7.9mm BESA primer crimps


During the WWII period the British used (at least) ring, 3-stab and no primer crimps on the 7.9mm BESA ammunition. I can understand the reasoning behind the crimps on the proof (K.44 Q.II) and the other special purpose ammo, but why have no crimps and ring crimps on the ball rounds?


Case hardness to suit the BESA was finalised in 1937-1938 by Kynoch so it’s not for that reason…but could it be that the “Caps out” syndrome had an effect on thought towards crimping primers from Bren gun sagas? The firing pins are of course the same half moon profile for the BESA as the Bren. A smaller primer of brass would be more resistant to the distortion than a .250 copper primer of .303 origin. SLEM rifle trials were a couple of years away by the official accounts so…where does that leave your excellent question?
Did Kynoch make WW2 contracts for China? What if they insisted on crimps for Bren ammo in 7.92?
Yours is a good point to bring up!


Indeed a very good question, Phil, one to which I do not know the answer!

Like you I have both crimped and uncrimped ball rounds, but I will go and check what dates/manufacturers they are and post details in a while. All ball rounds should have been ring crimped in British service, so I do not know the expalnation for the uncrimped ones.

The extra stab crimping on the Incendiary B Mark Iz is because the B.Iz was prone to feed prematures in the breech and it was an extra precaution, especially as the open breech was by the gunners ear! Many tank gunners took to hanging a sheet of sacking btween the Besa and their head, although I am not sure how much good that would have done! The BIz was only in service for a short time and was quickly replaced by the BIIz.

I will have a look also to see if there are any references to this in the SAC Minutes/O.B. Procs.

HB857 - Yes, Kynoch ammunition was sent to Chima in WW2, but it was all normal production BESA ammo. Picture shows crate label for Kynoch K44 GIIz tracer.



Phil - I have had a look through my BESA rounds and there seems little rhyme or reason to whether or not thay have ring crimped primers.

I have:
Ball rounds with and without crimps (including those you show)
Tracer with and without crimps
Incendiary all with either ring or stab crimps
AP all uncrimped
Proof with crimp.

I will try to find the manufacturing specification sheets and see if they say anything, but I will not be at the archives until mid January.

Have a Happy Christmas,


Tony – Thanks
Your list of types corresponds to what I have in my collection
Merry christmas