Increasing Power of an Air Rifle

[aadhaulya]

As mentioned earlier I am not interested in detonation. Lets see.

Regards

[aadhaulya]

I am in Kolkata on official work this week. Therefor by the weekend when I am back I will give my line of thought on how I plan to make it work.

Regards

[airguns]

A dedicated gun...prepared with strength to withstand higher detonation , can be injected with atomised diesel into the swept area by an injector.....can outbeat any magnum powered AR but no more that can be called as AR....may be as DR or diesel rifle.
Just an wild thought inspired by Cadrew..when he says that power in essentially generated by some degree of dieseling/detonation.
Readers are advised not to try it without proper safety precautions.

Basu

Did not work! Eons ago, when hunting was allowed in India, me and my cousin had perfect Diana 27's, full power new imported springs, neoprene breech seals and brand new leather piston washers topped off with half way decent, then locally available, English Milbro Caledonian .22 pellets, the one's in the red tin. Would drop stone dead from 15-30 yards, Pigeons, Crows, doves etc.. But inadequate for ducks, from 30-40 yards.

So we decided to do some experimentation, there was no Doctor Google back then, but the USIS library in N-Delhi had a WHB Smith book of Airguns. It mentioned a German HW air-rifle model produced in the early 1950's, using atomization of Ether into the chamber for a somewhat, questionable and inconsistent gain in velocity. Both of us being Engineering students, we set upon replicating it. Being prudent, not to turn our beloved Diana's into Guinea pigs, we bought a second hand Tommy 35 from a friend. Modifications made, ultra high power spring for causing detonation+hard as hell trigger spring to prevent auto fire, drilled a hole and welded a lockable valved inlet in the compression chamber, attached a atomizer to it.
After much trial and error, best results were as follows. Pre-chrony era, with just powerful spring+neoprene breech seals, the Tommy would nicely make a hole in one side of a square Castrol Tin, just as our stock Diana 27's would. With Ether and also Methyl alcohol vapor injections, sometimes it would penetrate both sides of the same Castrol Tin. Did not try accuracy with that hard as hell trigger, moreover the accuracy concept was foreign to us those days, however despite the gain in power, the experiment was a failure, Ducks, still would not succumb when hit. Breech seals/piston seals popped off every few shots, the air-rifle cracked like a .22 rim fire and in the dark would shot out a streak of flame.

Having not succeeded, we just gave up the idea and went back to using the family Brno .22's for Ducks etc. and the trusted Diana's for Pigeons and Doves.

[brihacharan]

A dedicated gun...prepared with strength to withstand higher detonation , can be injected with atomised diesel into the swept area by an injector.....can outbeat any magnum powered AR but no more that can be called as AR....may be as DR or diesel rifle.
Just an wild thought inspired by Cadrew..when he says that power in essentially generated by some degree of dieseling/detonation.
Readers are advised not to try it without proper safety precautions.

Basu

Did not work! Eons ago, when hunting was allowed in India, me and my cousin had perfect Diana 27's, full power new imported springs, neoprene breech seals and brand new leather piston washers topped off with half way decent, then locally available, English Milbro Caledonian .22 pellets, the one's in the red tin. Would drop stone dead from 15-30 yards, Pigeons, Crows, doves etc.. But inadequate for ducks, from 30-40 yards.

So we decided to do some experimentation, there was no Doctor Google back then, but the USIS library in N-Delhi had a WHB Smith book of Airguns. It mentioned a German HW air-rifle model produced in the early 1950's, using atomization of Ether into the chamber for a somewhat, questionable and inconsistent gain in velocity. Both of us being Engineering students, we set upon replicating it. Being prudent, not to turn our beloved Diana's into Guinea pigs, we bought a second hand Tommy 35 from a friend. Modifications made, ultra high power spring for causing detonation+hard as hell trigger spring to prevent auto fire, drilled a hole and welded a lockable valved inlet in the compression chamber, attached a atomizer to it.
After much trial and error, best results were as follows. Pre-chrony era, with just powerful spring+neoprene breech seals, the Tommy would nicely make a hole in one side of a square Castrol Tin, just as our stock Diana 27's would. With Ether and also Methyl alcohol vapor injections, sometimes it would penetrate both sides of the same Castrol Tin. Did not try accuracy with that hard as hell trigger, moreover the accuracy concept was foreign to us those days, however despite the gain in power, the experiment was a failure, Ducks, still would not succumb when hit. Breech seals/piston seals popped off every few shots, the air-rifle cracked like a .22 rim fire and in the dark would shot out a streak of flame.

Having not succeeded, we just gave up the idea and went back to using the family Brno .22's for Ducks etc. and the trusted Diana's for Pigeons and Doves.

Reminded me of the" time tested fool-hardiness - regardless of warning"
Eg: The sticker on the park bench says - "WET PAINT"...but then one has to put a finger on it to find out
Some even sit to find out
Briha

[brihacharan]

DAMAGES CAUSED BY DIESELING
Dieseling is the ignition of a fuel resulting from the heat generated by the compression of air in a cylinder. When the air within a spring-piston air gun’s receiver tube is compressed, the temperature of the air rises to a very high level, igniting the tiny oil droplets that lubricate the piston seal and walls of the compression chamber. Thus, a detonation can result.

Dieseling in an air rifle is natural due to the lubrication required for smooth operation, but too much lubrication can be damaging to your air gun, and may even result in injury to you or others. This is why we stress that you use a specified amount of lubrication for all of your air rifles.

The accompanying picture of a broken spring is an example of what may happen if you over-lubricate your air rifle. The excessive amounts of oil can detonate, creating a powerful force within the receiver tube that violently slams the piston into the spring. When conditions are right, or rather wrong in this case, the force can cause the internal spring to break, rendering the rifle unusable.



The same thing can happen if you use the wrong type of lubricant. You should avoid using petroleum-based lubricants in your air rifle. These lubes are more prone to combustion and some formulas are known to deteriorate the piston’s seal.

While a broken spring due to over-lubricating is one of the worst things you can do to your spring-piston rifle, excessive dieseling can also lead to tears in the piston seal, causing a decrease in power and consequently, the velocity.

If you have an air rifle that has been over-lubed, or lubed with petroleum-based oil, the best and safest thing you can do is to disassemble and clean your air rifle.

Ref: Dieseling Air Rifles - Umarex USA - blog.umarexusa.com/dieseling-air-rifles/
Briha

[aadhaulya]

Reminded me of the" time tested fool-hardiness - regardless of warning"
Eg: The sticker on the park bench says - "WET PAINT"...but then one has to put a finger on it to find out
Some even sit to find out
Briha

Briha ji, there are some stupid people who have a wild streak (can be called streak of madness) in them, when they do not except the obvious. Even at this age I have that streak in me.
I would go and touch the paint to find out if the sticker is not very old and the paint has dried long ago. Only nobody bothered to remove the sticker.

Eg. I was also told that getting an Arms License is next to impossible unless you have some solid contact and between Rs 3 to 7 Lacs to spare. But the wild streak took over and I put a brake to my regular work and devoted 20 days to the LA and to every ones surprise got it within that time period of 20 days.
Then I decided that it must have been a matter of chance so I went ahead with an application for two additional weapons. That took another 25 days to come through.

I am built that way and like to push my luck/ fate as far as it would go.
But I am not justifying this action, a normal person should toe the line and he will remain happy and satisfied with life.

In my line of thinking I get frustrated also sometimes on finding out that the paint was actually wet. Some times I am satisfied by finding out that the paint was dry and the sticker was not removed.
Actually what I should have done is moved on and let someone else find out. After all it is not my personal bench.

Regards

[brihacharan]

In my line of thinking I get frustrated also sometimes on finding out that the paint was actually wet. Some times I am satisfied by finding out that the paint was dry and the sticker was not removed.
Regards

When someone asked Thomas Alva Edison why he failed 1140 times while he invented the 'Electric Light Bulb', his reply was -
"Well I learned how not to repeat those mistakes again"

Experimentation leads to Experience - Learning that help acquire knowledge
Briha

[aadhaulya]

Oh boy... Did he have time on his hands....................
I would give up after about 5 attempts and scrap the project.

Also if Edison had the internet he would have come to know that there is nothing called the "Electric Light Bulb' and would not have wasted his time on 1140 experiments.

Regards

[goodboy_mentor]

I am starting on the theoretical part to calculate what I want and then decide if it is achievable or not.

Energy = mass*speed of light^2 is not applicable in your case. It is not formula for kinetic energy used in ballistics but about theory of relativity that says mass can turn into energy and energy can turn into mass under certain conditions. It is used in nuclear physics.

The formula Kinetic Energy = 1/2mass*velocity^2 will be applicable in your case under ideal conditions i.e. in vacuum with no gravity or other forces acting on the projectile. But there are many more variables that come into play in ballistics. Therefore even this formula will not be accurate or correct. In your case the air resistance or drag, the spin rate, shape and mass of the projectile will play their roles. Just search for "drag physics" on the net you will get an idea. In short it means more the velocity of pellet, more drag it will face, resulting in inaccuracy as well as decrease in velocity due to air resistance and turbulence around it.

Because of air resistance, increase in velocity is not going to increase the range indefinitely. For example when you shoot bunch of small projectiles from shot gun they do not go very far but spread quickly due to air resistance and turbulence. But a large slug goes comparatively very far. Why? Because heavier slug carries more energy and thus comparatively less susceptible to resistance and turbulence. Similarly if you want to increase the range of air rifle you will have to increase the mass of projectile, its shape and spin rate accordingly. Only increasing air pressure or barrel length is not going to produce very good or accurate results.

For more detailed information, may search net for "ballistic flight equation" "horizontal terminal velocity" "mass air drag equation" etc.

[aadhaulya]

Good information GBM. I will have to do some more research on these topics before finalizing my calculations. Off course the calculations would not be even near perfect as that is a design aspect, but I hape to get comparable data with what is available, to decide if I would get some significant result or not.

Regards

[aadhaulya]

mass*speed of light^2 is not applicable in your case. It is not formula for kinetic energy used in ballistics but about theory of relativity that says mass can turn into energy and energy can turn into mass under certain conditions. It is used in nuclear physics.

The formula Kinetic Energy = 1/2mass*velocity^2 will be applicable in your case under ideal conditions i.e. in vacuum with no gravity or other forces acting on the projectile.

I still didn't understand why a formula of nuclear physics can't be used in every day life. But today I was discussing the formula with my wife who is a PG in Chemistry and not an engineer. The first thing she told me was the same thing that it is used in nuclear physics and c= speed of light.
no wonder I was a '5 point someone' engineer. And she reminded me again that she would not have married me, if she had seen my mark sheets before marriage.

Well I am back to the 'drawing board'

Regards

[timmy]

For example when you shoot bunch of small projectiles from shot gun they do not go very far but spread quickly due to air resistance and turbulence. But a large slug goes comparatively very far. Why? Because heavier slug carries more energy and thus comparatively less susceptible to resistance and turbulence.

It is important to recall that, when the dimensions of a projectile are increased, the volume (and, therefore, the mass, if the projectile is solid) increases more rapidly. To put this into crude bullet terms, if you increase the length of the projectile, the surface area (related to drag) will increase linearly, but the volume will increase civically. If you increase the diameter (bore) of a bullet, the surface area in teases by the square, but the volume increases cubically.

Because increasing the mass is related to how much energy the bullet can store, one. An see that a larger bullet has the potential to store more energy for a given surface area (and therefore, drag). Given the same velocity and shape, the larger bullet can go farther. This is why longer range target and varmint shooters use 6mm over .22 and.many sniper rifles have moved up from .30 cal. to ,338 and even .50 BMG. The larger bullet has more range potential.

[goodboy_mentor]

I still didn't understand why a formula of nuclear physics can't be used in every day life.

Because E = mc^2 says that if you propel a mass at square of the speed of light, the mass will transform into energy. It is Einstein's theory of relativity. Also because we cannot propel anything at the square of speed of light or even at the speed of light in our every day life. Speed of light is around 300,000 kilometers per second. Speed of rifle bullet is around 800 meters per second. Speed of sound in air is around 330 meters per second. Anything moving below the square of speed of light is irrelevant for E = mc^2.

It is important to recall that, when the dimensions of a projectile are increased, the volume (and, therefore, the mass, if the projectile is solid) increases more rapidly. To put this into crude bullet terms, if you increase the length of the projectile, the surface area (related to drag) will increase linearly, but the volume will increase civically. If you increase the diameter (bore) of a bullet, the surface area in teases by the square, but the volume increases cubically.

Because increasing the mass is related to how much energy the bullet can store, one. An see that a larger bullet has the potential to store more energy for a given surface area (and therefore, drag). Given the same velocity and shape, the larger bullet can go farther. This is why longer range target and varmint shooters use 6mm over .22 and.many sniper rifles have moved up from .30 cal. to ,338 and even .50 BMG. The larger bullet has more range potential.

Yes. A lighter bullet carries less potential energy. It's energy is mainly due to velocity. But when met with resistance, this kinetic energy is lost very fast since it is squarely proportional to velocity. Was reading somewhere on internet about experiments comparing the range and penetration of 7.92 x 57 mm cartridge and 7.62 x 63 mm cartridge. As compared with 7.62 x 63 mm cartridge, 7.92 x 57 mm cartridge had better penetration and range.

[essdee1972]

Ye gods! Time travel with an airgun!!

[brihacharan]

Ye gods! Time travel with an airgun!!

Briha