Crosman Fire Nitro Piston .177

[FirstTimeShooter]

Hello Everyone,

I am new to the world of air rifles and I was wondering if anyone else out there had the same questions/concerns I did about this airgun. I recently purchased this rifle (Crosman Fire Nitro Piston .177)after watching some modification videos that had looked promising to increase my fps (I am from Canada, therefore the initial fps is only 495). I have just disassembled my rifle and noticed right away that the piston was different. There is a bleedhole, but it is located on the top of the piston rather than being directly right through (I will cover that bleedhole up with some JB Weld). Also, there is a gaping hole/area that I am wondering if I should plug? This gaping area I am referring too does not go all the way through - it is just a “pit” almost. I will attach photos to explain.

So the main question: what modifications can I make to the piston itself if it’s this version? (I imagine they have updated the piston over the years to prevent these easier modifications from occurring)
I also noticed that my nitro piston is the BT5M version - I saw a video where the highest powered nitro piston is the BT9M, is there anyone that can help me find where to purchase this? Or do i have to buy a “tuning kit” or whatever they are referred to as. Any help or insight would be greatly appreciated!!
(Photo 1= bleedhole at top of piston on a different angle
Photo 2= gaping hole that doesn’t go anywhere)

[Dukemeister]

hi and welcome, read this
topic85404.html

[oldfart]

I've never seen such combination of bleedhole and extra cavity but it makes sense that, if you have a full power nitro piston and a short piston body, that they have to have this extra cavity in order to reduce the output air to the barrel/pellet.

Sorry i can't help and i realize this is old but i figured i would voice my curiosity and opinion on this.

Take care, enjoy!