British SS109 5.56mm Ammunition: Cartridge, Caliber 5.56mm, Ball, L2A2 (United Kingdom)
Under STANAG 4172 (standardization agreement)5.56x45mm NATO is the standard intermediate cartridge chambering for NATO forces. SS109 NATO (known as M855 in the United States) is the 62 grain cartridge with a copper jacket, lead core and steel penetrator. In theory, this allows interchangeability of cartridges between member states of the organization
I acquired surplus British L2A2 (SS109 equivalent) ammunition a few years ago. Sold by a a number of bargain vendors for a relatively low price point, this ammunition has been the source of a number of rumors and debates on the net. I decided to take a closer look at it.
My ammunition came in 20 round brown cardboard boxes in 20 round quantities. L2A2 is the SS109 equivalent, and it is produced by Radway Green. L2A2 ammunition is also available in 10 round stripper clips and linked in belts.
I pulled the bullet, powder and primers from a few cartridges.
Note the tar seal on the projectile. Also, note the bullet does not have a green painted tip like most other SS109/M855 you’ll encounter. The bullet is secured with the case crimped into the cannelure.
I sectioned a L2A2 projectile (below right) and a Winchester M855 projectile (below left) on a belt grinder. The grinder melted the lead, but it allowed removal of the steel penetrators and examination of the jacket. Note the location of the penetrators in the jacket, these would normally be further forward, the belt grinder dragged them toward that base of the projectile.
Jacket thickness on the sides of the penetrator was .022″ on both projectiles.
The M855 penetrator was .320″ long. The L2A2 penetrator was .268″ long. The M855 penetrator is 19% longer.
The brass cases are annealed and appear similar to Winchester M855. My cases weighed an average of 99.3 grains (The Winchester M855 case I weighed was 93.4 grains) indicating smaller case capacity.
The primer is brass colored with a green compound and secured with a crimp.
The 24.3 grains of extruded powder was in a compressed load. The load was so dense, I needed a paperclip to remove it from the case, simply tapping the case left almost all the powder in the case.
Uncle Sam bought a large quantity of L2A2 ammunition during the ammunition shortage a few years ago. This ammunition was designated for training use only in the M16 and M249, but not the M4. Apparently, potential problems from its operational use were such a concern, that in Preventive Maintenance Monthly; Nov2013, Issue 732, p35, “Don’t gamble with ammo was published” (see below).
I fired a few hundred round of L2A2 through my carbine equipped with a Daniel Defense mid-length barrel. Firing at 50 yards, groups were consistent with what I had expected.
Both 5-shot groups were fired prone, unsupported at 50 yards. The top group was fired with a 4MOA T1, the bottom with iron sights.
I measured the velocity (ft/sec) of a 32-round sample of L2A2 using a MagnetoSpeed barrel mounted ballistic chronograph.
Average velocities were about 100 ft/sec slower than I had recorded in the same barrel with Winchester M855 ammunition.
The ammunition was dirty, but functioned fine. I was using a mid length gas system, but a friend who runs a carbine length system, told me he didn’t have any problems either.
I haven’t seen it on sale for a while, but if you do, you may want to consider picking some up.