There is much confusion about the effects of these short barrels on velocity. It makes sense that a shorter barrel will produce lower velocity, but how much less? Since the Army rolled out the 14.5 inch barrelled M-4 in 1992, there have been a lot of people shooting shorter barrels. The SEALs developed the Mk18 with a 10.3 inch barrel and many military and law enforcement units have gone short. AR pistols have brought shorter barrels to the common man.

Over the last year or so, Eagle_19er posting on AR15.com has gathered forty-one different factory loads and tested 10 rounds of each in a 10.5″, 11.5″, 12.5″ and 14.5″ barrels to establish a baseline velocities. They run the gamut from 55gr Wolf Polyformance steel case to a few flavors of heavy OTM loads.

It’s by no means an exhaustive list of everything available in 5.56, but these loads cover many of the popular “off the shelf” (and a few more obscure) loads that many of us shoot at the range and/or depend on for self defense, hunting or duty.

You can see all of Eagle_19er’s work on AR15.com:  Suppressed 5.56 SBR Velocity Tests–41 Factory Loads from 10.5″, 11.5″, 12.5″ & 14.5″ ALL DONE

Guns used:

  • 10.5″ Noveske SwitchBlock with SilencerCo Omega suppressor
  • 11.5″ Faxon “Big Gunner” (Mid Gas) with SilencerCo Omega suppressor.
  • 12.5″ BCM Standard (Carbine gas) with SilencerCo Omega suppressor.
  • 14.5″ BCH BFH “Barrel – Hammer Forged” (Mid Gas) with SilencerCo Omega suppressor.

Ammo:

  • Speed Gold Dot 55 Grain Bonded
  • Speer Gold Dot 64 Grain Bonded
  • Speed God Dot 75 Grain Bonded
  • Barnes 55 Grain TSX-FB
  • Barnes 62 Grain TSX-BT
  • Barnes 70 Grain TSX-BT
  • Federal Fusion MSR 62 Grain Bonded
  • Black Hills 77 Grain Sierra TMK
  • Black Hills 77 Grain OTM
  • Australian Outback 55 Grain Blitzking
  • Australian Outback 69 Grain Matchking
  • Federal 69 Grain Matchking
  • Remington 55 Grain PSP
  • Fiocchi 55 Grain Soft Point
  • PPU 75 Grain HBPT Match
  • Hornady Black 75 Grain BTHP
  • IMI 77 Grain OEM LR Mod 1
  • IMI M193
  • PPU M193
  • PMG XTAC XP193
  • Winchester 5.56 55 Grain FMJ (Q3131)
  • Federal XM193
  • Federal .223 FMJ 55 Grain (AE223J)
  • PMC Bronze 55 Grain
  • Wolf Gold 55 Grain
  • MEN M193
  • Norma Tac 223 55 Grain
  • Wolf Polyformance 55 Grain (Steel Cased)
  • Hornady Steel (Steel Cased)
  • Silver Bear 62 Grain SP (Steel Cased)
  • Tula 75 Grain HP (Steel Cased)

Complete tables show the velocity, extreme spread, SD, and the actual shot string data for each barrel length.