RA Spearguns + PNG

Slip Tips

In general, I don't really like slip tips.

I've found that it's fairly hard to get a decent slip tip, one that fits tight enough not to affect accuracy on long shots, but not too tight to desengage. If you can find one, all the better. The general idea behind a slip-tip is good, but the implemetation is normally not good enough.

Just a thought ....

SLIP TIP

Guys,

Riffe has a Slip Tip called the Ice Pick even for 6mm thread end. However this tip is good only for high power guns cause the drag is high, but the grip is deadly. Not suitable for surf area though.
I been using it with 5/16" ( 8mm) & 3/8" (9.5mm) shafts and result is good, with under 7mm shaft, I don't know cause it is quite heavy.

Penetration wise this pencil point is not a winner, but the hole it made is sweet and clean. Sometimes I get tummy shot and it can hold well without much tearing, unlike tri cut detachable. The Riffe Ice Pick is a very well made slip-tip, stable during flight, will drop off on its own weight or by a fish trying to break free. Even if the penetration is not completely over the other side, as long as there is fish flesh to grip, it work wonderfully inside the flesh. My gang entirely use this Riffe slip tip, even on occasional grouper around the wreck. It work well as long as there is 6" of free space behind the grouper. We only target the red grouper ( aka Rock Cod ) and this stealthy fish always give only the face/head and like only 5" x 5" wide target. We don't wait for it to turn side way, we aim at the jaw. If the fish is close enough, the shaft will stake it thru till the tail. If it is say 3 meters away, in most cases it has enough time to spin around and almost a guarantee that it become a gill shot. Somehow this fish likes to spin on its on axis.

If it flee we aim the ass, and usually the shaft will penetrate all the way to the head.

However my 5/16 shaft with ice pick is MUCH slower, shoot less further than a 5/16 Hawaiian Flopper. Well can't win everything.


IYA

Strong Rubbers and Slip tips

with the rubbers story-
maybe the barrel is still a bit weak for the muliple bands despite it being wider, thicker walled and better grade aluminium than standard euro guns + the added benefit of the rail. does anyone know the actual dims of a rob allen barrel, and that of a riffe?
maybe thats one of the reasons that the RA handle doesnt handle that much.

also, check out the rob allen website www.roballen.co.za for info about slip tips (FAQ). just keep in mind that the advice is subjective, but most of it makes sense

Mark

Strong Rubbers and Slip tips

with the rubbers story-
maybe the barrel is still a bit weak for the muliple bands despite it being wider, thicker walled and better grade aluminium than standard euro guns + the added benefit of the rail. does anyone know the actual dims of a rob allen barrel, and that of a riffe?
maybe thats one of the reasons that the RA handle doesnt handle that much.

also, check out the rob allen website www.roballen.co.za for info about slip tips (FAQ). just keep in mind that the advice is subjective, but most of it makes sense

Mark

Just to set the record straight ....

Straight from the horse's assistant's mouth ...

Hi Riaan,

The real factor limiting the loading on a gun is accuracy and what you
achieve by it. If you power a gun up the first thing you notice is the
increase in recoil. This will reduce your accuracy somewhat, but an
additional factor is the increase in barrel bending. The rail does help to
keep the point of aim constant, but what it can't do anything about is the
shaft whipping.

When fired from a powerful gun the spear bends a bit and comes out the
muzzle oscillating. This varies the point of aim randomly, but more
importantly slows the spear down. A very powerful gun seems to have a lot of
"power" but after a few meters the spear slows and reduces penetration in
the fish. The effort of loading those over strong bands was for nothing.

We have a graph of single band lengths that we use for various barrel
lengths. By loading with two bands you can increase the power, but not by
too much while still maintaining accuracy and penetration. We recommend two
16mm bands because of this.

We had a guy who overloaded his guns in our opinion. We measured the pull
and it was in the region of 90 - 100 kg. He lengthened the bands to about 60
kg and was much happier with the results. The average guy uses a pull of
about 45 - 50 kg with a single band on a 130 cm gun. We have never heard of
a gun misfiring without there being some fault with the mech or spear and
have never been able to test a mech except by loading a tray held by a
length of spear to about 150 kg ( in this case two people standing on it.

Cheers,

Jeremy

Dive Factory

181 Gale Street,
Durban 4001
South Africa

Tel: +27 31 3012241
Fax: +27 31 3012247
Email: divefac@iafrica.com
Web: www.roballen.co.za

Click to expand...

There you have it.

The more I know, the more I get confused

DogMatrix,

First u must like Asterik comics, I do. I was wondering where I read the virtual name like yours.

PNG ( Papua New Guniea ) is half of a big ( look like a dinosorous on the map ) island whereby the other half belongs to my country Indonesia. I was told the waters there is fantastic. Happy Hunting.

I am too just figuring out on the reply from Jeremy of RA. Somehow there could be a possible misunderstood data for the RA owners.

Let me ask you if your RA guns come with the instruction manual that stated maximum reccomended rubber diameter or the quantity for them in combination ( double rubber muzzle ). I look at the RA website, there is no information on the maximum safe rubber pressure loading. All I got is they have a new double rubber muzzle that can take up to 20mm because of user demand. Does this means the double rubber muzzle can take 20mm x 2 rubbers ? If the 2 rubber holes/slot is bored for 2 x 20mm shouldn't the trigger be designed to acccomodate for this new double rubber muzzle ? Why would one design a double muzzle to overload its own trigger ? Doesn't make sense.

To any spearo, if a gun's instruction manual does not state trigger reccomended limitation, he will definitely one day...... place the maximum amount and diameter of rubbers as he see fitting for the muzzle, this is logic.

Thanks to SASpearo for the info from RA guys, now we can be assured that 16mm x 2 is the best choice.

We had a guy who overloaded his guns in our opinion. We measured the pull and it was in the region of 90 - 100 kg.

Click to expand...

We have a graph of single band lengths that we use for various barrel lengths. By loading with two bands you can increase the power, but not by too much while still maintaining accuracy and penetration. We recommend two 16mm bands because of this.

Click to expand...

However, I am again confused with Jeremy's reply because I have been using Riffe's rubber and literature as the measure of rubber pressure, since it is the easiest document to obtain and they are very reputable, thus very reliable info. The same rubber presure info is available from Internet Custom Speargun and Terry Maas Blue Water Hunter book.

Riffe stated 16mm ( 5/8" ) rubber pressure at 110 lb ( 50 kg ). What if an RA owner replaced RA original 16mm x 2 with Riffe rubber because Riffe rubber is easier to source around his area. Would not the total trigger loading pressure be at 100Kg and thus not reccomended ( accuracy wise ) but diameter wise the rubber is reccomended ?

I know how Riffe measured their rubber pressure, it is at 3.2 to 3.3 times rubber stretch length.

Perhaps RA set up the rubber stretch way below 3.2 times or their rubber is much less modulus ?

Rubber maximum pressure will depend on the shaft diameter , we know that and 7.5mm is the thickest RA has to offer. U guys need to research what is the best rubber pressure for a given shaft diameter and perhaps length too. RA should know this.

Jeremy was concerned of the increased barrel bending on high rubber pressure. What is the acceptable limit in rubber pressure can the barrel withstand without bending to the extend of ruining accuracy, if say a spearo willing to go for a 7.5mm shaft to accept more powerful rubbers.

If a 90-100 kg of rubber pressure is assumed as an overloaded situation ( let's put the shaft diameter as "X" ) and 60 Kg ( 132 lbs ) is assumed acceptable, why introduce double muzzle for ?
A single Riffe 3/4" ( 19.5mm ) is already producing 135 lbs of pressure, a 20mm RA rubber can't be that far behind or in fact should be at least 2-3 pound more pressure for the extra 0.5mm thickness.

Confused...confused...confused. So how should I order my RA (soon) ? Why will I pay extra money for a double muzzle that technicaly I can not take advantage of ? One thing for sure, Riffe rubber is the only rubber I will ever use because it is the only good brand there is for me to buy here, in my city and the only brand available in custom length.

Attached a scanned part of Riffe 2001 Catalog on rubber pressure :


CONFUSED,
Iya

DAMN.... Again for the second time the attached photo is way too wide. Mr Mentors, please correct it for me.. please. It sure look out of place.

THANKS
Iya

hi dogmatrix

That guy who Rob allen replied to who had the gun set up with 1 20mm and 1 16mm was me the sear broke from too much pressure it shot off and almost hit my brother the gun is a 110 and was only a year old, I still love the guns but the trigger is by far the weakest point of the gun Stealth railguns make a far better trigger.

cheers

Matrix,

That is the saddest story I heard. What u should do is get a piece of wood as long as your gun and try to practice stalking them. Just make imaginary shot and get as close as your skill allows. At least you can tell by ur imagination if that fish is yours or not. However, I do notice one thing. Everytime I am not armed with a speargun, either empty handed or using a video camera, even with scuba bubbles, fishes just don't mind me approaching them so close, then I use my fingers to do imaginary shot..........whack !!!!

They somehow can sense danger..... they ain't that dumb afterall.

Next time bring ur own gun. Not only different guns shoot differently, having ur own gun making the succesful shot allows you to build confidence in it.

Dive Safe,
IYA

Matrix,

I have a good idea for you. If I go to somewhere I can not shoot but can fish, this is what I do. While diving, get a cheap spool of fishing line and borrow a jigging lure from someone. Since the viz is good there in PNG, jig/fish while diving. The coral trouts/grouper will be the first fish that will take ur lure. It is so fun watching fish come close to the lure because they are attracted and depends how you jig it, they might bite or simply turn away.

I caught a fish this way in Bali's no-shooting spot ............ fun fun fun.

If you say there are albacore around, all you need is a hook and make your own lure. Tie some colourful string of nylon lines, they love it, or steal some squid from tke kitchen. Just catch some fish no matter how you do it, at least u get the thrill.

IYA

Testing of speargun mech's ...

Interesting link, one I came accross whilst researching for my "Frankengun" project.

http://rocknfish.com/Bench_Test.html

Maybe RA should build something like this? I'll probably end up building one for Frankengun, maybe I should hook up my RA mech on that as well ... he he he ....

Good one SA,

Research is a must.......... Rockfish do contain amazing info, I done loaded tons of their data last time. Did I tell you I used my wife's car and my car to pull my shooting line just to know if it fail at the crimps or elsewhere ??? Ha ha ha.


IYA