Need some help with my hop

[LazzurusMan]

So, the other day I flat hopped my ares mutant, and on .25s I can get about 40 metres without lifting the barrel too much, 50 if I aim up.

I put .28s in it, and obviously I need to up the amount of hop. Then they start jamming, double feeding and almost falling out of the barrel. Is this down to too much hop?

 

[Rogerborg]

So we're all on the same page, what exactly did you do to flat hop it?

What bucking did you use?

What nub are you using?

What is it chronoing at with the hop off, with it hopped for 0.25g and 0.28g?

When you look down the hop unit and barrel while winding the hop from minimum to maximum, can you see the bucking pressing progressively into the barrel?  At minimum, is it only just visible?

And out of interest, why flat hop rather than throwing in a Maple Leaf bucking and omega nub?

I ask because I have done a successful pencil-eraser flat hop out of historical interest, but it's essentially pointless now that Maple Leaf is a thing.

 

[LazzurusMan]

So we're all on the same page, what exactly did you do to flat hop it?

What bucking did you use?

What nub are you using?

What is it chronoing at with the hop off, with it hopped for 0.25g and 0.28g?

When you look down the hop unit and barrel while winding the hop from minimum to maximum, can you see the bucking pressing progressively into the barrel?  At minimum, is it only just visible?

And out of interest, why flat hop rather than throwing in a Maple Leaf bucking and omega nub?

I ask because I have done a successful pencil-eraser flat hop out of historical interest, but it's essentially pointless now that Maple Leaf is a thing.

Click to shrink...

I used what I think is a guarder rubber. The nub is built in to my hop arm, and its similar to the omega nub from maple leaf. I flat hopped as I wanted to test and see if I could get more range and accuracy without spending more money as I have another spare rubber if this didnt work.

 

[Rogerborg]

The nub is built in to my hop arm

Click to shrink...

That just raises further questions.  Do you have a picture of this hop arm?

With a flat hop, you need a larger nub to press more of the bucking through barrel window.  Examples:

View attachment 90303

Or you can cut up a piece of pencil eraser or similar that just fits the barrel window.

I'll stop guessing now and wait for more info.

 

[LazzurusMan]

That just raises further questions.  Do you have a picture of this hop arm?

With a flat hop, you need a taller nub to press more of the bucking through barrel window.  Examples:

View attachment 90303

Or you can cut up a piece of pencil eraser or similar that just fits the barrel window.

I'll stop guessing now and wait for more info.

Click to shrink...

You caan just about see the hoip arm in this photo, and it's like its got an omega nub as part of the hop arm. I've checked the hop with the barrel in, and when I turn the hop up I can see the rubber pushing down into the hop chamber beautifully.

My issue is, when I try to hop .28s it's like the hop goes from not quite enouigh to too much with very little movement, and the bbs jam or just splutter out of the barrel. .25s I can get 40m, 50 if I counter the drop.

View attachment 90318

 

[Adolf Hamster]

looks like you're getting 4 issues:

1. flat hopped buckings in general have very sensitive "sweet spots"

2. the hard plastic nub shape combined with barely any material on the bucking is making it even more sensitive

3. that's not really the right shape for a flat hop (see 'borg's pictures above), the additional length of the nub is important as it increases contact length for the bb

4. you may well be running out of travel on the hop arm, flat hop nubs are thicker to account for the loss of material in the bucking and mitigate issue 2

your 2 solutions to this are either to revert back to a more conventional bucking, or change out the hop unit so you can use proper nubs.

 

[LazzurusMan]

looks like you're getting 4 issues:

1. flat hopped buckings in general have very sensitive "sweet spots"

2. the hard plastic nub shape combined with barely any material on the bucking is making it even more sensitive

3. that's not really the right shape for a flat hop (see 'borg's pictures above), the additional length of the nub is important as it increases contact length for the bb

4. you may well be running out of travel on the hop arm, flat hop nubs are thicker to account for the loss of material in the bucking and mitigate issue 2

your 2 solutions to this are either to revert back to a more conventional bucking, or change out the hop unit so you can use proper nubs.

Click to shrink...

Well the hop unit is proprietary to the rif, the one in that picture just shares the same hop arm but it's a different hop unit that screws into the outer barrel.

I don't get why the bbs would jam or just splutter out if the hop arm isn't pushing down enough. Honestly it's like theres too much hop. I had the same issue with the stock bucking, so I think I've got the first too issues you mentioned. It's got a very small sweet spot and I've gone over that point and need to very finely adjust back. Or just leave it and stick with .25s.

 

[Adolf Hamster]

Well the hop unit is proprietary to the rif, the one in that picture just shares the same hop arm but it's a different hop unit that screws into the outer barrel.

Click to shrink...

that'll be a tricky one then, best bet would be go back to a more conventional bucking unless you can find a more "standard" type arm that will fit that particular unit. i wouldn't suggest filing out that stock nub, it can be done but getting it to sit nice and square will be an absolute nightmare leading to shots curving off according to whatever way it's sitting.

you could try a maple leaf, the patch won't be held in it's ideal shape but i've done that before and it's worked ok-ish.

I don't get why the bbs would jam or just splutter out if the hop arm isn't pushing down enough. Honestly it's like theres too much hop. I had the same issue with the stock bucking, so I think I've got the first too issues you mentioned. It's got a very small sweet spot and I've gone over that point and need to very finely adjust back. Or just leave it and stick with .25s.

Click to shrink...

it could be you've got enough travel to get it to the jamming phase, remember you've gone from 2-3mm of "squishy" material to sub 1mm.

you might find it'll accentuate other issues, eg accuracy if it's very sensitive to velocity. i've had guns in the past where even the round count in the magazine was enough to trigger it's sensitivities.

 

[Rogerborg]

Oof, that'll go from too little to too much just by thinking of touching the wheel.

The last thing I'd do there is to use a flat bucking.  Maple Leaf all the way, get as much squish in there as you can.

The arm from a ZCI rotary hop might fit.  There's a spares kit available, although currently out of stock at AK2M4.  Or, have you tried throwing the hop from your G&G in there to see how close the fit is?  The flanges on the side of yours don't go as far forwards as on a ZCI V2 rotary, but files exist if the problem is too much material.

On that, you could try to file a notch into the arm's bell end to hold a nub.  There's not much there to work with, but with a small enough file and some precision and luck, an h-nub might be doable.

If that goes wrong, you could just flatten it off and cut up a rectangular pencil eraser nub, the traditional pairing with a flat bucking from circa 2005 Reddit.  I've done that with a ZCI rotary hop and it does work, hopping 0.28g just fine.  It's a gamble though, and pointless now that Maple Leafs exist.

 

[LazzurusMan]

Oof, that'll go from too little to too much just by thinking of touching the wheel.

The last thing I'd do there is to use a flat bucking.  Maple Leaf all the way, get as much squish in there as you can.

The arm from a ZCI rotary hop might fit.  There's a spares kit available, although currently out of stock at AK2M4.  Or, have you tried throwing the hop from your G&G in there to see how close the fit is?  The flanges on the side of yours don't go as far forwards as on a ZCI V2 rotary, but files exist if the problem is too much material.

On that, you could try to file a notch into the arm's bell end to hold a nub.  There's not much there to work with, but with a small enough file and some precision and luck, an h-nub might be doable.

If that goes wrong, you could just flatten it off and cut up a rectangular pencil eraser nub, the traditional pairing with a flat bucking from circa 2005 Reddit.  I've done that with a ZCI rotary hop and it does work, hopping 0.28g just fine.  It's a gamble though, and pointless now that Maple Leafs exist.

Click to shrink...

I can't fit any other hop unit in the mutant, it has it's own design, a little like the hop unit on an aug. I have heard of people using maple leaf bucking and nubs in a mutant by cutting and filing the hop arm to get an omega nub to fit.

I might do that in the future, but for now I can get enough range on .25s, and now I know why .28s don't work, the hop is just realy sensitive.