This past weekend, I took some video while Damsel was shooting at the range. Apparent in the videos was the flash associated with firing. Also apparent, is the concussion and report. I did some research and found these interesting characteristics associated with Muzzle Blast:
Muzzle blast characteristics
The muzzle blast is often broken down into two components, an auditory component and a non-auditory component. The auditory component, the sound of the muzzle blast, is important because it can cause hearing loss or give away the gun’s position, while the non-auditory component, the overpressure wave, can cause damage to items near the blast.
Auditory
- Sound – The sound of a gunshot can be loud enough to produce hearing loss, and with big guns such as artillery, that danger can extend outwards a significant distance from the muzzle. Muzzle blasts can reach levels of 140 decibels, which can cause permanent hearing loss even with brief and infrequent exposure.
- Overpressure wave (concussion) – The overpressure wave from the muzzle blast of a firearm can contain a significant amount of energy; in artillery, the force of the muzzle blast can cause damage to surrounding structures and vehicles. Residual pressures at the muzzle can be a significant fraction of the peak chamber pressure, especially when slow burning powders or short barrels are used.
Image – Damsel firing (top) the Glock 30
and (bottom) Smith & Wesson 686
Non -auditory
- Muzzle glow – Muzzle glow is a reddish glow that is visible before the bullet leaves the barrel. Muzzle glow is created by superheated gases that have leaked past the projectile and have exited the barrel.
- Primary flashes – The primary flash is caused by propellant gases exiting the firearm behind the bullet. Although amongst the brightest of the flashes, the heat of the primary flash dissipates quickly and thus is no longer visible.
- Intermediate flashes – The intermediate flash is caused by shock waves created by the high speeds of the escaping gases and projectile, and appears as a reddish disc shape in front of the muzzle.
- Secondary flashes – Secondary flash appears farthest from the muzzle as a large white or yellow flame. Secondary flash is caused by the mixture of fuel-rich gases and oxygen in the atmosphere surrounding the muzzle.
- Sparks – Following the dissipation of the muzzle flash, partially unburnt powder or other heated materials can be ejected from the muzzle and appear as sparks.
Not apparent in the images above is the report and concussion. Both the .45 and .357 have a loud report and although the flash appears less intense in the .357, the concussion is significantly stronger than the .45.
Some fireballs I’ve had the joy of making.
Also, I specifically load my .357s to make a concussion blast that scares the dead. I call them my “Sound and Fury” loads. The sound gets confused for a .44 Magnum which makes me smile š
Awesome pix, Robb.
There weren’t any small children in the range, but one (extra-large) teenager walked over and stood behind us to see the show. Others outside the range came over to the windows to peer in at us.
One of these days, I need to try reloading. Sounds like it could be more fun than we’re having now.
Not very expensive to start if you’re willing to do a little extra work – e.g. a single stage or turret press. Progressive presses are $$$ but will churn out ammo like it’s going out of style.
Since I shoot 10mm, it was either get into reloading or get a second mortgage to pay for ammo.
Given the nature of my job, I usually compensate for both the auditory and the non-auditory traits of the muzzle blast. Tactically speaking, for the auditory, we position ourselves strategically in order to ābounceā the sound off of a nearby structure or terrain feature. The result of this being that, for the targetās friends, the sound will appear to originate from a direction other than where the round came from.
The non-auditory trait is compensated with a combination of the weapon design itself (flash suppressor, compensators, etc) and properly positioning ourselves to take a shot so the flash and sparks donāt give away our position. This takes care of the muzzle glow, the primary, the secondary flashes, and the sparks.
The exception to these is when we WANT to be seen, such as the case of using a shotgun at night due to the āflameā output.
In order to avoid hearing and concussion damage, we research and find out what the potential decibel output for the weapon system is, and then we compensate, either with standard earplugs or a combination of earplugs and shooting ear muffs. In order to reduce the toll of the concussion on our bodies as a whole, we utilize different firing positions such as sitting or prone in order to fire. Prone is obviously the preferred method for us due to the stability it provides, low silhouette, and lower exposure to the concussion.
While in the Air Force, I was NCOIC of the Security Police indoor fireing range at one point, and know for sure the effects of muzzle blast. I have lost 20 % of my hearing. Of course had I used the proper equipment all of the time maybe I could still hear. Ha. Proper gear is the same as read the manual. I hate to do both and will only do it when all else fails.
I appreciate comments from these expert shooters. There’s always something interesting to learn from the various perspectives you guys provide. We’re still learning even though we have been into shooting for years.
I was always curious why the .357 concussion was louder than the .45. I have shot and reloaded both rounds for years. I remember years ago I took a friend of mine (he is now a NYS Superior Ct judge) to shoot my duty weapon, a Colt Trooper .357. I loaded it with 5 of my issued S&W Police+ rounds (for some odd reason we were issued .357 revolvers but could only use .38 Special ammo) and 1 of my “special” .357 loads. He shot the first five under my direction and then I stepped back for the last round. Boom! After nearly crapping his pants, he said he thought it was the Second Coming. I am seriously looking at the new S&W .50 cal revolvers – just to say I own one. It would probably break my wrist.
Ha! Sneaking in a magnum round after the relatively docile .38 loads is a neat trick!
Damsel tried to hold up a .50 cal at the gun shop with one hand – she needed both hands to keep the barrel pointing downrange. We have yet to try out a .50. Maybe we can rent one at the range.