Rollergun advice?

    Hey everyone, I'm looking for some advice/info on a rollergun setup I'm making


    So here's all the info:


    Its a Mako Predator Pro 2G 120cm that I put a MVD roller muzzle on.


    - 160cm 7.5mm shaft (Mako shaft)
    - 46" from muzzle to last sharkfin
    - 46" from muzzle to anchor point on the bottom of gun (only one anchor point)


    So I have 24" 18mm bands I'm using on the roller. I wanted to stretch it to about 360% or 370%


    I know its gonna be hard to load, but I made one of these (click link) and it helps get the bands out of the roller when there's a lot of pretension. I just want to know if having that kind of tension is safe.


    Easy roller gun loader - Manny Sub


    Any thoughts?

    Hi Gregaz,


    Pretensioning to the barrel/handle coupling works really well!....much easier set up than using the cord through the trigger guard, and it balances the gun a lot better too.


    Couple of things to consider-
    1. pretensioning this much requires a rather long rubber (generally half the length of the barrel) this means the shot will be smoother but slower...not too slow but it is noticeable.


    2. Mvd Muzzles are not made for pretension. (they clearly state this on the flyer/info sheet.
    My go to gun for a while was a 100cm roller much like the setup you have, after a while though, the wishbone stop/elevator became bent in toward the track.


    If you wish to pretension back to the handle I would go with mannysub or aimrite muzzles these are much sturdier.


    Hope this helps.
    dive safe
    Josh

    Dang, I didn't know MVD couldn't take pretension


    I already bought the muzzle and waited 3 weeks for it to come :frustrated1: And I'm going to jamaica in less than 2 weeks so I won't have time (or money lol) to order another one


    I'm only going for a week so I'll probably get 5 or 6 dive trips with it. I hope it can hold up for that time. I'll definitely buy a different one when I come back.


    Question tho: Why is the shot slower? I figured with with pretension and all that band stretch, the shaft would fly outta the gun. My barrel is 120cm so half of that is approx. 24" which is the length of my rubbers.

    ummmm dude you need a liscence to bring a gun into Jamaica, customs will seize your gun bro. Sorry for the rain cloud man :(

    A bad day at sea is better than a good day in the boatyard
    George Steele


    Not sure about Jamaicas customs laws (you should check on that.


    but its still an effective roller muzzle. just cant pretension much. On my 120 i run 21" bands pretensioned just a few inches (just to keep the wishbone on the elevator after the rubber stretches out a bit). these are tied to the trigger guard.


    the shot on long pretensioned bands is slow in comparison to a double banded (hole muzzle) shot.
    It is not really noticable unless you use both styles of speargun a lot and interchangebly. but it is there.


    On my 100cm I run 50cm bands pretensioned to appx 100cm. then this is loaded another 100cm to the sharkfins or notches. I dont have any actual measurements but I feel that a single roller band like this does not put as much pressure on the shaft as two circular bands. The roller will shoot with appx. as much force as the conventional set up, only because of the extended time of acceleration (band stretch). The circular bands will accelerate the shaft faster but for a shorter time (shorter band stretch).


    sorry if this makes no sense.


    good luck
    dive safe,
    Josh

    Akira


    I get what you're saying. But I looked up the info on the MVD roller Pro muzzles and it says it can take 100% pretension. I'm not sure if this means it should have the rubbers just stretched to have no slack, or if it means it can be stretched to twice its length


    Dude George


    I've definitely brought my guns to and from Jamaica on several occasions lol. I've also brought them to St. Vincent and Barbados. They don't say anything. All i do is pull it apart and put it in a sports tube and says its fishing equipment

    Quote from gregaz

    Akira


    Dude George


    I've definitely brought my guns to and from Jamaica on several occasions lol. I've also brought them to St. Vincent and Barbados. They don't say anything. All i do is pull it apart and put it in a sports tube and says its fishing equipment


    Hahhahahahhahha I do the same, but I know I risk having everything seized, it has happened to my friends doing the same thing.

    A bad day at sea is better than a good day in the boatyard
    George Steele


    gregaz,


    It wont explode or anything. :D
    and it doesnt happen all at once.
    but this is my experience with the MVD Pro.




    this is after hundreds of shots with this gun.

    What am I not seeing Akira? How is it broken or bad? I'm not familiar with the mizzle. Im just trying to understand whats wrong in the pictures.Thanks.

    Quote from Hookinfish

    What am I not seeing Akira? How is it broken or bad? I'm not familiar with the mizzle. Im just trying to understand whats wrong in the pictures.Thanks.


    The ss wishbone elevators are bowed inward. They used to run parallel. with this, my shaft and shooting line upon exiting the muzzle began to chaffe resulting in my shots to go off.


    (They are made of what I assume is 316ss but are not very thick or reinforced by the muzzle itself.)


    I would have run the muzzle a bit longer, but after noticing this, I took the muzzle off and found a large crack in the spigot originating from the screw hole.


    (Delrin, in my experience is a very useful plastic, but it does tend to crack and chip more readily than composites like fiber/kevlar reinforced nylons, and even abs. I dont think it is an ideal plastic for muzzles. )

    After finding this i took it apart, saving the sheevs for a custom roller build;)

    LOL Akira, that's some serious damage on that muzzle. Is that the same one that Don Paul has in his pic?


    Because I have the 2nd generation one that they made after that initial muzzle. I get that it's still not as strong as the carbon ones like MannySub, but it should be able to take a better beating. Those little SS rails things on mine are thicker (it seems) than the one in the picture, and a lot lower (which is a little aannoying), but it should be stronger because of that.


    Would you be able to bend it back in shape, or is it a lost cause?

    Also, what kind of set up do you use on your rollergun?


    It is the spear with the large sharkfins where the line attachment is in the fin, or is it the one where the line attachment is in the back of the spear?


    I'm worried about attaching my line in the back of the spear because of how low the rails are on the muzzle. I feel like when the bands come to rest on the rails, and there's that little bit of spear left to pass through along with the line attached, it'll touch the wishbone and make the shot be inaccurate

    I was going to try to bend them back into shape, but when i noticed the crack in the spigot I scrapped it.


    Im using a southafrican style Torelli shaft with line tied to the back end. I had the same worries when i first started using rollers, and I used sharkfins (until i lost it in a hole to a knifejaw aka. living anchor)


    With sharkfins i think it is important to load the bands to the last sharkfin behind the line loop (especially if they are higher profile) that way it doesnt hit or slice your wishbone.


    With notched shafts where the line is tied to the end i had no problems until the muzzles wishbone elevators started bending.


    I havent seen the new gen muzzles yet, but if they are like the new aimrite roller muzzles it should work fine. the elevators are low on these as well, but I haven't heard any problems yet. (just got one of these a few weeks ago,,,, I have yet to put it on a gun.

    Okay guys,


    Bad news. I went to the pool today and the rollergun was absolute trash. I did everything everyone said and when fired, it was about 6-7inches low on the target.


    At first I thought it might be the shooting line interfering with the shot, because the line attachment is in the back of the spear. So I cut off the line and shot the spear with no shooting line, and the same thing happened. WAYY LOW. I think it has something to do with how low the rails are on the new MVD muzzles. I definitely felt a little jerk when the spear was leaving the gun


    I didn't measure exactly how far from the target I was, but it was about 15ft or a little less.


    I used the 18mm bands with no pretension and then with about 20cm of pretension (probably more).


    I have no clue what's wrong. Anyone have any ideas? I'm going on vacation on Tuesday and I NEED this thing to shoot properly

    first off, no worries, youll find a way to slay some fish no matter your setup..
    second..
    If shooting reef fish... you probably wont be shooting from 15 ft away... most of my shots with my 120 are withing 10ft from spear tip to fish.


    to the problem...
    Is the muzzle you have made for the MAKO PP?
    MVD makes muzzles for specific models.


    Makos in my experience have a very high rail, if the muzzle was not made for a mako, the elevators may be too low.


    When the band is not loaded, does the shaft touch the wishbone when you insert it?







    id use 16mm rubber, much easier loading,
    if using 7mm shaft, 18mm rubber may be causing shaft whip


    post your exact current setup so we can figure it out.
    :thumbsup2:


    josh

    Hey Josh,


    Im using 18mm because someone recommended it :frustrated2:


    I have no problem loading it with a bunch of pretension. I'm an animal lol. I'll load anything when it comes down to it. I also made a load assist which makes it basically the same as loading a conventional looped band. I dont have enough time, or money, to order anything else. I just have to use what I have here


    I ordered the MVD muzzle on their site and they custom made it with the specs that I gave them. The elevators on the new model are just naturally a lot lower than the first model they came out with. But the shaft doesn't touch the wishbone when its not loaded. The shaft has about a 1/16" of wiggle room under the wishbone, and the mini sharkfins have just a hair.


    Shooting fish in Jamaica however, requires some serious range. The island is overfished and the fish are VERY weary of divers. Anything worth shooting is gonna be 12ft at the closest.. when you get lucky lol.


    I'm this close | | to just taking this muzzle off and going back to the old looped band setup. I've slain monster barracuda with it for many years

    Exact setup is as follows:


    120cm Mako Predator Pro
    7.5mm 160cm shaft (one regular flopper, one with a screw on break away tip)
    2 lengths of 18mm rubber 24" each for each side of the roller
    MVD custom muzzle
    Reel with 50m of line


    I tested pretension at 0, 22cm, and 30cm
    All the same results. A very low shot


    I saw this article online. But I'm definitely not gonna cut up my muzzle or rail on the barrel. I'd probably F it up anyways and just make it worst. The idea makes sense however, and I feel like this is why my shot is going low too. I just don't know how to fix it


    ROLLER UP: THE LOW TRAJECTORY SOLUTION


    Gregaz,


    very interesting article. Ive never pool tested my guns before. (just fish tested) :cool2: lol
    I wonder if this is happening with most roller setups?


    I am a tinkerer, with spearguns, polespears, fishing reels and rods, almost anything i can get my hands on.
    i like to make spearguns testing out new ideas and setups, rollers, enclosed tracks, tie on bands, etc....


    On a recent dive to a great spot, Me and my partner set out to slay some trophy Mu, Uku, and Ulua.
    I really wanted to try out a new carbon railgun I just put together, so i brought this gun instead of my trusty 100cm roller that i had been using for about a year.
    needless to say I got skunked this day, missing and ripping off nice fish, while my partner scored a nice uku and yellow spot trevally. 10+lbs (large for this somewhat rare spp. of trevally)


    On the drive home I asked him what he thought the problem was with my aim. He said basically "dont switch up your guns so much"
    He was using a 120cm wooden enclosed track (KAP euro) He said he hated it at first because he would miss alot of fish and the aiming wasnt as clear as his railgun. But, as he practiced with it he learned to aim instinctively more so than down the shaft. (Hes a bad ass, and gets head shots on 99% of the fish he shoots at)


    Moral of the story, for now stick with the gun and setup you are used to, maybe save the roller for later when your'e used to shooting it or for a more chill dive situation.


    Goodluck
    and have a good trip!
    Dive safe,


    Josh


    Gregaz,


    this is a (not so great) image of my 100cm roller setup.
    This uses 16mm rubber at around 50cm. pretensioned to the clevis pin back at the handle. when loaded it is stretched 4x its original length. Its reasonably easy to load, with lots of power and good range.


    Josh

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