ID: .30-06 US made Berdan primed cases 1926-1927

Can anybody shed some light onto these 2 Berdan primed .30-06 cases?
And why two different primer sizes?
And what are the B11 and B30?

Headstamps are:
FA 26 B11
FA 27 B30



The following information is from HWS Vol. 1, pages 126-128.

During the 1920s Frankford Arsenal conducted extensive experimentation with various Berdan primers, primarily in an effort to develop noncorrosive (nonchlorate) priming mixtures. The Berdan type primers were used because it allowed larger amounts of priming compound to be used and provided more direct ignition.

Both headstamps shown above are listed in HWS, descriptions are as follows:

FA 26 B11- Cal. .30 case, T1-E1

0.25 inch diameter (11mm Vickers size), two-hole Berdan primer loaded with No. 11 noncorrosive primer mixture. B11 indicates a Berdan No. 11 primer mixture. The primer used was made of brass.

FA 27 B30- Cal. .30 case, T1-E2

0.21 inch diameter (Cal. .30), two-hole Berdan primer loaded with No. 30 noncorrosive primer mixture. The primer cups used were made of either monel or brass with circular primer crimp. The loaded cartridge using this case was referred to as Cal. .30 Ball Cartridge, T1.

While not stated in the text, I assume the “B30” portion of the headstamp indicates the primer type i.e. Berdan primer, 0.21 inch with No 30 primer mixture.


Brian, thanks a lot for doing all the digging!
Seems the experiments lead nowhere then.
Could these have been air force tests?


From the HWS pages listed above there is mention of work with the Garand primer actuated rifle and the brief use of noncorrosive primers with match ammunition (over pressure problems are noted) but no mention of the Army Air Corps.