air rifle spring

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ratherbefishin

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is there any practical way of increasing the velocity of a a crossman backpacker air rifle by installing a heavier spring?
 
ratherbefishin said:
is there any practical way of increasing the velocity of a a crossman backpacker air rifle by installing a heavier spring?
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If you could find one that fits, probably YES...BUT if your "new" pellet velocity exceeds 500'/second, you will have a "firearm" and will have to register it. I believe modifying that air rifle would make it illegal but I'm not a lawyer. Seek advice before proceeding..you never know.
 
Yup. Heavier hammer pring/lighter valve spring will make for faster opening/increased duration.....but not really worth it for the amount of hassle.

The most common mods (In the states, where its legal) is to fill the bleed hole in the valve, replace the restrictive transfer port with 1/4" polyvinyl, and decrease (yes DE-crease) the valve volume by about 20%.

I used to tune the crosmans as a hobby/side business.

Ryan

Ryan
 
Crosman makes higher-velocity versions of all their airguns for sale in the US (where the 500 fps cut-off isn't an issue), but they won't ship the valving units to Canada.
 
Under our laws, I'm sure that would be considered the same as importing the airgun itself, complete with all the hassles that go with it.
 
If you order an exhaust/poppet valve from Crosman Canada you get the US version (no bleed hole, US transfer port specs).
Modding the Crosman 2289G Backpacker is easy to do, but can also put you over the 500fps/4.2fpe/5.7joules limit if your not careful. You CANNOT register it once you modify it, it becomes an ILLEGAL firearm.
Usable mods in Canada are for accuracy, durability and efficiency. Check out the US Crosman forum, they have tons of info for the budding mod meister.
http://www.network54.com/Index/12861
Enjoy...modding airguns becomes addictive. With a chronograph you get to see what your tinkering does very quickly.
Threemorewishes
 
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so, in practical terms,if you did modify your crossman backpacker-and it did happen exceed the 500FPS ''limit''-how would anyone determine that-do the authorities go around and chrono them?
 
python357 said:
If you could find one that fits, probably YES...BUT if your "new" pellet velocity exceeds 500'/second, you will have a "firearm" and will have to register it. I believe modifying that air rifle would make it illegal but I'm not a lawyer. Seek advice before proceeding..you never know.
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This is not true. It must also exceed the energy requirement which does give you some wiggle room with .177 on the muzzle velocity.

1. Air guns that are firearms for purposes of both the Firearms Act and the Criminal Code.

These are air guns with both a high muzzle velocity (greater than 152.4 meters or 500 feet per second) and a high muzzle energy (greater than 5.7 joules or 4.2 foot-pounds). The “muzzle velocity” is the speed of a projectile at the instant it leaves the muzzle of a gun, normally expressed in metres per second or feet per second. The “muzzle energy” is the energy of a projectile at the instant it leaves the muzzle of a gun, expressed in joules or foot-pounds. Air guns need to meet both standards to be classified as firearms for purposes of the Firearms Act.
 
I need to clarify something right up fornt....the backpacker is pneumatic...not spring powered.. In fact, there are only 5 springs in the entire gun. The trigger spring, safety detent ball spring, stock attachment nub spring, valve spring and hammer spring. The 2289 (backpacker) is .22 only, so it takes a bit of work to get above the legal limit 499.99 fps. just filling the bleed hole in the back end of the alve will get you above 450, with the transfer port modded (as I explained earlier) you will be very close to the 500 limit. So close, in fact, you might want to chrony it with standard pellets (14.3 gr.) to make sure you ae not over.
 
putting air rifles in the same catagory as regular firearms if they exceed 500fps does sound a bit rediculous allright-and I wonder who or why they came up the idea in the first place-one hardly chooses an air rifle for criminal purposes
 
I guess they had to draw the line somewhere - you could make a 50 cal airgun that had respectable (deadly) muzzle energy and probably keep it under 500 fps.

What you don't want to screw with is making a pistol over 500fps. = RESTRICTED.
 
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