a 223 Remington load topped with none other than the Sierra 69 grain MatchKing (223M). In their 1992 catalog, Federal expanded the nomenclature for this load to “Premium Match” (P223M) and in their 1993 catalog it became “Gold Medal Match” (GM223M) as part of a marketing campaign capitalizing on the USA Shooting Team’s success in the Barcelona Olympics using Federal ammunition.

It’s interesting to note that pertaining to the accuracy/precision development and multifaceted testing of the Federal ammunition that helped the US Olympians win gold and silver medals in Barcelona, Federal’s Director of Product Engineering, Dave Longren, had this to say:

“The standard test string was three 10-shot groups, with the most attention paid to the 30-shot composite. When you’re working at this level, the traditional five 5-shot group test simply doesn’t give you statistically valid results.”**



69_gold_medal_box_05-1287985.jpg




federal_69_gold_medal_cartridge__02-1287999.jpg




The 69 grain Sierra MatchKings loaded in the lot of Federal Gold Medal Match ammunition that I evaluated for this article had a nominal length of 0.890”. The nominal cartridge OAL of this load was 2.248”. Through some simple testing, I determined that the 69 grain MatchKing has a specific gravity of approximately 10.2.

According to Ballistic Performance of Rifle Bullets by Bryan Litz, the 69 grain MatchKing has an average G1 ballistic coefficient of 0.330 and an average G7 ballistic coefficient of 0.169. The same source states that the “recommended twist for optimal performance” of the 69 grain MatchKing “is 1:9.5” or faster.

The 69 grain MatchKings that top the Federal Gold Medal Match ammunition are loaded in Federal brass. The head stamp for this lot reads “FC 13 223 REM”. The rounds are primed with Federal Gold Medal Small Rifle Match Primers (GM205M). The primer pockets are crimped and sealed with a blue lacquer sealant.



gold_medal_brass_box_02_resized-1288003.jpg




gold_medal_primers_01_framed_JPG-1288004.jpg




69_gold_medal_case_head_02c-1287987.jpg




The case-mouths of this lot of Federal 69 grain Gold Medal Match ammunition are sealed with asphalt sealant. The case-mouths have a slight taper-crimp which produces a shallow circumferential crease in the bearing surface of the 69 grain MatchKings. The pic below shows a pulled bullet on the right (the crease in the bullet indicated by the red arrow) next to a virgin 69 grain MatchKing on the left.



69_matchking_crimed_bullet_04-1287992.jpg




This lot of ammunition is charged with a “ball powder” (though I have seen lots in the past that were charged with a short-cut extruded powder.) The squares in the red grid pictured below are 1/10th of an inch.



69_matchking_powder_02-1287993.jpg




Velocity


When it was first introduced, Federal advertised the muzzle velocity of the 69 grain Gold Medal Match ammunition as 3000 FPS. More recent advertising lists the muzzle velocity at 2950 FPS. These figures are from 24” barrels.



federal_gold_medal_catalog_snapshot_01_r-1288002.jpg




federal_godl_medal_box_velcoity_data_01_-1288001.jpg




I chronographed the Federal 69 grain Gold Medal Match ammunition from a semi-automatic AR-15 with a chrome-lined, NATO chambered 20” Colt M16A2 barrel with a 1:7” twist.



Colt_20_inch_A2_barrel_02_border-1287997.jpg




Chronographing was conducted using an Oehler 35-P chronograph with “proof screen” technology. The Oehler 35P chronograph is actually two chronographs in one package that takes two separate chronograph readings for each shot and then utilizes its onboard computer to analyze the data to determine if there is any statistically significant difference between the two readings. If there is a statistically significant difference in the readings, the chronograph “flags” the shot to let you know that the data is invalid. There was no invalid data flagged during this testing.

The velocities stated below are the muzzle velocities as calculated from the instrumental velocities using Oehler’s Ballistic Explorer software program. The strings of fire consisted of 10 rounds over the chronograph.



oehler_chronograph_32-1288012.jpg




oehler_computer_02-1288011.jpg




Each round was single-loaded and cycled into the chamber from a magazine fitted with a single-load follower. The bolt locked-back after each shot allowing the chamber to cool in between each shot. This technique was used to mitigate the possible influence of “chamber-soak” on velocity data. Each new shot was fired in a consistent manner after hitting the bolt release. Atmospheric conditions were monitored and recorded using a Kestrel 4000 Pocket Weather Tracker.



kestrel_4000_21-1288007.jpg




Atmospheric conditions

Temperature: 70 degrees F
Humidity: 76%
Barometric pressure: 30.14 inches of Hg
Elevation: 950 feet above sea level


The muzzle velocity for the 10-shot string of the Federal 69 grain Gold Medal Match ammunition fired from the 20” Colt barrel was 2732 FPS with a standard deviation of 16 FPS and a coefficient of variation of 0.59%.

For those of you who might not be familiar with the coefficient of variation (CV), it is the standard deviation, divided by the mean (average) muzzle velocity and then multiplied by 100 and expressed as a percentage. It allows for the comparison of the uniformity of velocity between loads in different velocity spectrums; e.g. 77 grain loads running around 2,650 fps compared to 55 grain loads running around 3,250 fps.

For comparison, the mil-spec for M193 allows for a coefficient of variation of approximately 1.2%, while one of my best 77 grain OTM hand-loads, with a muzzle velocity of 2639 PFS and a standard deviation of 4 FPS, has a coefficient of variation of 0.15%.



stnadard_deviation_of_4_fps_01-1288013.jpg




Over the last decade I’ve chronographed several other lots of the Federal 69 grain Gold Medal Match ammunition from a variety of barrels. The muzzle velocities of those lots are shown in the table below.



69_grain_gold_medal_velocity_table_53_rs-1287990.jpg




Accuracy


I conducted an accuracy (technically, precision) evaluation of the Federal 69 grain Gold Medal Match ammunition following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group-reduction techniques (e.g. fliers, target movement, Butterfly Shots).

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Also, a control group was fired from the test-rifle used in the evaluation using match-grade, hand-loaded ammunition; in order to demonstrate the capability of the barrel. Pictures of shot-groups are posted for documentation.

All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrel used in the evaluation was free-floated. The free-float handguards of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold Competition Series 45x45mm scope adjusted to be parallax-free at 100 yards. A mirage shield was attached to the top of the free-float handguard. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.



benchrest_krieger_rifle_02_JPG-1287996.jpg




The Wind Probe.

wind_probe_25_resized-1288014.jpg




The test vehicle for this accuracy evaluation was one of my semi-automatic precision AR-15s with a 24” Krieger barrel. The barrel has a 5.56mm Match chamber with a 1:7.7” twist. Prior to firing the 69 grain Gold Medal Match ammunition, I fired a 10-shot control group using match-grade hand-loads topped with the Barnes 85 grain Match Burner. That group had an extreme spread of 0.56”.



krieger_24_inch_barrel_with_highpower_ta-1288008.jpg




barnes_85_match_burner_handload_10_shot_-1287995.jpg





Three 10-shot groups of the 69 grain Gold Medal Match ammunition were fired in a row with the resulting extreme spreads:


0.67”
0.73”
0.67”


for a 10-shot group average extreme spread of 0.69”. The three 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius for the 30-shot composite group was 0.24”.

The smallest 10-shot group . . .



69_gold_medal_smallest_10_shot_group_01_-1287989.jpg




The 30-shot composite group . . .

69_gold_medal_composite_group_01-1287988.jpg




....



* Technical Staff. “Sierra .22 Cal. 69-gr. MatchKing.” American Rifleman Jan. 1984: 60-61. Print.



** Hunnicutt, Robert. “Ammo Good as Gold.” American Rifleman Nov. 1992: 32-33, 72-73. Print.





....
 

Molon

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Feb 26, 2020
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How do these compare to mk262 and the mk262 TMK loads.


Black Hills MK262 Mod1 Ammunition




black_hills_box_01_resized-1342439.jpg





The 77 grain MK262 ammunition produced by Black Hills Ammunition has been referred to as the most accurate mass-produced 5.56mm ammunition that has ever been type-classified and issued by the US military. Since its inception, genuine MK262 has been manufactured solely by Black Hills Ammunition. For years, MK262 was only available to the civilian population as “seconds,” but more recently Black Hills has made first-run production lots available on the commercial market. It is the first-run version of MK262 Mod 1 that I tested for this report.

MK262 Mod 1 is loaded in WCC 5.56mm brass and uses a cannelured version of the 77 grain Sierra MatchKing. The round is charged with a proprietary ball powder. The primer pockets are crimped and sealed. Contrary to erroneous information that has been posted on the Internet, MK262 Mod 1 does not have case-mouth sealant.




mk262_casemouth_no_sealant_01_resized-1342448.jpg





mk262_casemouth_no_sealant_02_resized-1342449.jpg





The 77 grain MK262 Mod 1 projectile compared to the M193 projectile.

mk262_canelure_vs_m193_03resized-1342447.jpg





MK262 powder. (The squares of the red grid measure 1/10 of an inch.)

mk262_mod_1_powder_01-1342451.jpg







Velocity


I chronographed the Black Hills 5.56mm MK262 Mod 1 ammunition from a semi-automatic AR-15 with a chrome-lined, NATO chambered 20” Colt M16A2 barrel.




Colt_20_inch_A2_barrel_02_border-1342441.jpg





Chronographing was conducted using an Oehler 35-P chronograph with “proof screen” technology. The Oehler 35P chronograph is actually two chronographs in one package that takes two separate chronograph readings for each shot and then has its onboard computer analyze the data to determine if there is any statistically significant difference between the two readings. If there is, the chronograph “flags” the shot to let you know that the data is invalid. There was no invalid data flagged during this testing.

The velocity stated below is the muzzle velocity as calculated from the instrumental velocity using Oehler’s Ballistic Explorer software program. The string of fire consisted of 10 rounds over the chronograph.





oehler_chronograph_32-1342454.jpg





oehler_computer_02-1342452.jpg





Each round was single-loaded and cycled into the chamber from a magazine fitted with a single-load follower. The bolt locked-back after each shot allowing the chamber to cool in between each shot. This technique was used to mitigate the possible influence of “chamber-soak” on velocity data. Each new shot was fired in a consistent manner after hitting the bolt release. Atmospheric conditions were monitored and recorded using a Kestrel 4000 Pocket Weather Tracker.



kestrel_4000_21-1342442.jpg





Atmospheric conditions

Temperature: 79 degrees F

Humidity: 37%

Barometric pressure: 30.12 inches of Hg

Elevation: 950 feet above sea level



The muzzle velocity for the 10-shot string of the Black Hills 5.56mm MK262 Mod 1 ammunition fired from the 20” Colt barrel was 2848 FPS with a standard deviation of 10 FPS and a coefficient of variation of 0.35%

For those of you who might not be familiar with the coefficient of variation (CV), it is the standard deviation, divided by the mean (average) muzzle velocity and then multiplied by 100 and expressed as a percentage. It allows for the comparison of the uniformity of velocity between loads in different velocity spectrums; e.g. 77 grain loads running around 2,650 fps compared to 55 grain loads running around 3,250 fps.

For comparison (and to give you an idea of how good the CV is for this factory loaded MK262 Mod 1 ammunition) the mil-spec for M193 allows for a coefficient of variation of approximately 1.2%, while one of my best 77 grain OTM hand-loads, with a muzzle velocity of 2639 PFS and a standard deviation of 4 FPS, has a coefficient of variation of 0.15%.





stnadard_deviation_of_4_fps_01-1342455.jpg





Accuracy

The specification for the accuracy/precision portion of the lot-acceptance-testing of MK262 calls for multiple 10shot groups to be fired from machine-rested, heavy test barrels. I conducted an accuracy (technically, precision) evaluation of the first-run MK262 Mod 1 ammunition following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any Group Reduction Techniques (e.g. fliers, target movement, Butterfly Shots).

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Also, a control group was fired from the test-rifle used in the evaluation using match-grade, hand-loaded ammunition; in order to demonstrate the capability of the barrel. Pictures of shot-groups are posted for documentation.

All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrel used in the evaluation was free-floated. The free-float handguards of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold VARI-X III set at 25X magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the top of the free-float hand-guard. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.





colt_with_pri_handguard_in_benchrest_001-1470442.jpg





The Wind Probe.

wind_probe_2016_01_framedb-1342522.jpg





The test vehicle for this evaluation was one of my semi-automatic precision AR-15s with a 20” stainless-steel Lothar Walther barrel. The barrel has a 223 Wylde chamber with a 1:8” twist.




lothar_walther_barrel_21_resized-1326537.jpg





lothar_barrel_crown_02_resized-1297385-1342445.jpg





lothar_walther_barrel_free_floated_05-12-1342446.jpg





Prior to firing the MK262 ammunition, I fired a 10-shot control group using match-grade hand-loads topped with the Sierra 77 grain MatchKing. That group had an extreme spread of 0.69”.




lothar_walther_control_load_01_measured-1342444.jpg





Three 10-shot groups of the MK262 Mod 1 were fired in a row with the resulting extreme spreads (from smallest to largest):

0.96”

1.12”

1.21”


for a 10-shot group average extreme spread of 1.10”. The three 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius for the 30-shot composite group was 0.33”.



The smallest 10-shot group.


black_hills_mk262_mod_1_best_group_02-1342440.jpg





The 30-shot composite group.

mk262_composite_group_02-1342450.jpg







molon_signature_005-1357735.jpg




….
 

Molon

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Full Member
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Feb 26, 2020
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Black Hills 5.56mm 77 Grain Tipped MatchKing Ammunition



black_hills_box_01_resized_with_77_tippe-1336385.jpg





The Black Hills 5.56mm 77 grain Tipped MatchKing ammunition is loaded with the same Sierra 77 grain Tipped MatchKing projectile that is available as a reloading component (#7177), with the addition of a cannelure. The Black Hills ammunition was actually brought to market before the reloading component was.



77_tipped_matchkings_box_02_resized_-1336380.jpg




The 77 grain Tipped MatchKing is the longest bullet (that I’m aware of) that is currently being loaded by a major manufacturer to magazine length for the 5.56mm cartridge.



long_bullets_15_b_resized-1336625.jpg




With a nominal length of 1.070”, the 77 grain Tipped MatchKing is 0.335” longer than a 55 grain FMJ bullet and 0.085” longer than the standard Sierra 77 grain MatchKing.



77_tipped_matchking_comparison_bullets_0-1336379.jpg




Not only is the bullet itself long, but the ogive section of the 77 grain Tipped MatchKing is also extremely long for a bullet loaded to magazine length in the 5.56mm cartridge; so much so, that the grooves of the cannelure extend into the ogive of the bullet, as evidenced by the “arrow head” shaped cannelure grooves.



77_grain_tipped_matchking_02-1336376.jpg





77_tipped_matchking_cannelure_grooves_01-1336378.jpg





77_grain_tipped_matchking_on_granite_blo-1336377.jpg





The Black Hills 77 grain Tipped MatchKing ammunition is loaded in 5.56mm WCC brass that has the annealing iris still visible. The primer pockets are crimped and sealed. The case-mouth is crimped but has no sealant. The load is charged with “ball powder.”



black_hills_77_tmk_cartridge_02_resized-1336383.jpg




black_hills_77_tmk_powder_resized_b-1336624.jpg





Velocity


I chronographed the Black Hills 77 grain Tipped MatchKing ammunition from a semi-automatic AR-15 with a chrome-lined, NATO chambered 20” Colt M16A2 barrel with a 1:7” twist.



Colt_20_inch_A2_barrel_02_border-1336386.jpg




Chronographing was conducted using an Oehler 35-P chronograph with “proof screen” technology. The Oehler 35P chronograph is actually two chronographs in one package that takes two separate chronograph readings for each shot and then utilizes its onboard computer to analyze the data to determine if there is any statistically significant difference between the two readings. If there is a statistically significant difference in the readings, the chronograph “flags” the shot to let you know that the data is invalid. There was no invalid data flagged during this testing.

The velocities stated below are the muzzle velocities as calculated from the instrumental velocities using Oehler’s Ballistic Explorer software program. The strings of fire consisted of 10 rounds over the chronograph.




oehler_chronograph_32-1336391.jpg





oehler_computer_02-1336390.jpg





Each round was single-loaded and cycled into the chamber from a magazine fitted with a single-load follower. The bolt locked-back after each shot allowing the chamber to cool in between each shot. This technique was used to mitigate the possible influence of “chamber-soak” on velocity data. Each new shot was fired in a consistent manner after hitting the bolt release. Atmospheric conditions were monitored and recorded using a Kestrel 4000 Pocket Weather Tracker.



kestrel_4000_21-1336387.jpg




Atmospheric conditions

Temperature: 72 degrees F
Humidity: 44%
Barometric pressure: 29.64 inches of Hg
Elevation: 950 feet above sea level

The muzzle velocity for the 10-shot string of the Black Hills 77 grain Tipped MatchKing ammunition fired from the 20” Colt barrel was 2808 FPS with a standard deviation of 14 FPS and a coefficient of variation of 0.50%.

For those of you who might not be familiar with the coefficient of variation (CV), it is the standard deviation, divided by the mean (average) muzzle velocity and then multiplied by 100 and expressed as a percentage. It allows for the comparison of the uniformity of velocity between loads in different velocity spectrums; e.g. 77 grain loads running around 2,650 fps compared to 55 grain loads running around 3,250 fps.

For comparison, the mil-spec for M193 allows for a coefficient of variation of approximately 1.2%, while one of my best 77 grain OTM hand-loads, with a muzzle velocity of 2639 PFS and a standard deviation of 4 FPS, has a coefficient of variation of 0.15%
.



stnadard_deviation_of_4_fps_01-1336393.jpg




Accuracy


I conducted an accuracy (technically, precision) evaluation of the Black Hills 77 grain Tipped MatchKing ammunition following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group-reduction techniques (e.g. fliers, target movement, Butterfly Shots).

The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Also, a control group was fired from the test-rifle used in the evaluation using match-grade, hand-loaded ammunition; in order to demonstrate the capability of the barrel. Pictures of shot-groups are posted for documentation.

All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrel used in the evaluation was free-floated. The free-float handguards of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold VARI-X III set at 25x magnification and adjusted to be parallax-free at 100 yards. A mirage shade was attached to the top of the free-float hand-guard. Wind conditions on the shooting range were continuously monitored using a Wind Probe. The set-up was very similar to that pictured below.





benchrest_krieger_rifle_02_JPG-1287996-1336381.jpg





The Wind Probe.

wind_probe_25_resized-1336395.jpg





The test vehicle for this accuracy evaluation was one of my semi-automatic precision AR-15s with a 20” stainless-steel Lothar-Walther barrel. The barrel has a 223 Wylde chamber with a 1.8” twist. Prior to firing the Black Hills 77 grain Tipped MatchKing, I fired a 10-shot control group using match-grade hand-loads topped with the Sierra 77 grain Tipped MatchKing (without a canelure). That group had an extreme spread of 0.68”.




lothar_walther_barrel_21_resized-1336364.jpg





lothar_barrel_crown_02_resized-1297385-1336365.jpg





lothar_walther_barrel_free_floated_05-12-1336366.jpg





The control group . . .

sierra77_grain__tipped_mk_handload_02b_r-1336392.jpg




Three 10-shot groups of the Black Hills 77 grain Tipped MatchKings ammunition were fired in a row with the resulting extreme spreads:


1.26”
1.14”
1.37”



for a 10-shot group average extreme spread of 1.26”. The three 10-shot groups were over-layed on each other using RSI Shooting Lab to form a 30-shot composite group. The mean radius for the 30-shot composite group was 0.41”.



The smallest 10-shot group . . .

black_hills_556mm_77_TMK_measured_10_sho-1336384.jpg





The 30-shot composite group . . .

black_hills_77_tmk_30_shot_composite_gro-1336382.jpg






MK262 Comparison

The table below compares the test results from this article to my previously obtained test data for Black Hills MK262 Mod 1 ammunition, which is loaded with the standard Sierra 77 grain MatchKing (with a cannelure.)



mk262_vs_77_tipped_matchking_table_02_re-1336389.jpg




A.E.S = average extreme spread for three 10-shot groups at 100 yards

M.R. = mean radius for the 30-shot composite group

M.V. = muzzle velocity

S.D. = standard deviation of muzzle velocity

C.V. = coefficient of variation of muzzle velocity



 

clcustom1911

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  • Oct 23, 2017
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    Black Hills 223 Remington 75 Grain Match HP Ammunition

    Blue Box versus Red Box





    black_hills_boxes_02_resized_darker_bord-1895277.jpg





    The difference between Black Hills’ red box and blue box ammunition lies primarily with the brass case. Red box ammunition is newly manufactured using virgin brass. Blue box ammunition is referred to as “remanufactured” because is uses once fired brass that has been resized. This enables Black Hills to sell the blue box ammunition at a reduced price compared to their red box ammunition.


    Black Hills’ 75 grain Match HP (hollow point) ammunition is loaded with Hornady’s 75 grain BTHP Match bullet with a cannelure (commonly referred to as the “T1C”) and both the red box and blue box loads have a crimp at the case mouth. Both loads are charged with “ball powder.” The nominal OAL for the red box cartridges ran approximately 2.245” and for the blue box cartridges it was closer to 2.250”.






    t1_t2_comparision_03-2254290.jpg






    The brass cases used in the red box ammo have sealed primers and the headstamp of most lots of this load read “BHA 223 MATCH.” These virgin cases have a nominal length of 1.755”.

    The brass cases used in the blue box load tend to be a mix of once fired Lake City and Winchester brass. The military primer crimps has been removed by the reaming method. The blue box loads do not have sealed primers.

    Black Hills does not perform a “trim to length” operation on the resized cases used in the blue box ammunition. As a result, many of the cases are longer than the SAAMI recommended maximum length of 1.760”. Several of the cases that I measured had a length of 1.775”. This could potentially cause problems in a barrel with a minimum length chamber, though no malfunctions of any kind were experienced during the testing of this ammunition. (Using a Sinclair chamber length gauge, I determined the chambers of my Colt barrels have a length of 1.780”.)

    Both loads were chronographed using four different length barrels. All of the Colt barrels used in testing have a NATO chamber and a 1:7” twist. The 24” Krieger barrel has a 5.56 Match chamber and has a twist rate of 1:7.7”. On their web-site, Black Hills advertises a muzzle velocity of 2,750 fps for these loads, but they do not state the barrel length associated with this velocity, though the industry standard calls for a 24” barrel.

    Chronographing was conducted using an Oehler 35-P chronograph with “proof screen” technology. The Oehler 35P chronograph is actually two chronographs in one package that takes two separate chronograph readings for each shot and then has its onboard computer analyze the data to determine if there is any statistically significant difference between the two readings. If there is a statistically significant difference in the readings, the chronograph “flags” the shot to let you know that the data is invalid. There was no invalid data flagged during this testing.


    The velocity stated below is the muzzle velocity as calculated from the instrumental velocity using Oehler’s Ballistic Explorer software program. The string of fire consisted of 10 rounds over the chronograph.


    Each round was single-loaded and cycled into the chamber from a magazine fitted with a single-load follower. The bolt locked-back after each shot allowing the chamber to cool in between each shot. This technique was used to mitigate the possible influence of “chamber-soak” on velocity data. Each new shot was fired in a consistent manner after hitting the bolt release. Atmospheric conditions were monitored and recorded using a Kestrel 4000 Pocket Weather Tracker.


    Atmospheric conditions

    Average temperature- 80 degrees F
    Humidity - 48%
    Barometric pressure – 29.04
    Elevation- 960 feet above sea level






    black_hills_75_mhp_barrel_comparison_of_-2254513.jpg





    While chronographing the Black Hills loads through the 24” Krieger barrel, I also chronographed three of Hornady’s SAAMI pressure, 75 grain loads that use the T1C bullet for comparison.




    black_hills_and_hornday_velocity_compari-2254516.jpg





    For additional comparison, I also fired the Black Hills loads side-by-side with some of the Hornady 75 grain SAAMI pressure loads from the 20” Colt A2 barrel.



    Colt_20_inch_muzzle_velocities_03-2254521.jpg






    100 yard Accuracy Evaluation of Black Hills 75 grain MHP

    Red Box versus Blue Box





    As previously discussed in this thread, the primary difference between Black Hills' red box and blue box ammunition lies with the brass case. Red box ammunition uses virgin brass, while blue box ammunition uses once fired brass that has been resized.

    The test-vehicle for this accuracy evaluation was a semi-automatic AR-15 with a 24” stainless-steel Kreiger VarMatch barrel, with a 1:7.7” twist, installed on a LaRue Tactical Stealth upper receiver.

    I conducted an accuracy (technically, precision) evaluation of the Black Hills 75 grain Match HP ammunition following my usual protocol. This accuracy evaluation used statistically significant shot-group sizes and every single shot in a fired group was included in the measurements. There was absolutely no use of any group-reduction techniques (e.g. fliers, target movement, Butterfly Shots).

    The shooting set-up will be described in detail below. As many of the significant variables as was practicable were controlled for. Also, a control group was fired from the test-rifle used in the evaluation using match-grade, hand-loaded ammunition; in order to demonstrate the capability of the barrel.


    All shooting was conducted from a concrete bench-rest from a distance of 100 yards (confirmed with a laser rangefinder.) The barrel used in the evaluation was free-floated. The free-float handguards of the rifle rested in a Sinclair Windage Benchrest, while the stock of the rifle rested in a Protektor bunny-ear rear bag. Sighting was accomplished via a Leupold Competition Series Scope which was adjusted to be parallax-free at 100 yards. A mirage shield was used. Wind conditions on the shooting range were continuously monitored using a Wind Probe.





    Control Groups


    Prior to testing the Black Hills ammunition, I obtained three 10-shot groups of a control load consisting of hand-loaded Sierra 55 grain BlitzKings (at a distance of 100 yards of course.) Those three groups had extreme spreads of:


    0.547”

    0.57”

    0.69”


    for an average extreme spread of 0.602”. The three 10-shot groups were overlayed on each using RSI Shooting Lab to obtain a 30-shot composite group that had a mean radius of 0.19”.




    Red Box



    Following the same procedures used with the control load, three 10-shot groups of the Black Hills red box 75 grain MHP fired from 100 yards were obtained. Their extreme spreads measured:


    0.96”

    1.00”

    1.04”


    for an average extreme spread of 1.00”. As with the control load, the three 10-shot groups from the red box ammunition were over-layed on each other to obtain a 30-shot composite group with a mean radius of 0.32”.






    Blue Box


    In the same manner as above, three 10-shot groups of the blue box 75 grain MHP were obtained from 100 yards with extreme spreads of:


    1.11”

    1.16”

    1.16”


    for an average extreme spread of 1.14”. Those three 10-shot groups overlayed on each other had a mean radius of 0.37”. Here are the 30-shot composite groups side-by-side for comparison.




    black_hills_75_mhp_composite_comparisons-2254525.jpg






    Lastly, for any Internet Commandos in our viewing audience, I fired a 3-shot group of the red box 75 grain MHP from 100 yards. That group measured 0.276”.
    icon_smile_big.gif





    3_shot_group_of_red_box_75_mhp_02-2254530.jpg








    molon_signature_005-1357735.jpg


    ..
    Excellent post as usual. Only one thing was missing:

    The doggie with the wind probe 😁
     
    Last edited:

    SBRSarge

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    Jul 9, 2019
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    Molon,

    I enjoy your posts and appreciate the time, effort and $$ you spend to glean the data and give such great detail. The historical info on the rounds is also enjoyed.

    And yes, the pups are an integral part of the reports!
     
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    Im2bent

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    The level of effort and detail you put into these posts is simply staggering. Thank you they are truly appreciated.