C_F_45
>>What happens if I over-pump a pneumatic air rifle?<< Nothing good will come of it, that's for sure. You do not increase your rifles power by any significant degree, but you can damage it. They are "chipmunks" and I can't think of one good reason to shoot them (?)

jon o
it will break. it puts to much presser on it and breaks the spring and than you can't pump it any more

nightfire
If you really can notice increased power,then go for it. You'll notice that you'll be pumping more and more as the seals go away!

FWC
First of all they are called chipmunks, and what is the point in shooting them? And to answer you'r question, you don't add much power to you'r bb gun and you just damage it, after a while it will not shoot straight and might just break from the inside and then it would be no good.

khartman492000
I had a bb gun I did this to. I ended up blowing out the seal on the air chamber (as you pump, this air chamber gets air compressed into it, much like the tank on an air compressor). Once this air chamber reaches it's full capacity, and you keep pumping, the seal on the intake side (where the air goes in) will blow out and render the gun useless. This is what happened to me anyway.

Ranger J
You will blow out the seal and break your gun. Stop shooting chiPmunks. There is no logical reason to do so.