Best match for a JG / Galaxy MP5K hop rubber

[Rogerborg]

Bit of a long shot, but does anyone happen to know which aftermarket hop rubber is the best match in profile for the one in a standard Jing Gong MP5K hop unit like this one?

I ask because I've tried Maple Leaf, SHS and Lonex and none of them allow the barrel to push fully into the hop unit to the point where the clip can engage securely on it.  No PTFE tape or anything funny going on, it just will not push fully in.  This is with both the stock barrel and an aftermarket one, and with the stock hop unit in my Galaxy, and a Jing Gong that seems like an exact match (or rather, the Galaxy is cloned from it), so I have to assume that it's the hop rubber that's the odd factor out.

I've tried some bodging like slightly milling out the inside of one of the hop unit to allow the barrel and rubber to come further back, but then the lips get pinched and BBs will not enter - like, I literally can't even force them in, unless I move the barrel and rubber forward a fraction of a mm, then they feed fine, but I've got a poor air seal.

This just reinforces the lesson to leave stuff alone, but I am where I am with this unit.

Any suggestions as to what brand of rubber to try next?

 

[josh200025]

Have you tried the G&G green?

 

[Rogerborg]

Have you tried the G&G green?

Should I try the G&G green?

 

[josh200025]

I had the same problem with one of my guns, the prom my purple etc. wouldn't fit as the lip covered the the entrance of the chamber ever so slightly. The G&G green seemed to fixit for me, worth a try.

 

[Rogerborg]

Nice, thanks, I'll put it in the list of candidates.

To be super clear, I'm not getting feed issues from the hop rubber lips protruding into the hop unit. 

A Maple Leaf rubber actually works fine and got good feeding and air seal.  However it seems that there's to much thickness in what I've seen described as the "shoulder" of the rubber to let the barrel go far enough in so that the retention clip can engage and hold it securely in place.

View attachment 51554

 

[E21A]

?

i have a similar wonky chinese clone mp5 and I’ve got a maple leaf rubber in it that fits fine. Have you tried appliying silicon lubricant to the outside of the rubber before inserting (ooo err) into the hop unit. Maple leaf rubber are ribbed ( for her pleasure) on the outside and sometimes catch if fitment is tight. 

 

[Rogerborg]

i have a similar wonky chinese clone mp5 and I’ve got a maple leaf rubber in it that fits fine. Have you tried appliying silicon lubricant to the outside of the rubber before inserting (ooo err) into the hop unit. Maple leaf rubber are ribbed ( for her pleasure) on the outside and sometimes catch if fitment is tight. 

Yup, thanks, tried that, both spray lube and a dab of silicon grease.  It is a tight fit, but the rubber is as far in as it'll go and sitting properly on the barrel (it feeds fine) and no amount of pressure will get it or the barrel any further in.

The clip is in the right way round, I've checked the barrel(s), rubber(s) and the hop unit(s) for any imperfections.

I'll take it all apart again and give it another go, I'm just struggling to think of what else could be causing the issue other than the rubber profile.