Wednesday, July 1, 2009

So, the Experiment is set...

Well actually, a start has been managed. James over at Handbasket made a statement that caused me to ask a question (actually more than one). He saw fit to address it (them) in a blog post and now my curiosity is even greater than before.

Today, I borrowed a decibel meter (Extech Instruments 407730) from work and will use it some time this weekend to see if a revolver (.44 magnum Super Blackhawk) is louder than an autoloader (.44 magnum Desert Eagle Mk VII). I chose these two because they are the only pair that I have that fits the design criteria of the experiment.

Design (intent)...
1. The firearms must be able to chamber and fire the same ammunition.
2. They must both be of similar size (e.g. medium frame or full size, etc).
3. The meter will be held in my left hand next to the grip and facing me.
4. Six (because the Ruger holds six) rounds will be fired in each firearm.
5. An average for each firearm will be calculated as well as a standard deviation for each population.

Also, the following are true...
a. This means that I will be shooting one-handed. -- So what.
b. The meter is multi-directional. -- It does not matter which way it is facing.
c. I chose this configuration to make the location of the meter firearm specific, not user specific. -- As in, my ears are probably farther away than some folks'.
d. I have not calibrated the meter. -- I am comparing one firearm immediately to another, it does not matter to me.

If anyone has anything to add, I will probably be at it Saturday and am open to suggestions on how to better the experiment. Also, engineer, not artist... so, the pictures will be amateurish at best.


  1. Great idea! I'll be fascinated to find out what the results are!

  2. Which sound meter do you have? I might borrow one from work also and do some similar tests. It might be interesting to compare .22 LR ammunition from an auto pistol and a revolver. I can do that. I could also compare .45 ACP from an M1911 pistol and my S&W 625 revolver.

    What I have done previously is measure peak decibel levels of typical handgun ammunition when fired from longer rifle-length barrels. This is of interest to me for the low noise, so that I can target shoot or dispatch garden varmints without disturbing the neighbors.
    Ordinary factory .38 Special target wadcutter ammo fired from a 6-inch target revolver is about 90dB when measured at 1 metre from the muzzle, ordinary 158-gr. LRN standard velocity about 95dB and 158-gr. +P about 100dB. Firing the same ammos from a 24 inch Marlin 1894 CBII lever action gives about a 10-12dB reduction in noise level, which is quite significant.

    A noise level of 80dB compares to firing standard velocity .22 LR from a typical sporting rifle such as a Ruger 10/.22. An efficient "can" or suppressor firing subsonic 9mm ammunition from a Mk.23Mod0 or HK MP5SD can produce noise levels down in the 72-75dB range, which compares to firing Eley Tenex from a long barreled .22 match rifle.

  3. Instrument is an Extech Instruments Model Number 407730 Sound Level Meter. The website for it is...

  4. And, from the when I hit the post button too quickly...

    ke4ksy: good and interesting stuff there...

  5. "the pictures will be amateurish at best."

    Gun in one hand, sound meter in the other, any pictures you manage to take will be, by their very nature, AWESOME. :P