We’ve undertaken the pain and expense of curating pressure-testing capability to develop our own Dagny Dagger loads, such capability is very rare outside of disinterested corporations, and Atlas Arms exists as an R&D non-profit firm for public benefit. In light of these, we would like to inform the public on this generally-unknown but critically-important aspect of ammunition specification by testing and publishing pressure data for commercially-available loads in conjunction with velocity. At this point, we are only able to test 9mm cartridges cased in NAS3 which fit a SAAMI-spec. chamber. That said, we are open to public testing requests and perhaps even custom load development.
Note: NAS3 cases produce very similar but slightly different ballistics than brass cases. SAAMI-spec. 9mmX19 (obsolete) chamber pressure is 35ksi, SAAMI-spec. 9mmX19 +P chamber pressure is 38.5ksi, and 9mmX19 “proof pressure” is 50-55ksi.
Pressure significantly less than SAAMI spec. accompanied by a much lower velocity than advertised. Underpowered on the whole, but just fine for close-range target shooting. Reasonable consistency.
Advertised velocity is accurate, though pressure is a bit low. Slightly underpowered but fine for close-range target shooting. Velocity is reasonably consistent while pressure is quite inconsistent, an apparent trend with ARM loads.
Average pressure is a little lower than SAMMI +P, though this is of little relevance as the max pressure is nearly 45ksi! Extreme inconsistency. Average velocity a bit lower than advertised. Note: inconsistency may be due in part to apparent loose crimp onto the exotic bullet which may allow the bullet to be jammed deeper into the case, increasing pressure with no velocity gain.
Advertised as “+P”, this load is far into the +P+ domain! Perhaps dangerously so. Very consistent percent-wise. Significantly higher-than-advertised velocity accompanied by absurd overpressure. Powder load reverse-engineered to 9.0gr.-9.1gr. Winchester Autocomp, CFE Pistol, or very similar-burning powder. This is a “textbook” extrapolation for a 50gr. +P 9mm powder load, so it is likely no one cared to test the pressure or optimize the cartridge before commercializing. This lack of due care also manifests in notably low velocity for such extreme overpressure. Still, before release of the Dagny Dagger, one might argue it to be the best defensive 9mm load on the market. Fast, light, and fragile.
Slightly high on pressure but spot-on true to advertised velocity. Velocity is slightly inconsistent and pressure moreso. This is a high-performer and it seems NovX is a good standard and example of good load development in forward-thinking configurations, separate from the debate to be had on the frangible injection-molded Cu/PA composite bullets.
Note: Slight overpressure here may be due in part or in whole to the bullets jamming deeper into cases to headspace in our SAAMI-spec. Universal Receiver (UR) barrel, which may increase pressure without significant velocity increase. Extremely rarely if at all are 9mm barrels chambered to SAAMI-spec., but rather cut to various deeper throat depths. Clearly NovX cartridges are spec'd for real pistol barrels, so this is the only NovX load which chambered well enough in our UR barrel for testing.