Special Report: Advances in Ammunition
By Christopher Rance
The Workhorse
For over two decades, U.S. Military snipers have relied on the 7.62x51mm NATO sniper cartridge, M118LR (long range), to engage point targets with accuracy at long range and with minimal risk of collateral damage. The M118LR was designed to replace the underperforming M118 “Special Ball” (SB) because the tolerances on the M118 SB were subpar, with the biggest complaint arising from fluctuating powder charges that lead to wide spreads of muzzle velocity. In 1993, the United States Marine Corps collaborated with Lake City on the design of the new M118LR cartridge. Sierra Bullets was brought into the mix, and they provided the USMC with prototypes of their new bullet, now known as the 175 Sierra MatchKing. The 175 Sierra MatchKing was a 175-grain bullet with a reverse drawn copper jacket, lead core and a 9-degree boat tail design. The M118LR utilized a Copper Alloy No. 260 brass case and a No. 43 Boxer-style primer.
The M118LR ammunition saw widespread use in combat, with the majority of combat operations taking place in desert type environments, such as Afghanistan and Iraq, where temperature variations in a 24-hour period could be +/- 60 degrees. Snipers using M118LR ammunition started to become aware of M118LR’s sensitivity to temperature change. All firearm powders burn at different rates depending on the temperature, which then affects the velocity of the bullet as it leaves the barrel. Another critical issue with the M118LR ammunition was the excessive muzzle flash that it gave off during low-light shooting scenarios. This was a hinderance to the concealment of the sniper, and it impaired night vision.
Improvements to Sniper Ammunition
Throughout the conflicts of Afghanistan and Iraq, accuracy inconsistencies were identified by snipers. The Navy Special Warfare Center (NSWC) was tasked to develop an improved version of the M118LR ammunition to address the temperature sensitively, muzzle flash and accuracy complaints that snipers were voicing to their command. The improved cartridge also needed to function in the new crop of semi-auto sniper rifles being employed by the various armed forces, such as the M110, MK11 and SCAR17H rifles. The NSWC tested over 20 different powder combinations as well as 15 different projectiles. The testing specifications required that the standard deviation for velocity could not exceed 15 fps (feet per second) in order to minimize vertical spread due to velocity differences, and the accuracy of a 10-round group had to fall within a 7-inch extreme spread at 600 yards and a 3.5-inch extreme spread at 300 yards. It was also desired that the bullet still be supersonic (1000+ fps) at 1000 yards. In addition, the performance had to be comparable from -25 degrees to +165 degrees Fahrenheit.
Ammunition manufacturer Black Hills was at the forefront of the M118LR AB39 PIP (Product Improvement Program) round. Elements of the U.S. Army Special Forces stationed at Fort Bragg inquired with Black Hills to improve its existing 7.62x51mm M118LR cartridge to address the M118LR temperature stability issue. Black Hills immediately began environmental testing and found the M118LR showed velocity spreads as much as 227 feet per second and pressure spreads as much as 1,8120 psi between 165 degrees and -25 degrees. Black Hills’ input to the Army and Navy resulted in the solicitation for the improved round that became the AB39. The new AB39-PIP M118LR’s primary improvement is that the cartridge is loaded with a propellant that is much more temperature-stable. With the new powder, the velocity difference between 165 degrees and -25 degrees is 21 fps, whereas the older M118LR varied at 227 fps. Calcium carbonate also was added to the powder which considerably reduced the muzzle flash of the new ammunition. U.S. Army Special Forces also specified requirements for uniformity between lots.
Precision Intermediate Caliber
In October 2017, U.S. Special Operations Command (SOCOM) comparison-tested the performance of M118LR, .260 Remington and 6.5 Creedmoor cartridges in SR-25, M110A1 and Mk 20 sniper rifles. SOCOM determined that 6.5 Creedmoor performed the best. The 6.5 Creedmoor doubled hit probability at 1000 meters, reduced wind drift by a third and had less recoil than the 7.62 NATO round. Because the two rounds (7.62 and 6.5 Creedmoor) have similar dimensions, the same magazines can be used, and a rifle can be converted with a barrel change. Replacement of the 7.62 NATO cartridge with the adopted 6.5 Creedmoor for special operations snipers’ semi-automatic rifles is planned for early 2019. In response to SOCOM’s adoption, the Department of Homeland Security also decided to adopt the round.
The 6.5mm Creedmoor, designated 6.5 Creedmoor by SAAMI, is a centerfire rifle cartridge introduced by Hornady in 2007 as a modification of the .30 TC, which was based on the .308 Winchester. The 6.5 Creedmoor was designed specifically for long-range target shooting. Bullet for bullet, the 6.5mm Creedmoor achieves a slower muzzle velocity than longer cartridges such as the 6.5-284 Norma or magnum cartridges such as the 6.5mm Remington Magnum. However, due to its 2.825-inch (71.8mm) overall length, the 6.5mm Creedmoor is capable of being chambered in short-action bolt-action rifles and AR-10 semi-automatic rifles.
Increasing Lethality
The sniper applies field craft and camouflage to move into concealed positions that allow him the highest probability for delivering accurate fire onto a target. The adoption of the 6.5 Creedmoor over the M118LR NATO 7.62 round does just that; increases hit probability onto targets of opportunity. The 6.5 Creedmoor carries a higher ballistic coefficient than the 175 grain Sierra MatchKing, and the muzzle velocity for the 130 gr. 6.5 Creedmoor projectiles is almost 200 fps faster than the 175 SMK, yet has the same remaining energy at 1000 meters.
QUANTUM AMMUNITION, LLC
INCEPTOR® 7.62x39 and 223 REM Sport Utility Ammo
Inceptor® 7.62x39 and 223 REM Sport Utility Ammo features patented Short-Range Rifle (SRR™) bullet technology, injection-molding and polymer-copper materials. These offerings give AK and MSR enthusiasts a lead-free, range-compliant load. The unmatched frangibility of the SRR bullets allows users to shoot hardened steel at distances measured in feet, not yards.
7.62x39 SRR™
Order Code: 762X39SRR-20
Caliber: 7.62x39 SRR™
Projectile Weight: 90gr
Bullet Core: Polymer-copper
Average Muzzle Velocity: 2810 fps
Kinetic Energy: 1578 ft/lbs
Case construction: Standard brass
inceptorammo.com
223 Rem SRR™
223 20 Cartridges: 223SRR-20
223 50 Cartridges: 223SRR-50
223 500 can: 223SRRCAN
Caliber: 223 Rem SRR™
Projectile Weight: 35gr
Bullet Core: Polymer-copper
Average Muzzle Velocity: 3810 fps
Kinetic Energy: 1128 ft/lbs
Case construction: Standard brass
inceptorammo.com
QUANTUM AMMUNITION, LLC
9mm ARX®
Featuring the revolutionary ARX® projectile, Inceptor® 9mm Auto Preferred Defense™ performs much differently than other defense options. The lead-free, non-expanding ARX bullet penetrates most intermediate barriers without deformation and consistently achieves its terminal effect in soft targets.
Order Code: 9ARXBRLUG-65-25
Caliber: 9mm ARX™
Projectile Weight: 65gr
Ballistic Coefficient: .053
Bullet Core: Polymer-copper
Average Muzzle Velocity: 1650 fps
Kinetic Energy: 393 ft / lbs
Case construction: Standard brass
inceptorammo.com
FEDERAL PREMIUM
Hydra-Shok® Deep™
Federal Premium® Hydra-Shok® has proven itself for self-defense since 1989. Hydra-Shok® Deep™ builds off the time-tested platform with design improvements that better meet modern performance measurements. The bullet features a more robust center post and a core design that provides as much as 50 percent deeper penetration than original Hydra-Shok and competitor loads.
Features include:
- Penetrates 15 inches in bare ballistics gel—the optimal depth according to FBI standards
- 50-percent deeper penetration than original Hydra-Shok®
- 70-percent improvement in FBI protocol score
- Iconic center post design has been improved for better, more consistent expansion through standard barriers
- Consistent, specially formulated propellant
- Extremely reliable Federal® primer
Order Code: P9HSD1
Caliber: 9mm Luger
Projectile Type: Hydra-Shok JHP
Projectile Weight: 135gr
Ballistic Coefficient: 0.18
Bullet Core: Polymer-copper
Average Muzzle Velocity: 1060 fps
Kinetic Energy: 337 ft / lbs
Effective Range: 25yds to 100yds
federalpremium.com
FEDERAL PREMIUM
EDGE TLR™
Hunting at long range requires an extremely accurate bullet that still expands, holds together and penetrates deep. That’s why Federal Premium® has developed the Edge TLR™. Unlike other so-called long-range projectiles that can fail to perform on impact at lower velocities, the Edge TLR uses the exclusive Slipstream™ polymer tip to initiate expansion at long range. At close range, the bullet’s copper shank and bonded lead core retain weight for consistent, lethal penetration. Its long, sleek profile offers an extremely high ballistic coefficient and AccuChannel™ groove technology improves accuracy and reduces drag. The Edge TLR comes in four different calibers: 308 Win., 30-06 Springfield, 300 Win. Magnum and 300 Win. Short Magnum.
Order Code: P308ETLR175 (see website for other calibers and specs)
Caliber: 308 Win.
Projectile Type: Edge TLR
Projectile Weight: 175gr
Ballistic Coefficient: 0.536
Bullet Jacket: Copper
Bullet Core: Bonded lead core
Average Muzzle Velocity: 2600 fps
Kinetic Energy: 2627 ft / lbs
Effective Range: 50yds to 300yds
federalpremium.com
AGUILA AMMUNITION
Hollow Point Ammunition
Aguila Ammunition is excited to announce the return of hollow point ammunition to their centerfire product line. The company will launch the 9mm 117 grain initially with additional calibers to follow. The addition of the hollow point line means additional production capacity and a new manufacturing facility in Conroe, Texas.
Order Code (SKU): 1E092112
Caliber: 9mm
Accuracy: Average maximum 2.50
Projectile Type: JHP
Projectile Weight: 117.0 +/- 1.0 grain
Bullet Jacket: 20 +/- 0.5 grain
Bullet Core: 97 +/- 0.5 grain
Average Muzzle Velocity: 1150 +/- 45
Average Chamber Pressure: 34000
Effective Range: 27yds
Case construction: Brass strip
Primer Specification: 149
aguilaammo.com
This article first appeared in Small Arms Review V22N7 (August 2018) |
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