And now for something a little different. I’ve shown you the headstamps and bullets used in the U.S. National Match ammunition, but now we’ll go inside to see the guts.
NM powders used over the years were very similar in appearance, except for a few that had a distinctive look. To make things worse, this is going to take up a big part of your flat-screen monitor, so try not to get too bored.
When the first National Match ammunition was manufactured by Frankford Arsenal , the standard service powder was single-base DuPont Military Rifle (MR) #20 which the government used in a non-canister grade called Pyro DG. It was used in all NM ammunition until 1920. With a kernel size of .030" x .078" it was a very plain-vanilla looking powder.
The 1920s ushered in an era of experimentation with both bullets (as we saw earlier) and powders as well. The 1920 NM powder was Improved Military Rifle (IMR) # 17 ½. With a kernel size very much like Pyro DG, .030" x .080", the “½" in the designation indicates the incorporation of tin which helped to lessen bore fouling. In 1921, IMR 1076 was used. Kernel size was .031" x .085". Instead of tin in the powder, the 1921 ammunition used tin-plated bullets to control fouling. It was popularly know as the “tin can” ammunition. In 1922, Frankford Arsenal abandoned the tin idea and switched to one of the Hercules double-base powders, HiVel #2, .030" x .087" in size. It was used until 1924.
1925 saw the return to the old reliable DuPont series of powders which were used almost exclusively for the next 71 years of NM ammunition production. 1925 - 1927 was loaded with IMR 1147, a short (.030" x .040") kerneled powder that is easy to recognize. Another short powder, IMR 1186 (.033" x .045") was used for two years, 1929 and 1930. In 1928 and from 1931 until 1940, the standard service powder, IMR 1185, was used. It is, essentially, IMR 1186 cut 11 to the inch, .032" x .085".
Post war match ammunition (1951 - 1956) consisted of selected lots of standard service grade Ball M2 or AP M2. It can be found loaded with either IMR 4895 or Western spherical WC 852, both of which were spec at the time. When production of NM ammunition resumed in 1957, the powder was the standard service powder that made its first appearance early in WW 2, IMR 4895. It was used in all Cal .30 Match M72, 7.62mm Match M118 (except as noted below), and 7.62mm Match M852. It changed little over the years, kernel size .035" x .060". In an attempt to use the service powder in NM ammunition, at least 7 lots of 7.62mm Match M118 were loaded with WC 846, another Western spherical.