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jeffery7466

Quick Joule Test Using a Coke Can

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Hello guys,

 

I am not sure if you guys knew this, but a quick way to (roughly) test the energy of a gun is by shooting into a coke can.

Using 0.2g bb pellets, hold the muzzle about half an inch away from the surface of the can, at right angle, holding the can in place:

  • Shooting into the side, if the pellet penetrates only one side and remains in the can >1 joule
  • If the pellet penetrates one side and tears (not a clean, round hole) through the other ~1.2 joules
  • If the pellet penetrates both sides cleanly (nice round holes) ~1.4 joules
  • Shooting into the bottom of the can, if the pellet penetrates the centre of the bottom ~1.6 joules
  • If the pellet penetrates near the rim of the can ~1.8 joules

This is the case with the older 350ml cans, but they only selling the slightly thinner 330ml cans now. Shouldn't make much of a difference, but please do bear this in mind!

Convert the energy into fps or m/s using the kinetic energy equation we all loved from school - E=0.5*mass(kg)*speed(m/s)^2

 

350fps with 0.2g pellet is about 1.14 joules.

 

I hope this helps.

 

Stay safe!

 

EDIT: the can must be empty first!

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So, tell me why my gbb pistol that fires consistently at 290fps (i own a madbull chrono) can penetrate a coke can from half an inch away????

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This is the case with the older 350ml cans, but they only selling the slightly thinner 330ml cans now. Shouldn't make much of a difference, but please do bear this in mind!

 

Shouldnt make much of a difference??? It makes a hell a lot of a difference. Plus the materials change between cans. Some are aluminium alloys, some are steel alloys.

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essentially, it's not a poor man's chrono it's a feed of bullshit.

 

you wanna know how hot your gun is shooting? chrono it.

 

Exactly, this post is arsegravy of the lowest order.

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Exactly, this post is arsegravy of the lowest order.

 

All right, I see how this is :unsure:

 

This is just meant to be a crude test and did work to a certain extent.

 

Screw you guys, I am going home :(

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All right, I see how this is :unsure:

 

This is just meant to be a crude test and did work to a certain extent.

 

Screw you guys, I am going home :(

good idea :P

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With all due respect but there has been numerous posts like this in the airgun community involving the use of a yellow pages phone book with similar replies to this thread.

 

The only way is to use a proper chrono as various factors have effects on velocities.

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^^^ its like reading a ukara debate all over again lol :)

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