Does anyone have any experience with them? Recommend them?
Does the fin sizer allow you to use the barrel on multiple markers? If you buy a different thread/size? (Similar to the Unitec).

Thanks.

Yep.

Great and surprisingly accurate for the length.

You will need a different 'Fin' attachment for different marker threads

Ion/Impulse
Cocker
Shocker
A5 / X7
98C
WG etc etc...

and the fins also come in various bore sizes.

I think it's a nice barrel. Distinctive popping sound when fired and more accurate then most other 8.5's available due to the rifling. Or there's the Widowmaker which is smaller still but can have a muzzle (to reduce the sound) personally I think it's a bit too small though and I've noticed a large reduction in range but indoors it's a beast. All Hammerhead barrels require a sizer to fit your marker, get a different sizer and the barrel will fit whatever you want.

Superb, just needed that clarifying. Want to get one for my x7. I hear that Swasp is the place to go for Hammerheads?

yes it is, martello who posted 1st is the guy to speak too.

sounds like a quality barrel, may have to invest in one in the furure

i got a hammer head which i love,,

I only use hammerheads these days. I wouldn't shoot anything else.

Same as Al, the sharktooth or the bangstix are the only things i use on all my primary markers.