BB stuck in bucking lips

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madmogga

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Just after a bit of advice  as i can not find an answer, i have just got myself a new MAXX CNC hop up for my ICS DMR and in testing noticed that the bbs when pushed forward with the nozzle stay in the lips of the bucking, silly question but is that correct or should it be pushed all the way in ? ive just never noticed this before 

 
The BB will get pushed inside of the bucking lips, just in front of the backspin 'mound'.

The nozzle should penetrate the bucking lips to create an air seal with the barrel.

Is that what is happening?

 
That’s for the reply no thats not what’s happening

what happens is the nozzle pushes the B.B. into the lips but not all the way through still seams to fire ok and get a very good air seal with the new hop my fps increase from 335 to 365 i just think that maybe the new hop unit it to right around the bucking but did not know if I should take something off the lips or hop unit or just leave it

 
Are you cycling the tappet plate / nozzle manually to check that?

 
Yep it’s an ics split gearbox so took the top out along with the barrle pushed them together pulling back tappet plate then letting the spring move it forward also checked to make sure nozzle moves all the way forward ok 

 
So with the tappet plate fully home in the gearbox upper (I.e. Tappet spring is at rest) the nozzle does not penetrate the bucking lips?

Post I pic if you can

 
No one he nozzle seals nicely but the B.B. just dosenot get pushed all the way through I’ll post a pick in morning thanks for the help

 
If the nozzle penetrates the bucking lips then the BB obv gets pushed inside.

 
Drop a BB down the feed nozzle. It should then take a very light pressure to push the BB past the hop rubber lip. The Maxx Hop is tightly toleranced and doesn't work with 'fat' hop rubbers. It works fine with Maple Leaf rubbers. Also, did you need to force the barrel in the get the clip to seat properly?

 
Thanks for the advice I was using a flat hop bucking so swapped for maple leaf B.B. goes into bucking correctly now shame about the flat hop as this is why I got the maxx hop unit 

 
R hop it, and use the Maple leaf with the mound removed. The aluminium nub tends to tear flat hops.

 
Let me qualify what I just said a bit. The Maxx is a bit of a waste with a standard hop rubber and nub, as it doesn't offer any real advantages over a much cheaper unit. It's strength lies in the fact that it's a true TDC hop unit, and it's especially good at applying a very even and consistent pressure over the length of a R hop. This does apply to Flat hops as well, but the aluminium concave nub just slices through the hop rubber, although you get most of the advantage if you use a soft flat nub.

But with a R hop it excels at applying an amazingly consistent hop with very little pressure, even with heavy BBs.

 
Ok thanks I have a dmr build which I was going to put the maxx hop into which has been r hopped but thought I’d try it on my aeg to iron out any issues sound like a plan to flat hop the maple leaf bucking and use it on my r hop 

 
Mine lives on my DMR, but I've nicked the TDC principle for my AEG.

Works a treat.

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Looks good so it’s in my dmr and have another issue now running .32 B.B.s it worked great consistent 355 fps with about 2fps difference however when I switched to .2 just to check it’s under my site 450fps the fps keeps dropping started at 442 then each shot I watched it go down to 300 fps I popped in the .32s again and had stable fps is thier any reason an r hop dose not like .2 bbs

 
Thanks for all the help - so what i did was firstly put my Maxx unit into my DMR which is r-hopped this had a Prometheus soft black straight bucking, on testing with ,32 geoffs the seal was good and got a nice consistent FPS which is what I was after - however when i pushed .20 BB;s through i got all sorts of different FPS readings even when i turned the hop back down. so as advised by hangtight i flat hopped a maple leaf 60o bucking and popped that in, and the issue with the fps drop on .2 bbs has now all but gone. i still do not think the air seal is as good as it can get as every 10 / 15  shots i am still getting on large drop in fps from say 440 with .2's down to about 250 - i think this is to do with the metal ICS nozzle the end of the nozzle is very flat  so i do not think with the tight tolerances of the Maxx unit it is able the easy seal inside the bucking lips every time, So i have now ordered just to see the MAXX 21mm Double o RIng Nozzle and also Cylinder head to see if that solves the problem this nozzle appears to have a good taper at the end so should push inside the bucking lipps correctly. 

Anyone used their nozzles with the Maxx hop unit ?

ive not yet been able to get out and test the range and accuracy of my new DMR past the 25mtr target shooting in my back garden so hoping once i have this air seal problem sorted it will perform well in my first skirmish which is booked for 3 weeks time 

 
You've probably hit the nail on the head with the ICS nozzle, their flat ended nozzles rely on making a perfect 'butt' seal, e.g. face to face.

Pretty much all other nozzles have a taper and sit inside and expand the bucking lips which gives a much more consistent seal

 
Well the new nozzle and cylinder head arrives today so ill try it out and let you know how it works.

 
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