Commercial Pressure-Velocity Data

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.

Oak Island Ammunition 9mm 124 Grain FMJ
Manufacturer Data Source Date Barrel Length (in) Barrel Twist (in/r)
Oak Island Ammunition Atlas Arms  10/15/2019 4 10
Caliber Bullet Weight (gr) Bullet Type Load Case
9mm Luger 124 FMJ Ball Std. P NAS3
Sample Pressure (psi) Velocity (fps) Notes
1 33118 1026 --
2 33038 1006 --
3 31873 1000 Min Pressure, Min Velocity
4 32168 1015 --
5 33399 1016 --
6 33316 1024 --
7 32869 1022 --
8 34135 1028 Max Pressure, Max Velocity
9 33693 1025 --
10 32348 1008 --
Average 32996 1017 << SAAMI P, << Advertised V
Advertised/SAMMI Spec. 35000 1130
Standard Deviation 703 10
Spread 2263 28

 

 

 

 

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.

ARM 9mm Luger 124 Grain CuMJ-RN
Manufacturer Data Source Date Barrel Length (in) Barrel Twist (in/r)
American Reserve Munitions Atlas Arms  10/3/2019 4 10
Caliber Bullet Weight (gr) Bullet Type Load Case
9mm Luger 124 FMJ Ball Std. P NAS3
Sample Pressure (psi) Velocity (fps) Notes
1 33690 1065 Min Pressure, Min Velocity
2 34977 1079 --
3 34076 1074 --
4 35088 1084 Max Pressure
5 34205 1074 --
6 30606 1074 --
7 35051 1100 Max Velocity
8 35066 1085 --
9 34457 1096 --
10 33774 1077 --
Average 34099 1081 < SAAMI P, == Advertised V
Advertised/SAMMI Spec. 35000 1086
Standard Deviation 1342 11
Spread 4482 35

 

 

 

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.

ARM 9mm +P - G9
Manufacturer Data Source Date Barrel Length (in) Barrel Twist (in/r)
American Reserve Munitions Atlas Arms  10/10/2019 4 10
Caliber Bullet Weight (gr) Bullet Type Load Case
9mm Luger 80 Fluted Sol. Cu +P NAS3
Sample Pressure (psi) Velocity (fps) Notes
1 28915 1343 Min Pressure, Min Velocity
2 37872 1479 --
3 37314 1490 --
4 37717 1488 --
5 37210 1478 --
6 38291 1482 --
7 39410 1505 --
8 44808 1580 Max Pressure, Max Velocity
9 39811 1533 --
10 39405 1503 --
Average 38075 1488 < SAAMI P, < Advertised V
Advertised/SAMMI Spec. 38500 1525
Standard Deviation 3906 60 Very Poor Consistency
Spread 15893 237 Extreme Variation

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.

Liberty Civil Defense Ultra-Light "+P"
Manufacturer Data Source Date Barrel Length (in) Barrel Twist (in/r)
Liberty Ammunition Atlas Arms  2/16/2020 4 10
Caliber Bullet Weight (gr) Bullet Type Load Case
9mm Luger 50 Copper XHP +P NAS3
Sample Pressure (psi) Velocity (fps) Notes
1 45977 2137 Min Velocity
2 44700 2154 --
3 44447 2169 Min Pressure
4 46388 2179 --
5 47506 2180 Max Pressure, Max Velocity
6 45444 2166 --
7 46910 2162 --
8 46916 2159 --
9 46733 2149 --
10 45118 2156 --
Average 46014 2161        Dangerously High Pressure (>>+P)!,     > Advertised V
Advertised/SAMMI Spec. 38500 2000
Standard Deviation 1044 13 Consistent Velocity
Spread 3060 43 Wide Pressure Spread

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.

NovX 9mm Luger +P ARX
Manufacturer Data Source Date Barrel Length (in) Barrel Twist (in/r)
NovX Atlas Arms  10/18/2019 4 10
Caliber Bullet Weight (gr) Bullet Type Load Case
9mm Luger 65 Fluted Cu Comp. +P NAS3
Sample Pressure (psi) Velocity (fps) Notes
1 39835 1830 Max Velocity
2 39843 1787 --
3 38136 1818 Min Pressure
4 41577 1801 --
5 38999 1792 --
6 38704 1794 --
7 40567 1795 --
8 39612 1784 Min Velocity
9 39401 1789 --
10 41803 1793 Max Pressure
Average 39848 1798 > SAAMI P, == Advertised V
Advertised/SAMMI Spec. 38500 1800
Standard Deviation 1181 15
Spread 3667 46

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.