HPA issues

[KiloGr]

Hi guys,

Finished my HPA and was fine until i replaced the hop to the Maxx Pro hop.

Mags are very hard to get in and lock, and BBs shoot to the side (Right only) when shooting.

I have:

Rebuilt the hop 2 times

made sure inner not twisted

used different bucking and nub

aligned nozzle 

there is wear on the left side of the hop and the grooves on the outer barrel seem slightly twisted - i have come to believe the outer barrel is rotated slightly, causing the hop and therefore the inner to be rotated, causing them to hop right.

Any suggestions on how to fix this would be appreciated.

SPECS
P* JACK
ARP9 BODY + GB
MAPLE LEAF BUCKING AND NUB

MAXX PRO HOP

 

[Adolf Hamster]

Outer barrel being rotated would explain all those issues, although not why it was working fine before. I remember fighting that same issue with me old king arms barrel going onto an e&c reciever.

One of those situations where you might need to get creative with preventing the barrel from twisting on installation, or putting the time in to make sure its sitting square after the barrel nut is fully tightened.

 

[KiloGr]

Outer barrel being rotated would explain all those issues, although not why it was working fine before. I remember fighting that same issue with me old king arms barrel going onto an e&c reciever.

One of those situations where you might need to get creative with preventing the barrel from twisting on installation, or putting the time in to make sure its sitting square after the barrel nut is fully tightened.

Old hop had a longer spring, not sure if that would make a difference, will do some tinkering and testing.

If not, the grooves in the outer barrel, ill get dremmeld wider in the rotation it needs to sit, meaning it should sit flush?

 

[Adolf Hamster]

you do want a level of tightness for rotation, dremeling might make it loose so things like monopoding on the mag might rotate the hop in-game.

i'd look at the mounting of the outer barrel to the reciever, it's normally not an issue unless you start changing the frontend to the point of removing the barrel nut.

 

[KiloGr]

you do want a level of tightness for rotation, dremeling might make it loose so things like monopoding on the mag might rotate the hop in-game.

i'd look at the mounting of the outer barrel to the reciever, it's normally not an issue unless you start changing the frontend to the point of removing the barrel nut.

I took outer barrel out earlier and yeah its just the indents they slide into the upper with are twisted which sucks ass.  if i dremel out the grooves on the outer, i should be able to shim it up somehow so it doesnt rotate and stays straight?

Im sure my tech will figure something out, i dont want to finger it anymore and risk breaking something.

That and i dont have a dremel.

 

[KiloGr]

Outer barrel being rotated would explain all those issues, although not why it was working fine before. I remember fighting that same issue with me old king arms barrel going onto an e&c reciever.

One of those situations where you might need to get creative with preventing the barrel from twisting on installation, or putting the time in to make sure its sitting square after the barrel nut is fully tightened.

Just had a look at the old hop, didnt have the wings on the side, just a single slim unit.

 

[Adolf Hamster]

yeah it's one of those problems that can require a bit of fettling to solve sometimes.

iirc i ended up just having to tighten the barrel nut such that the barrel ended up square once it was tightened.

Just had a look at the old hop, didnt have the wings on the side, just a single slim unit.

the alignment tabs? it should do?