I don't have any experience with this particular gun but essentially any speargun once you strip it down, is just a muzzle to hold the rubbers, a mech to hold the spear, a trigger to release it and a tube or wood to separate the two and allow the rubbers to be stretched. I don't see why that gun shouldn't work fine, two things to bare in mind, change the wire wishbones, they can snap without warning and really cause injury and make sure the mech is still working ok. Once you've done that, clean the spear head and probably change the shooting line. A few simple tweaks and your good to go, these days people get too hung up on this spearguns better than that one, especially when starting out, take it in the sea, get comfortable out there and enjoy yourself. Starting with simple stuff is better than the all the gear, no idea brigade, don't purchase expensive stuff when starting out because you will find out what you really need as you progress, different length, band configuration, pneumatic etc. That gun will be fine for small fish and when starting out that's what you should be going for, the biggest thing is learning to be comfortable in the sea, the rest falls into place............. well I think so anyway, Good luck and dive safe
