I once made a mini combustion (around a 400ml chamber) using Acrylic for said chamber. It had a fan and used metered Butane, it was quite powerful for it's size. The chamber you are planning on using should be fine for a while, but could change it's mind a blow up in the future.
My cannon was fine but i retired it because i realised as said above that it was a frag grenade waiting to go boom. That and the fan shat itself.
Your chamber seems like it may be Polycarbonate, that would be fine to use.
If it has a bit of give like you said i don't see any reason not to use it. It's only 110mm long and 60mm dia.
Having said that, it is up to the individual to decide what is safe and what is not, after all it's your cannon and heartbeat!
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