[Hammar]

Hi gurus!

After reading through the forum a couple nights now (im back into 2009 posts) trying to wrap my head around ER-Hop setups and how they perform compared to stock well-tuned Hop-up buckings, i still havent found a "decent" explanation as to, how much further the GENERAL ER-hop modded rifles performs.

Knowing its a mod that is highly individual in how it performs on different setups i know there isn't any actuall numbers but i would like to hear from you guys who have ER-hops what kinds of distances you can reach out to effectivly.

I hear loads of you stay in the 350-420 fps range and given the heavier bullets used i tend to question the accuracy on real targets that are moving at 200ft+ due to the flight-time

Shooting on stationary targets is one thing but the flight-time of a bullet leaving the barrel at about 250-300 fps regardless of how straight it is, will still take a good long time to reach out to 250ft range.

So if you guys with experience with these mods could share your expert-comments on this i would be uber-happy!! :bow:

Hammar out.

 

[Cheese Man]

My ER-hops reach out to 100 meters easy. In game shots are not physically possible past 60-70 meters, so I hit out that far easy. Now I spend an average of 100 hours on each gun before I even fire it, so my rifles tend to perform pretty well.

Yeah, but the flight path is consistent enough that you just need to learn to lead the target. Bullet drop and all that stuff real snipers do? Now we get to use it.

True, but again, lead the target and it will hit them.

 

[MiloXC3]

It's FUCKING GOOD. blunt enough?

 

[defgun]

The difference between normal hop and R-hop in my A&K SVD was the difference between night and day. I used to be able to hit a man-sized target at about 100-120 feet, perhaps a bit further if I was being fancy about preparation.

Now, I can kick BBs out to past 250 feet with insane consistency. This is because R-hop not only provides more gradual and consistent spin, but it also centers the BB the same way for each shot. I can't recommend it enough. If you're not sure if you want R-hop, you want R-hop

 

[Hammar]

oh dont get me wrong, i've allready cut up my barrel so im on it!!

What i want is whatever numbers you can give me so i can have a refference as to how it performs compared to how it "should" perform once i get it out on the field for testing, you catch my drift?

so when you say you can reach out to over 100 meters -what muzzlespeed do you have with the BB-weight you're actually playing with?

and what's your take on bore up cylinders.

the setup im gunning for is M150 with 509mm barrel ERhop and ofcourse airsealing everything and custom-lathing the front of the nozzle.

 

[Cheese Man]

350-400 fps with a .2 bb, variable depending on how people are calling their hits. I use .3s - heaviest bb I can find in good quality.

I have never heavily modified a gearbox, so I have no clue.

Good plan, but what do you plan on lathing on the nozzle?

 

[Hammar]

thanks cheeseman, nice to get some numbers to wrap my head around hehe

Here's a kinda sketchy explanation of how i lathe my nozzles - dont seem to do much when you're in the 350-400fps mark but once you get up to about 5f00fps and above this REALLY helps with both consistancy and bb-placement between the rubber-lip and inner barrel.

first 2 pictures are of a standard nozzle and how it looks inside

Numbers correspond to the numbers on the image below.

1. flat surface against flat surface, creates non constant-wear and tear on the hopup rubber since it's flexing before snapping over to the 40 degree angled part of the nozzle.

2. Once the nozzle is pushed in as far as the actuall rubber will alow you're not really using all of the buckings available contact-surface-

3. Here is how i shape my nozzles, when the bb passes the buckings seal-ring the nozzle smoothly glides into the "chamber" and actually pushes the bb further into the barrel making it seated within the barrel rather than centered on the nozzle.

4. here is how it all looks when compressed, note the ammount of contact surface compared to the top view. AND last but not least, there's an actual STOP to the nozzle, creating a constant seal and constant BB-placement in the chamber every time =)

if we can find consistancy in the way every part moves every cykle i figure this must be one of the more important ones!!

This does (needless to say) require that the tappetplate is modded for extra travel into the rubber.

oh and btw it helps with feeding too, the radious on the nozzle doesn't dent or scratch the bb on it's way up, at least in theory -but hey we all wanna make the most of it dont we? =)

 

[vindicareassassin]

FYI there are some nozzles out there that are manufactured like this, I have a metal KN nozzle for 1 of my M14 variants that arrived shaped like this, it wasn't anything to do with me ordering it a special shape or anything, it just turned up like it from the supplier :shrug:


On another note I do something similar to this that doesn't require the use of a lathe, and also requires you to mod the tappet plate to go back farther.

It simply requires you to find an O ring that is small enough to go into the rubber lip unimpeaded, then just glue it to the nozzle tip, then apply a couple of coats of hard nail varnish to make sure its sealed at the joint..... jobs a good'un and no special tools involved so anyone can do it :tup:

Im liking the shoulder idea though, and the reason for it, might try and incorperate that into my next build :tup:

 

[Hammar]

hmm vindi, when gluing the o-ring to the nozzle and then coating it with nail-varnish that only helps with pushing the bb further into the bucking right? i cant see how it would aid in a better air-seal or in any way increasing the overall contact surface between nozzle and bucking. - i've heard about some canadian guy who did the same and i never really understood why, part from maybe pushing the BB further into the bucking/barrel thus centering the bb better when seated before a shot is taken.

Interesting to hear that some nozzles come with this shape -that means i must be doing something right hehe

oh and btw, it doesn't really require a lathe, a handheld drill, a steel rod that fits snug inside the nozzle, and a vice =) then you just use fine grit diamond files and do it by hand, works well if you polish the surface afterwards.

this is a mod for standard bore-nozzles - i havent tried it with bore up nozzles yet so it's gonna be interesting -less space to actuallly get a radious down so the tip of the nozzle slides into the bucking without flat surface hitting flat surface =)

 

[vindicareassassin]

Yep your right it pushes the bb farther in with the effect you describe, it also helps with the seal as it aids the rubber over the nozzle tip easier, similar to your design, it just doesn't have the nice abutment lip yours does, so more relies on the rubber being ramed tight into the little wedge you highlight,..... similar just not quite as effective :yup:


On a side note, it has long been accepted that slightly shorter flat fronted nozzles provide the best seal in full auto circles, and I've also read a thread on ASM where someone else did a similar design to yours, doing it using the same method you describe above, so yes it looks like your heading down the right track :tup:


We should realy take this back on topic now though and maybe start another thread for nozzle design :shrug:

 

[Hammar]

you are absolutely right my friend! Back on topic!

i can post this picture in a new thread instead because from what i've heard there's quite alot of fiddeling around with nozzleshapes =) -Good idea!

anyways, back to ER-hop.

I have cut the window on my barrel to appr. twice the length it had before, but i will update more about my rifle in specific in my project-thread instead.

What i want in this thread is just results, numbers and shared experience around ER-Hop in specific, sollutions to even pressure and so on.

 

[Cheese Man]

If you have uneven pressure you will not get good results. If you apply even pressure, it will fling bbs. As I have said many times, I use a TDC style system in most all of my rifles, as it gets the even pressure applied very nicely.

 

[Hammar]

first of all, the TDC style hopup doesn't seem to be any different from a double notched hopup with a concave hopup nub in some hard material that wont alow flex.. only difference is he is using a springloaded screw to make the adjustment - wich btw is what i will be doing - i will however be using 2 screws for dual-adjustment.

what i want to know more about is, as the thread name states, is the ER-Hop.

What's your sollutions to get a flat-pressure-surface on the patch? there's alot of threads where people say they have the ER-Hop but very few actually explain how THEY solved the whole elongating-part of the ER-Hop, both on barrel and hopup-house

 

[vindicareassassin]

I dont have an ER hop, per se', I make my own version of it.

Its basicaly an extended hop nub thats made from laminated plastic card, this is then fitted into an extended hop unit appeture with matching size window in the barrel.

Basicaly gives the same results via a different method.

A few pics of my long hop in my EMR with the V1 TDC adjuster for your perusal......

This is run in conjunction with an LRB and at 350 fps/.2 it will send a .4 out to around 75 to 80 meters with ease, add over hop and get used to the weird flight path and this can be extended well into the 90's

Im currently working on another AUG hop to go in my current project M14 Recce DMR that is similar but abit more advanced

I also do a version for the M4 style hop that still uses the standard gear adjusters, using the cam as its method of adjustment, with a lock screw and washer to prevent any movement, as yet no photos of it as its still very much a proto type.

I also have a version in my VSR that isn't very long due to the constraints of the length of the hop rubber

In all cases I've had best results from a flat nub, ie thats 1 with no profiles, concave or other wise.

 

[Hammar]

this looks basically like how i will be doing it, part from the fact that the adjusters will be in the hopup-house (m4 style) rather than threaded in the body.

i will not be using the standard adjuster either since i want dual adjustment =)

-i would like to see some pictures of he m4 version when it reaches the point of progress where you feel happy about sharing =)

Rock on and thanks for your input mate! this is like christmas for me -the techy stuff of DIY makes for a fuzzy feeling hehe op:

 

[sanguinor]

Vindi, if I understand what you've said & shown there correctly; you have extended and boxed out the hop arm part of the hop unit, then made a flat block that fits the area to push down onto your hob rubber with even force? Using the spring loaded screw to hold and adjust it?

 

[Cheese Man]

On the M4 style I drill and tap a hole through the upper receiver right through the top RIS. Basically, just measure to where your chamber is, and drill and tap there. I have my last AR packaged to send to Woogie, but he might be able to take some pics for ya.

 

[sanguinor]

Yeah, I'd like to see some more detailed photo's of that, it's something I would be interested in doing when I take my M14 up to an ER-hop.

 

[vindicareassassin]

Vindi, if I understand what you've said & shown there correctly; you have extended and boxed out the hop arm part of the hop unit, then made a flat block that fits the area to push down onto your hob rubber with even force? Using the spring loaded screw to hold and adjust it?

That is correct, that is version 1 of the system, I now use a dual screw system, 1 at front and 1 at back so that there is no, or limited, hop nub 'rock' as the bb passes underneath..... bit of an arse to set up but once you've figured out what 1 screw is doing from the other and the effect it generates, it comes togethre fairly quickly after that.

In my project gun Im building at the mo, that will be covered in my grail +1 guide, Im working on a slightly longer version of the 1 shown in the pictures, and this version showed much promise (despite having grease from the piston escape into it at the end of the day )

 

[sniperelite7]

For those of you who who use the ER-hop. How much flatter is the trajectory? With the r-hop on my gun for example. a .30g bb at 1.5j will have a flat trajectory out to around 180-190 ft. Beyond that naturally, I have to start holding over.