Comp. Pellet Rifles

[Jaybird]

I'm curious if anyone that shoots air rifles treats their pellets with anything?

I ask because a customer of mine has been using one of my products to coat his pellets. I had never even thought of such a use for this particular product.

He was explaining something about some sort of ignition (combustion?) when using other coatings...

Any info for the ignorant?

 

[jimfulco]

Spring-piston air guns create a pretty serious amount of pressure at the peak, and many oils will diesel at that pressure, causing expensive damage to the gun. Oils formulated for use in such guns are designed to resist the tendency to diesel.

If you had a Daisy BB gun when you were a kid, and used something like 3-in-1 oil to lube it up, you are probably familiar with this phenomenon. The first shot post-lube has a definite kick to it, and it launches the BB much faster than usual.

 

[TheLoneRanger]

Very interesting about the oil dieseling in air rifles. I still remember that burning oil smell, after firing my oiled up Daisy pump.

My 5mm Sheridan pellets have a paraffin coating on them for lubrication, similiar to what's used on .22 bullets.
What product were you selling to the guy that used it for a lube?

 

[Cujet]

I have to wonder why the dieseling effect damages the gun. Typically, diesel flame fronts travel at quite a slow speed. While it may be more than the pellet at the outset, it certainly is not after the pellet gets to the end of the barrel.

Chris

 

[tom slick]

the compressed air would have to get really hot for the oil to combust. I would think the rifle would get hot also.

 

[JHZR2]

isnt the expansion of gas from such a system isenthalpic? If so, the expansion should cause the gas to cool...

 

[springnr]

I use Finish Line Krytech wax lube for pellets that are used in my spring air guns as it will not cause detonation.

FP-10 and slick 50 one lube are good for use in Pneumatic guns. These will not gum up or attack the seals.

Spring guns do diesel. Trace amounts of lube make it past the seal into the compression chamber and at peak compression the temperature spike results in a very lean burn. This is normal.

A poor seal, introduction of oil/grease on the pellet, or through the transfer port provides a lot of fuel. If too much you can see a spray out the barrel but is too wet to ignite. At some point the ratio will be right though and you will get a sustained burn aka detonation. This often continues for many shots till the fuel is used up. Detonation can burn seals and break springs. Some times one detonation is enough to kink a spring.

 

[springnr]

I can't find the source in my books but I recall the temperature when the air is compressed gets pretty high. I imagine the mass of the airguns metal coupled with the short duration of the temp spike keep things from getting to hot.

Fire pistons work on the same principal.
http://www.wildersol.com/

 

[Quickbeam]

Wkipeida has a pretty good write up on air guns. It mentions the oil and compression thing: http://tinyurl.com/yx7j9k

 

[chevrofreak]

Quote:

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Wkipeida has a pretty good write up on air guns. It mentions the oil and compression thing: http://tinyurl.com/yx7j9k

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Wow, small world.

 

[chevrofreak]

Quote:

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Quote:

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Wkipeida has a pretty good write up on air guns. It mentions the oil and compression thing: http://tinyurl.com/yx7j9k

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Wow, small world.

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Nevermind, looks like you're a different Quickbeam.

 

[Quickbeam]

It's still small. I'm a CPF member, I just stole his handle rather than use my own

 

[chevrofreak]

HAH!