Nammo 5,56 BNT4


has someone a picture/drawing of a sectioned Nammo 5,56 BNT4 MKII (NM 255 M)?

Best regards and thanks


BNT4 HP Mk 2 is the Nammo designation for the Norwegian “Green” 5,56x45 NM255 round. I may have missed something, but I am not familiar with any “M” in the NM255 designation. BNT4 HP is the designation for the “old” NM229. The image covers both of them, sectioned by Reinhold Peschke. The difference between the NM229 and NM255 (BNT HP and BNT HP Mk 2) is mostly the slight boat tail on the NM255, to reduce barrel friction. There is also an other type of powder used. (Note: The “powder” on the sectioned cartridges is not powder, but some sort of inert material).
Both cartridges are totally lead-free, with a two-part core; hardened steel in the front and softer steel in the rear end.


1 Like

Dear Morten,

thank you very much for the explanation and the picture!!!

Best regards


I think the “M” is just a mistaken part of the wording “M/LADESKINNE” (on clips).
Means there should be no NM255M.

Here the plastic packing: