I don' agree with Jim about many things he posts but this one he hit it bang on. I have used air rifles since I was a kid at 7 yrs old. I shot my fair share of critters in my days and have come to regret a lot of that ... there was really no reason other than to sharpen my marksmanship but I could have set up some beer cans for that ... other than the fact that moving targets are much more challenging ... sparrows are the hardest.

Anyway, all my regrets out of the way ...

Dieseling an air rifle DOES increase the fps of the rifle BUT as he correctly stated ... if you over do it ... it WILL kill the seals in the rifle faster than not.
Take a Q-tip and very lightly oil the air skirt of the pellet ... this is ALL that is required for the increase and will save the seals in the rifle.
There is also the type of oil or whatever that you can use.
I saw one post on a forum where they used WD40 or even PET Ether ! for col starting engines ... haven't tried that one yet but can imagine it would really give a big boost but be very careful !

Another air rifle friend of mine who actually got me back into them suggested vaseline or parafin wax ... probably not as good as WD40 or PET Ether but lasts longer in the long run.
For those preppers that don't want to waste gun powder rounds on small game for food ... an air gun with high fps is the way to go ... add a little dieseling to it and you can start taking down larger game.
The guy who suggested using WD40 said his rifle went super-sonic ... sounded like a .22 long rifle shell.
Apparently Jim bought an air rifle and was disappointed that it wasn't just a plain old springer type but was a nitro piston type which in most cases is already super sonic nearly but after seeing what it could do to say plywood of varying thickness he was impressed to say the least.

If one jumps on Utube of all places ... there are many vids for modding and upgrading air rifles ... just be sure you are legal where you live and yer good to go for using air rifles for small game unless you have a pcp unit at high caliber and then you can bring down even larger game like small deer or wild pigs.

For the preppers ...
Journey