disco .177 help please

[dwalker123]

My son and I have 2 discos. Bought new at the same time. All stock. My rifle is shooting steady 940-950 fps for 20 shots. At max fill psi 2000. My sons is shooting 995 fps and drasticly drops below 900 fps by shot 11. At shot 20, he is already down to 663 fps. Help. He is getting frustrated and so am I.

[Tommy]

Is his the .22?
Tommy

[clgraham82]

Most of the new discos are only getting around 12 usable shots from 2000-1000 psi.  Believed that Crosman is sending them out with larger hammer springs which gives higher fps but fewer shots.  On my third one from Crosman and all three were getting the same low shot count...very frustrating!

[yonip69]

Welcome to the GTA !!

[mudduck48]

Welcome to the GTA. 

[dwalker123]

Both of them are .177

[Tommy]

Switch springs and see what happens.
Tommy

[dwalker123]

Swap the 2 guns hammer springs to see if the problem moves to the other gun? I did check the serial numbers, mine was made 1/13 and his ( the one wjth the issue) was made 3/14 if that means anything.

[Tommy]

I dont know about the dates but switching springs is easy and you can eliminate one thing.
Yes the hammer springs
Tommy

[amb5500c]

Welcome to the GTA.
Richard

[dwalker123]

Thank you Tom. Will give it a shot. Let you know howmit goes.

[Speedly]

I too have a .177, and I'm quite happy with it. My main question is, what pellets are you shooting, at what weight?