Why don't pellet guns lead up?

[Dr.Zubrato]

This isn't necessarily a reloading question, but I figured you guys were the best resource to answer this question.

I cast, as many of you, and we all know how important size, and lube are.

So, why don't pellet guns show lead fouling without lube, especially with such a small projectile at velocities north of 1,000 FPS?

Has anyone tried tumble lubing regular lead pellets?

thanks!

 

[Kernel]

1) No combustion, very little heat.
2) 1,000 fps is still pretty slow, compared to most cartridge guns.

 

[noylj]

Very small bore contact.
Mostly, lack of gas cutting from high pressure high temperature gasses--in fact, expanding gasses in an air gun should be getting colder due to expansion.

 

[rcmodel]

And the bore gets oiled by piston oil vapor every shot.

When the piston & seal is properly oiled with air gun oil, they even smoke a little oil vapor each shot.

Thats all bullet lube on lead bullets do anyway.
All the lube on conventionally lubed cast bullets is in grease grooves on the rear end of the bullet.
The front driving band has no lube on, or in front of it at all.

So, It doesn't lube the bullet you just fired much at all, except the part behind the front grease groove.

It just leaves behind a thin film in the bore that lubes the next bullet you fire.

rc

 

[gamestalker]

I think stating that air guns don't leave lead in the barrel is a little bit inaccurate. I have a few, and they all accumulate a pretty good bit of lead in the barrels, just not as much as a firearm does.

GS

 

[Don McDowell]

Pellets are lubed, much like 22's. And as others have said you have the lack of high pressures with scorching temperature at work. Plus I would about bet if a person went into a pellet gun barrel with a proper sized jag pushing a flannel patch soaked with turpentine that person might be mortified at the stuff found on the patch when it exits the other end of the barrel.

 

[45lcshooter]

some pellets are steel, or have light coating to handle 1000fps. But there is not enough heat to transfer lead from bullet to the rifling of the gun.

 

[Tom_AZ]

1) No combustion, very little heat.
2) 1,000 fps is still pretty slow, compared to most cartridge guns.

exactly. I think the lack of superheated gas behind the pellet is the main factor,

 

[Dr.Zubrato]

Thanks guys!

didn't consider a lot of things before, just thought it was interesting considering how most pellets are soft lead, speeds involved, and lack of lube on the individual pellets

ive shot years and years worth of pellets without ever cleaning the barrel with no loss of accuracy, but never questioned it.
may just clean the barrel for fun, then

 

[Joe Demko]

If you decide to clean yours, do it right. Do not use solvents designed for use in firearms. They may damage seals or detonate.

 

[noylj]

I've shot years and years of .22LR in the same pistols and rifle with no loss of accuracy.
I've shot whole seasons of IPSC and PPC and Bullseye with no loss of accuracy.

 

[Kernel]

If you clean it, take it easy. Air gun barrels aren't made from the same steels as firearms. Even the expensive European ones. It's softer and more prone to damage. Back in the day, some air gun barrels were even made of bronze or brass.

 

[caz223]

The expanding flame front vaporizes lead from the base of the bullet, and the lead vapors condense on the cold (Relatively) barrel.
The pellet is propelled by a short burst of compressed air. Nothing is vaporized.

 

[noylj]

And yet, there is no sign of such ablation on a recovered lead bullet--just flame cutting if the bullet doesn't seal.
I have heard of folks putting thermal paint on the base of the bullet and recovery showed no heat signs on the painted base of the bullet.
The lead has a decent heat content and a very short exposure to the heat.

 

[rsrocket1]

The expanding flame front vaporizes lead from the base of the bullet, and the lead vapors condense on the cold (Relatively) barrel.

I don't think that's quite right, otherwise jacketed exposed base bullets would also lead the barrel. There are many jacketed 45ACP bullets and .223's with exposed bases and they don't lead the barrel. I see overpowder cards on the ground downrange and they aren't even scorched. Shotgun wads are made of plastic and the bases are not melted.

I think it's more of the gas cutting and lube failure (at high speeds) that cause the leading in bullets where pellets don't get the 10-55,000 psi that bullets get.

 

[Blue68f100]

Most pellets have a HB design. My old Sheardan Blue Streak is around 50 yrs old and there has never been any leading. Can't even give you a guess as to how may 1000's I have shot through it.

With 22's rimfire, some bullets will lead and some will not. Rem is the worst when it comes to leading. I will not even buy them they are so bad.

Like all ready said most commercial RN bullets have an exposed base. It's the cutting along the base edge where the leading comes from if it does not seal.