Rubber and Shaft Choices on a 100cm Gun

[Jed]

Hi all,
I own a 100cm Beuchat Mundial speargun and was looking for advice on it.

It's my first gun and I've been looking at upgrading it more and more to suit my conditions. Currently it has the stock closed muzzle with one 16mm band equipped.

Was looking at purchasing a new spear, muzzle and rigging new bands to it.
I've done a bit of research and think I'm gonna go for a 7mm spring steel shaft (mine is getting a bit worn and the flopper is too small) and 2x 16mm or 2x 14mm rubbers, or even a single 18-20mm band? I'm just not sure which option would be better since the size of my gun isn't great and I've heard adding too much power decreases accuracy and also sometimes guns aren't built for that kind of stress?

Also with the new muzzle I'm looking at, it's a Beuchat Marlin Aluminium open-muzzle, not sure whether it's the right option for two reasons; it's aluminium and I've read some bad things about that and also it's plainly an open muzzle. Was looking at the Rob Allen low-profile muzzles and whatnot but as far as I'm concerned nothing else will mount properly but a Beuchat one. If I'm wrong could someone please explain how RA ones are mounted because they don't seem to have the hole for the bolt to go through.

Thanks a lot for some answers, couldn't find any for my specific circumstance here.

 

[Mr. X]

Hi Jed,
7mm rubber with double bands mentioned sounds reasonable to me (compare to Rob Allen Tuna model).

Although I've never tried or seen up close the Beuchat Marlin speargun, I has always struck me as a good/interesting option for those dealing with larger fish & clearer waters than we have here, i.e. for folk like yourself is NSW, Oz. I must admit seeing & handling a speargun can make a huge difference to the impression you get of it though. The muzzle design looks very good and clever:

but I would question if you really get much benefit from such cleverness (French cars often have "unusual" features, some very good/useful, some awful, many a bit gimmicky). Also is the shaft holding mechanism sensitive to shaft diameter? Hopefully one of our forum members will see this thread and be able to give us an opinion based on using it.

I believe most European spearguns come in two diameters, 28mm & 25mm - 28mm being the most common these days. I believe SA railguns are 28mm. I think originally there was good interchangeability, so that you could mix & match handles, barrels & muzzles from different manufacturers and perhaps that is still largely the case(?). However, you might run into problems, for example there may be manufacturer-specific or model-specific designs to accommodate thicker-walled carbon barrels or hydro-formed aluminium barrels and/or a rail on the top of the barrel. I see one place in the USA selling them for $13 - at that price just buy one and try it! (and let us know how you got on ).

Re. the RA muzzle, I never removed mine but I believe that it is held in (like the trigger mech.) with plastic dowels rather than screws or bolts - you just need a suitably sized punch or dowel to tap them out. I suspect "unplugging" the muzzle from the barrel might be trickier, especially if they have been in salt water. I believe the muzzle & trigger mech. usually have two rubber O-rings to ensure that they seal tight, e.g. so water-tight at 30m depth.

 

[Jed]

Thanks for your input X, I think I'm going to go with the RA Vecta Low Profile semi-closed muzzle for my gun and then just drill through the barrel carefully and attach it that way since it's not the same locking mechanism.

If I'm doing this, think I might go with the 7mm as I stated and also 2x 14mm rubbers just because I think 16mm might be overpowered for my gun; and the RA Tuna has a 7.5mm with 16mm's aswell.

 

[Mr. X]

Sounds like a reasonable plan. Re. rubbers, we did some back-of-envelope type of estimations of band power combinations & came to the conclusion that 2x14mm would provide similar power to a single 19/20mm band, actually a little more power. It will likely be a lot easier to load though but will likely take a little longer to load, having 2 bands.

The RA muzzle looks interesting. I had the older RA closed "Double rubber"-muzzle (on my RA Sparid railgun) and think it was a good design - gives you a lot more rubber (RA est. 10cm more) than screw-in bands. The semi-closed looks good:

I use 2 Omer XXVs currently. That muzzle can be configured in several different ways. So far I have kept both closed muzzle (the bridge over the top is small/low-profile, removable, clear plastic) - I started out using a closed muzzle so I have stuck with that so far, although I suppose I could try going open muzzle this year, hmm.