Estimate chamber pressure and muzzle velocity for the 5.56x45mm NATO with the free,
in-browser MyLoads internal ballistics simulator. The figures below are illustrative
estimates from a physics model — not a recommended load. Always cross-check a current
published loading manual.
5.56x45mm NATO reference
Maximum average pressure (MAP)
62,350 psi
Nominal case capacity
30.6 gr H₂O
Groove / bullet diameter
0.224 in (5.69 mm)
Example simulation illustrative
Bullet
Hornady 0.224 73 gr ELD Match
Powder
Hodgdon CFE 223
Charge
22.2 gr
Barrel
20 in
Muzzle velocity
2,502 fps
Peak chamber pressure (interval, ±10% burn rate)
29,912 – 38,814 – 48,970 psi
nominal is 62% MAP (62,350 psi)
The simulator isn't optimized for this cartridge yet and may read pressure high or low.
Illustrative example — every figure is an estimate; always confirm your load against a current published manual before loading.
Popular 5.56x45mm NATO powders
Powders and bullets handloaders commonly use for the 5.56x45mm NATO, drawn from public discussion and listed most common first. They appear as the Popular group in the calculator's pickers. This is not a load recommendation — always check your load against a current published manual.
Hodgdon Varget
Hodgdon CFE 223
Hodgdon H335
Ramshot TAC
Winchester W748
Hodgdon BL-C(2)
Accurate A-2230
Alliant RL-15
Hodgdon H4895
Vihtavuori N140
IMR 8208 XBR
Hodgdon H322
Popular 5.56x45mm NATO bullets
Hornady 0.224 55 gr FMJ-BT W/C
Hornady 0.224 55 gr V-MAX
Nosler Ballistic Tip Varmint 22 Cal 55 gr Spitzer (Orange Tip)
Hornady 0.224 40 gr V-MAX
Sierra 22 Caliber (.224) 40 gr BlitzKing
Speer TNT Green .224 50 gr
Sierra 22 Caliber (.224) 63 gr SMP Varminter
Berry's Full Metal Jacket Boat Tail .224 62 gr
Barnes .224 62 gr TTSX BT
Sierra 22 Caliber (.224) 69 gr HPBT MatchKing
Nosler Custom Competition 22 Cal 69 gr HPBT
Hornady 0.224 75 gr BTHP Match
Berger 22 Cal 73 gr BT Target
Sierra 22 Caliber (.224) 77 gr HPBT MatchKing
Use MyLoads as a 5.56x45mm NATO velocity and pressure calculator: it estimates
muzzle velocity, muzzle energy and the full chamber-pressure curve for your own powder,
charge and barrel length, compared against the reference facts above.