Good afternoon everyone and welcome back to TFB’s Silencer Saturday brought to you by Yankee Hill Machine, manufacturers of some of the most high-performing, yet affordable suppressors in today’s market. Last week we talked about Game Theory and Form 1 NFA Firearms. This week we take a glimpse into the past before NFA ever existed, one can only dream of such a utopia, and look at scans of an original Maxim Silencer catalog.
Maxim Silencer @ TFB:
Maxim Silencer Catalog And Instructions
We scanned an original Maxim Silencer catalog and instructions and there is a lot of information in just eight pages.
On the front of the Maxim Silencer catalog are some photos of rimfire pistols and rimfire rifles sporting Maxim 1923 silencers.
The second page of the Maxim Silencer catalog shows some centerfire rifles, a Springfield and Winchester both with Maxim 1921 silencers.
Below that image, Maxim explains how silencers work:
HOW THE SILENCER OPERATES
The Silencer checks the muzzle blast. Instead of the powder gases being liberated into the air instantaneously when the bullet emerges from the muzzle, they are caught by the Silencer, and allowed to escape gradually. This is accomplished by the SILENCING CHAMBERS, which are so constructed as to offer a very high resistance to a rapid flow of gas through them, but very little resistance to a slow flow of gas. The hole in the Silencer is much larger than the bullet and the latter does not touch anything in passing through, and consequently accuracy of flight and velocity are just the same with or
without the Silencer.
It is interesting the terminology used back in the 1920s. SILENCING CHAMBERS are what we would call baffles. I do have my doubts about the “accuracy of flight and velocity are the same”. Perhaps Hiram Maxim’s suppressors were that good back then? In comparison, we know modern-day suppressors can have a POI shift and/or an increase in velocity.
Next in the Maxim Silencer catalog, he explains the reduction of noise.
HOW MUCH IT REDUCES THE NOISE
The Silencer annuls almost all the noise of the gun report. On high power rifles it also reduces the recoil over two-thirds. The reason for this is that there is a very strong tendency for the Silencer to be blown off the end of the gun. This tendency amounts to a forward pull on the gun barrel. This forward pull counter-balances part of the backward kick.
The only noise the Silencer does not control is the noise made out in the air beyond the gun by a bullet in its flight. This noise is a “crack”‘ like the crack of a whip and not a “whistle or a “shriek”‘ as is commonly supposed. The noise is made by the same thing that causes the air to crack when a whiplash is snapped.
Hiram Maxim is describing the sonic boom the bullet makes breaking the sound barrier. Of course, the sound barrier won’t be broken until 20+ years later by Chuck Yeager.
This noise cannot be avoided when the bullet velocity exceeds 1,075 feet per second, no matter how quet we make the gun. .22 Short and .22 Long Rifle ammunition is below this, and flies quietly. .22 Long and .22 W. R. F. and all high power ammunition are above the critical velocity and usually give bullet flight noise.
I was curious how shooting enthusiasts and captains of the firearm industry calculated bullet velocity without chronographs. Turns out there were several ways such as using a ballistic pendulum or a wheel-style chronograph – something about two wheels spinning and you shoot through both discs and based on the speed of the spinning discs you measure the difference in position of the holes in the discs and you can calculate the velocity of the bullet. There may have been other ways as well but it was possible back then. Obviously, he does not know the term subsonic and supersonic with regard to bullet velocity but he clearly describes it in the Maxim Silencer catalog back in the 1920s. Also, we should now use the phrase “bullet flight noise” to describe the supersonic cracks of bullets from now on.
Shot cartridges up to .45 calibre work perfectly in the Silencer and make noiseless miniature trap shooting possible without disturbance or danger. On single shot target pistols it improves marksmanship to a surprising degree as it avoids nearly all recoil, or “flip”.
I am unsure how a .45 caliber shot cartridge can fit in the Model 1921 or 1923 silencer since they are for .30 cal and .22 cal respectively. Also, I would be concerned about the shot wreaking havoc on the “silencing chambers” aka baffles.
The Maxim Silencer will not operate on revolvers. No revolver can ever be silenced. If you stop the noise at the muzzle. it makes its escape at the gap between the cylinder and the barrel. Every revolver must have this gap.
I wonder if Maxim ever saw or heard of the Nagant revolver? For those of you not familiar with it, it has a unique gas sealing cylinder that closes the dreaded cylinder gap when the revolver is fired. It was in service since 1895. Granted it was mostly used by Russians but there is still a possibility he could have come across one and potentially could have suppressed one by the 1920s.
Next up in the Maxim Silencer catalog is the price list. According to an online inflation calculator, the Model 1923 silencer with the coupling and shims would cost $118 today. Just the .22 cal silencer with an assembling tool would cost $102.27 today. Not bad for a .22 rimfire can. If you wanted a centerfire .30 cal silencer it would only set you back a mere $165.20 today. That is rather cheap. What isn’t cheap is the tax stamp required by the NFA Act just over 10 years later. The $200 tax stamp back then would cost you $3,358 today.
The Maxim Silencer catalog even has instructions for taking a Maxim silencer apart and reassembling it with the assembling tool. There are 18 baffles in a Maxim silencer!
The Maxim Silencer catalog even has a handy measuring guide you can cut out to measure your barrel and choose the right size coupling. This is a shimmed threaded adapter rather than threading the actual barrel. Maxim does offer barrel threading but if you want to thread the barrel yourself, Maxim provides the thread pitch needed for his silencers. To my surprise, they are very close to modern day thread pitches. Below are the modern day thread pitches. Compare that to the catalog excerpt below.
- .22cal 1/2-28
- .40cal 9/16-24
- .30cal 5/8×24
- .45cal .578×28
The next two pages of the Maxim Silencer catalog are a list of notes regarding his silencers. Here are some excerpts I found interesting and amusing.
4. Sometimes a Silencer will be put on the gun crooked. By this, we mean that the hole in the Silencer will be out of line with the hole in the gun barrel. This obstructs the clear flight of the bullet. It causes inaccurate shooting or injury to the Silencer. When a Silencer is first attached to a gun it is wise to test its alignment by means of a straight rod which may be thrust down through the Silencer and the gun barrel. If this rod is straight and if it IS a fairly snug fit in the gun barrel, it will indicate at once whether the hole in the Silencer is in line with the hole in then barrel. The rod should pass through the Silencer without touching. If it does touch. the Coupling should be taken of and put on properly, or some other correction made. The gun will not shoot properly unless the bullet has a clear flight through the Silencer without touching.
What do you know? He is talking about bore alignment rods in the roaring 20s. I guess the simplest tricks are the best.
13. Do not blame the Silencer for not controlling ALL NOISES. All the Silencer can control is the report noise. It cannot silence bullet flight noise, nor the noise made by the impact of a bullet against a tree trunk or backstop, nor the mechanical noise made by the breech mechanism of an automatic rifle or target pistol. Frequently the Silencer is blamed for not controlling these noises, so that we have to mention it
I find it amusing that people complained about the noise of the action back in the 1920s. I said the same thing to Greg Latka of GSL in that his suppressors were too effective and made the noise from the action more obvious than I was accustomed to.
15. On high power rifles the Silencer alters the targeting on account of the added weight changing the vibration characteristics of the barrel. This can be provided for by adjusting the front or rear sight.
Hiram Maxim seems to be talking about barrel harmonics and the weight of the silencer will shift POI. This seems to contradict his earlier claim on page 2 that the “accuracy of flight and velocity are just the same with or without the silencer.”
The following section is the craziest thing I have read in the Maxim Silencer catalog.
HOW TO FIND IF YOUR SILENCER IS SILENCING.
In a single shot or repeating rifle there are two separate noises made when shooting a high power rifle.
- One is the noise made by the “REPORT” or that noise caused by the sudden liberation of the powder gases into the air.
- The other noise is that made by the BULLET’S FLIGHT.
The “Report Noise is practically enurely annulled by the Maxim Silencer. The Bullet Flight Noise is not affected by the Maxim Silencer, because it is produced out beyond the gun.
The noise which indicates the general location of a gun is the “Report” Noise. The Bullet Flight Noise does not give any indication of location, whether North, East, South or West.
It is, of course, true that a gun makes the same noise no matter in what direction it is pointed.
It is also a fact, although not so well known, that the bullet makes a sharp crack in its flight through the air if velocity exceeds a certain figure. This noise. is called “Bullet Flight Noise.” It occurs out in the air beyond the gun. It can only reach the ears of the shooter by reflecting back from some object. The ground, trees, or bulldings are such objects.
Ok hold up there Hiram, while sounds do bounce off objects, the “bullet flight noise” is a supersonic crack and propagates everywhere 360º.
One way to demonstrate the noise, and incidentally to prove whether the Silencer is working right, is to fire into a bag of soft earth or sand, holding the muzzle or the gun with Silencer within three or four inches of the bag. There is small opportunity for bullet flight noise to develop across this small distance, and the noise heard is principally that made by the impact of the bullet against the sand.
If the Silencer is working right, this noise should be a heavy “‘grunt.” After trying this, step back twenty-five feet and fire into the bag of sand. A sharp “crack” will be heard. This is BULLET FLIGHT NOISE. The gun report is the same whether held up close to the bag or not. If you doubt it, try it.
Another way to demonstrate is to go out into an open field clear from all objects like trees or buildings. First shoot the bare gun straight up into the air then also parallel with the ground. You will hear the report noise both times.
This sounds potentially dangerous and irresponsible. Do not try this at home.
Now put the Silencer on and repeat. When you shoot up into the air, you will hear only a “soft” noise. This is what is left of the report noise. There is no bullet flight noise heard, because there is nothing up in the air to reflect the noise back to your ears. The noise goes on and on and never returns.
That is not how any of this works. As mentioned above, supersonic cracks propagate 360º regardless of what direction you shoot the bullet. You will hear the crack. I wonder how much of Hiram’s hearing has been lost due to shooting unsuppressed while testing his silencer designs. I am sure his early attempts were not perfect which could increase his chances of hearing damage. So perhaps he is not hearing the supersonic crack as well as someone without hearing damage would?
Now shoot parallel with the ground. You hear a “crack.” If you shoot past separate trees or telegraph poles, you will hear the bullet as Shooting down a railroad track, past a long row of telegraph poles, sounds like a clatter.
Don’t try this either. Do not shoot down a railroad track.
Of course the gun makes the same noise whether pointing up or down, so the noise heard in this last test is bullet flight noise.
Bullet fight noise begins when the bullet velocity exceeds the velocity of sound. It is approximately 1,075 feet per second.
I was just about to question “how does he know the speed of sound?” and I found this according to Brittanica.com:
The earliest precise experimental value for the speed of sound, obtained at the Academy of Sciences in Paris in 1738, was 332 metres (1089) per second—incredibly close to the presently accepted value, considering the rudimentary nature of the measuring tools of the day.
So Hiram Maxim did know the speed of sound back in the 1920s.
If vou crowd any object through the air faster than this rate the air “breaks” something as the bow wave of a boat breaks when it is forced through the water faster than the water can get away from the bow. The tip of the whiplash “cracks” when you snap it vigorously enough to cause it to acquire a velocity in excess of 1,075 feet per second.
This is truly amazing. He is talking about the shockwaves generated off of tips of moving objects when they break the sound barrier. It was a German physicist, August Tophler, who is responsible for the conventional Schlieren system of observing changes in the density of air. He studied shockwaves and thus discovered super-sonic shockwaves back in the mid-1800s. The bow wave of a boat is a great analogy to mach angles off of bullets. Read more about shockwave shadows in this article. And here for DIY Schlieren.
Final Thoughts On The Maxim Catalog
The last page has a list of testimonials. They read like social media comments only with better grammar and a lot more politeness. I found the Maxim Silencer catalog fascinating. It surprised me how much of what is in the catalog is similar to modern silencer design. Of course, 18 baffles are a bit ridiculous, but the size and design has not changed much at all. What truly intrigued me was the description of the science behind silencers that we sort of take for granted as common knowledge. Hiram described things like supersonic crack (bullet flight noise) as well as POI shift due to barrel harmonics. He even mentions shockwaves off supersonic projectiles. Except for shooting your gun up in the air to test “if your silencer is silencing”, this catalog is very informative. I hope you enjoyed reading along.