Boosting pellet rifle performance

[frankrede]

You could try adding a bust-disc to the system, who knows the pressure generated by the detonation might even drive the piston back far enough to recock itself

Now that would be awesome

[CpTn_lAw]

i don't think so, cuz i takes an enormous amount of force to cock the piston. don't forget we are only pushing a 9 grains pellet...according to the M1.v1=M2.v2 formula, and obtaining the mass of the piston you would find something big for v2 = pelet speed. Plus it's a linear spring so this system would need to be studied....i'll try to come back later with some results if joannardway doesn't come first!!

I get some pretty decent recoil with P-B (Potassium bensoate) when i shake the rifle to make it in suspension in the chamber. But as it is a solid (even if it's very very fine grains, more like flour) it makes some residutes in the barrel, and take two regular pellets to clean. I'm gonna buy some pellet today, different types, so i'll show some pics, even a little video.

For information, do you remember tje BB magnum by Mark? (spudinator)
Well, i had talked to him a lot about it, and he claimed a speed of 1200-1600 fps with one N°209 cap and a copper BB. He said a BB could penetrate 3cm of wood.
Well, i've shot a TS-10 pellet yesterday through some wood...3.5cm of penetration, where my airrifle without any combustion effect would score 1cm. (200m/s average)
plus i've made distance hit report, at 100 meters, i shoot a pellet against a tree. i hear the pelet hitting one second after shooting. With 0,5 grams of postassiu bensoate behind the pellet it takes 0.5 seconds to hear it hit.
considering that the sound takes 0.3 seconds to come back to me, and that the loss of velocity for the pellet is of 50m/s, we get approx 400m/s as a muzzle velocity. which is consistent with the rest of the tests.
Again, it's only a 9 grains .177 pellet.

[jackssmirkingrevenge]

I was being sarcastic... but it's interesting to note that there have been cases in powerful springers where excessive dieseling has blown the cylinder, so in that scenario if the piston is actually blown back with enough force to engage the trigger sear, you can throw the gun away.

[CpTn_lAw]

Lol mine is a 10 joules one, so....I think i'd really need to put some excessive amount of fuel to make it explode!!!



Edit, wow, i don't know the noise of a .22lr rifle, but the last shot i made was damn loud!! i scared myself!!! i definatley did a supersonic shot.

[jackssmirkingrevenge]

out of curiousity, what model is it?

[CpTn_lAw]

lol i'm using a gamo shadow 1000. the 10 joules version.

FeLeX wrote:
So I mean is it really worth it? On avera by how much fps can it be increased? Could this be used to make a unique mini hybrid?


It has increased the power of my air rifle by 100%...660 fps increase with potassium benzoate (whistling mixture)
And it increase the performances by 30-35% with grease.
I'm surely gonna buy a little piston pistol, and make it a little more powerful lol!!

[jackssmirkingrevenge]

ah, nothing finely engineered then *phew*

Did you actually chrono the pellets, and if so, how?

[CpTn_lAw]

i didn't chrono the pellets, i used the distance and the sound recording.
I removed the 0.3 seconds of the hitting noise coming to the microphone, and took a table on the internet where the pellet's velocity decrease was writen. and i managed to give an approximation.

[CpTn_lAw]

So, here are some pics.....
First one, shot a flat-head wadcutter pellet in a piece of wood. 3cm of penetration, the pelet ended behind, in a piece of styrofoam.

second shot: a TS-10 with 0,2 grams of potassium benzoate through a 1mm thick goblet, and a 130 pages magazine.The pellet went completely through and exploded a bit of my garage door.
(notice that the pellet went so fast it didn't simply bent the goblet, it cut rounds in it, i found 'em behing the magazine...)

third , fourth and fifth shot: at a dense brick.
This is dense sandstone, really dense. A brick compared to that is hard like cotton. left impact from 5 meters away, wadcutter. note pieces of lead remained encrusted.
Right shot from 10 cm away, notice the burn. The TS-10 this time completely exploded, sending little piece everywhere. lead remained encrusted.
Third shot, from 10 meter away, on the bottom center-left, notice a crack. the pellet was cut in half, like with a very very sharp knife.


Enjoy...lol I was wearing polycarbonate glasses , a neoprene mask, and after the first shot, earing protections...lol.

[chaos]

nice as, but i don't get the "burn mark". isnt it an air rifle?

EDIT: never mind im just wasnt thinking when wrote this.

[CpTn_lAw]

looooool using some fast burning powder mixed with air to form an explosive gaz creates a flame lol, like a hybrid. OH, i've tested the real diesel fuel.....not to make...definately not a thing to make, very loud, stinks, and gives a hell of a kick.

[joannaardway]

My Uncle had an air rifle that would do much the same when the mix was right - it would put a pellet through a road sign more often than not.

[CpTn_lAw]

lol, i'm dealing with a lot more power than that lol, i blew two 3/4" wooden board...

[joannaardway]

I wouldn't say so. Air cannons that will put holes through 2" of MDF (which is pretty much as tough as you can get) with ease, struggle against a road sign (or rather, it's equivalent - blowing holes in road signs gets lots of attention)

[CpTn_lAw]

Lol, the most powerful air rifle, and by air rifle i mean pellet rifle, is something like the gamo 1250, which scores a 380m/s as an initial velocity...
I get 400 m/s with some powder behind the pellet. That' more powerful than the gamo 1250.
And, pushing a 11 grain pellet to this velocity makes my rifle developp an initial kinectic energy of 44 joules!!
My marble canon developped 140 joules, but with a 3 grams projectile. putting holes through roadsigns isn't that heroic lol!