TM HK416 - Barrel and Hop Change

[Esoterick]

I'm looking at switching out the hop on my gun, keeping in mind the only thing I have taken apart is my pistols for cleaning so far.

The main reason for this is that whilst the gun fires pretty decently shots have a tendency to list to the right. What I'm now thinking is perhaps I should get a fancy barrel, although I'd only do that if the result would be the same or better than the stock one.

I followed through the video above and whilst I haven't tried it yet the take down of the receiver looks the same as on the SOPMOD.

The plan was then to replace the hop up rubber with this:

http://eagle6.co.uk/shop/catalog/product/view/id/262/s/firefly-hop-up-rubber-bucking-for-all-aeg-s-soft-black/

and replace the hop nub with this:

http://eagle6.co.uk/shop/catalog/product/view/id/533/s/firefly-flat-hop-tensioner-nub-normal-black/

Plus replace the barrel with this one:

http://eagle6.co.uk/shop/catalog/product/view/id/516/s/laylax-prometheus-6-03mm-eg-inner-barrel-275-5mm/

Basically I'd really appreciate it if anyone could let me know if this all sounds like it would work, or if there is anything I should do differently.

 

[jcheeseright]

that's pretty much the go-to setup for best performance where cost isn't really an issue. Fitting the firefly bits is a bit more complex than a normal nub/rubber combo though, the flat hop tensioner might need to be trimmed to fit the window in the barrel (sometimes they do, sometimes they don't) and when positioning the bucking you have to make sure that all 4 of the protruding 'ribs' inside the barrel are evenly spaced.

There's no dark art to it, just patience and a steady hand. As for cracking the receiver open, just punch the front pin, pull the charging handle and slide the whole upper receiver off. The rear pin is a dummy.

 

[Esoterick]

Thanks for the advice, I've ordered those parts accordingly

 

[BrightCandle]

Just be aware you can probably fix the drifting to the side with a reseat of your existing hop rubber. Its most likely not on quite straight, the barrels do have a tendency to shift sometimes and if they have rotated a little the window is slightly off and the rubber is applied in an inconsistent way. A flat nub reduces that tendency as can things like g/r hop rubber setups. The firefly bucking seems contrary to the ideal of having a nice big contact so you get consistent backspin applied with a larger contact patch (since its specifically using two separate contact patches). No idea how well that works in practice but I guess you will find out.

 

[Esoterick]

I think it's either shifted or has been damaged by me cleaning the barrel. Shortly after getting the gun I started using 0.25g BBs and the range seemed about the same, if not slightly less - basing range on being able to hit targets on the local site from fixed points. Still a little bit hard to say if it doesn't currently like 0.25g BBs as I would need an indoor range to say for sure.

Regardless I figure I may as well do some tinkering if I would have to pop the barrel and hop unit apart anyway.

 

[team flex]

Yeah, vids on YouTube will help. D it's quite easy, you will be able to do it. Please update on how it shoots with your upgrades as I am interested to see, cheers

 

[Lozart]

Please update on how it shoots with your upgrades as I am not erected to see, cheers

Is that really what you meant to say?

 

[team flex]

Is that really what you meant to say?

Oh ffs, this autocorrect is starting to piss me off. And yes it was autocorrect...

 

[Esoterick]

For anyone interested I replaced the parts on Saturday and went to a game on Sunday to test everything out.

Groupings on full auto are definitely tighter, although I wonder if the recoil jiggle effects this somewhat either way. I had read about hop rubbers needing bedding in and was planning on emptying my remaining 1-2000 0.2g BBs to do so but I arrived too late to do this. To my surprise I could set the hop just fine immediately.

The range is the same, if not very marginally greater - based on knowing my local site well and where I can and can't shoot to. I have no idea if the hop will get better with a bit more use, currently it is a bit better than stock and at least the drifting to the right has stopped. For the price it would be very debatable if it was worth it for most people, although I am glad I did it for the experience and even small improvements are nice.

One thing I would add is the HK416 has these little plastic spacers, which I found out about when one fell out as I separated the receiver. They are a bit of a pain in the arse to reseat(at least for a rookie) but they fit at the back of the upper receiver where it touches the gearbox/slots into the back of the lower receiver in front of the buffer tube. I'm probably not the only one that sighs when dismantling something, only for a part to fall out of who knows where

 

[jcheeseright]

Those plastic clips are a pain in the bum, they're there for a reason though, the 416 receiver is a tiny amount wider than the standard sopmod receiver and they help brace the gearbox.

 

[dex]

Its worth noting that theres little point in having a flat hop nub with a firefly bucking. These are designed to go into flat hop / r hop setups. Won't hurt it I'm sure, but not really necessary.