The amazing R-hop test project!

[Cobrajr122]

I am excited to see the results of this.

I have a bag of Rhop patches that I ordered many months back that I have been FAR to lazy/busy to install, nor do I believe I have the skill to do it without spending some more time watching others do it.

Why not find a Polar star to use as a test bench for this? It would make the FPS changes quick and easy.

[ThunderCactus]

Because a polarstar isn't an AEG, they're closer related to GBBRs.
How a BB gets shot in an AEG is very different than how it acts in a gas gun

[Kos-Mos]

Originally Posted by ThunderCactus

Because a polarstar isn't an AEG, they're closer related to GBBRs.
How a BB gets shot in an AEG is very different than how it acts in a gas gun

This. And not.

The working principle is a LOT closer to an AEG, as there will always be a constant amount of gaz released, vs. GBBRs that literally wait for the BB to leave the barrel before cycling. It really acts closer to an AEG as there is a constant volume of air, but the pressure is instantaneous, unlike an AEG where the piston moving forward ramps-up the pressure... I say it's worth testing too.

I should have one up this summer, when that is the case, I might just "have" to test again...

[McKee]

The physics:

Hunterseeker, rhop creator, has his wobble theory.

http://forums.airsoftmechanics.com/i...p?topic=8507.0

If correct, it would explain how people manage to get 200ft+ ranges with less than 400FPS.

http://mackila.com/airsoft/atp/07-a-02.htm

ATP tells us sub-1.5 joules it should basically be impossible to reach 200' without hop lobbing or impractical elevation adjustment. Yet people continually report CRAZY ranges with R-hop on airsoft mechanics forum and elsewhere.

I'd love to see more results from our community, as well as anyone with a very good physics knowledge that could shed some insight into whether or not this is actually possible. I understand some flat hop mods increase range slightly, or are great for tightening up groupings (shredders, firefly, etc.) but I want to know if this extreme range is possible.

[Cobrajr122]

Originally Posted by Kos-Mos

This. And not.

The working principle is a LOT closer to an AEG, as there will always be a constant amount of gaz released, vs. GBBRs that literally wait for the BB to leave the barrel before cycling. It really acts closer to an AEG as there is a constant volume of air, but the pressure is instantaneous, unlike an AEG where the piston moving forward ramps-up the pressure... I say it's worth testing too.

I should have one up this summer, when that is the case, I might just "have" to test again...

Another point - HPA does not expand as propane/CO2 does - another likeness to AEGs.

So pretty much the only difference is like you said - the difference in how the air pressure is introduced to the BB.

If anybody becomes proficient at installing the patches though I'll be sending a barrel or few your way :P

[ThunderCactus]

The initial pressure is the thing making all the difference, that's what determines how much hop pressure you can apply. That's the specific and important detail that for this test means a polarstar is more closely related to a GBBR.
Yes we can test them on P*s and GBBRs, No we cannot compare an R-hop AEG to an R-hop P* or GBBR.

Originally Posted by McKee

http://mackila.com/airsoft/atp/07-a-02.htm

ATP tells us sub-1.5 joules it should basically be impossible to reach 200' without hop lobbing or impractical elevation adjustment. Yet people continually report CRAZY ranges with R-hop on airsoft mechanics forum and elsewhere.

We've been breaking 200ft with AEG's with out Rhop for a long time... and not by over-hopping either.
-All his testing was done with .25s
-Nobody getting out to 200+ft ever uses anything lighter than a .28

And furthermore, read the whole report, this is from his closing statements;

Are people really able to achieve ranges out to 300 feet?
In short, it is definitely possible to hit something at 300 feet.

Having worked through the problem in terms of theory and some testing using my own rifle, it is very possible to hit something at 300 feet and airsoft snipers are indeed achieving "kills" at that range and beyond. That being said, I'm still pessimistic in that I doubt that a shooter could routinely hit a target at that range. The longest range that I have achieved, observed, or have had verified for hitting at a 18" diameter target consistently is 235 feet

[lurkingknight]

I believe the common weight shot on ASM is a .3 or .32 I've even been told to use .34s and higher with 400fps guns... one was a p* user, a bunch more toting AEGs. The only issue is... who the hell makes those weights in a high quality round?

300' straight trajectory is suspect for me... I've seen videos of people shoot rhopped guns, but it doesn't look like 300 feet to me. None of them have a tape measure to measure it. What we need is a warehouse that's 300' long.

[McKee]

Originally Posted by ThunderCactus

We've been breaking 200ft with AEG's with out Rhop for a long time... and not by over-hopping either.
-All his testing was done with .25s
-Nobody getting out to 200+ft ever uses anything lighter than a .28

And furthermore, read the whole report, this is from his closing statements;

Yes but to further your quote and to put it in proper context, the remainder states:

If a shooter has a highly-upgraded rifle, he can extend his range out to 300 feet by aiming above the target. Take for example a shooter with a 3.35 J rifle firing at a target 300 feet away. Figure VIII-12 shows the trajectory of a 3.35 J shot using 0.36g BB's. In this case, the shooter would need to aim nearly seven feet above their target. Again, the rifle would have to be very consistent, and the shooter would probably need luck on their side, but it is definitely possible. (And... a 300' shot would be highly, highly unlikely with either a 0.20g or 0.25g BB.)

3.35J is 223% of the max field limits, equating to approximately 600FPS with .20g bbs. Note his claim of consistent 225' shots is based on those parameters. (where for him 'effective range' is something like an 8" drop, where max range is what is achievable with elevation and hop).



ATP has data based on multiple BB weights and several joule ratings, all of which falls within the same general model. However, the RHOP appears to break this model achieving very long effective range (flat trajectory) with conservative joule levels, prompting HS to produce his wobble theory.

Now I'm not saying that the ATP is irrefutable by any stretch, but until I see observations submitted to the same experimental controls as the ATP we have to assume it accurate. I am not convinced flat 200'+ shots are possible without a hot gun, over hop, aiming very high, or incorrectly judged range (or any combination of these). I have personally made 200' shots but they were a result of aiming very high above the target. There are, however, several claims with R-hop to be in excess of 200' with a flat trajectory AND remaining in the ~1.5J range. I would like to see these conditions documented and confirmed, and I hope if someone sits down to collect this data they can produce some reliable results.

[Wrath144]

I've been known to slightly overhop or underhop depending on the terrain, and adjusting my optic or simply point of aim to get desired range.
Before you ask, overhop in open terrain with long sightlines, underhop in bush so I can arc it over the bush and have it drop on my target.
I'll have probably quite a bit of data to contribute to this project. I have three of my own guns I plan on converting to IR-hop, as well as future customers guns.

[McKee]

https://www.youtube.com/watch?v=7jdFHuetXJg

This video in particular is crazy, and despite the amount of hop up chamber/nub/sleeve combinations I've tried over the years I've never even approached this.

I have an rhop z kit enroute and will be attempting the install. I have a 220' indoor range and will be attempting to document my ballistics as best possible to see if I can replicate the results.

Additionally, here is another interesting read: http://mackila.com/airsoft/atp/04-a-01.htm . Further just adds to the apparent magical abilities of rhop.

*Edit - As a side note, one of the major holes I feel in the ATP is this fact:

Originally Posted by atp

Hop-up as modeled throughout these pages should not be taken as gospel -- they're very close but not perfect. One thing that was not taken into account in modeling hop-up is the diminished muzzle velocity due the energy loss from the pellet striking the hop-up rubber. This was initially going to be part of the model, however I could not determine direct correlation between spin and energy loss, particularly so considering that different rubbers seemed to have different effects with no uniform consistency. At any rate, while energy dissipation, velocity loss, and other things have been tested and verified, the hop-up model is theoretical and should be used as a guide to understand the relationship between velocity, mass, and spin; trying to use the hop-up model plots to estimate how much you should aim above a target at 200 feet is beyond the current limits of the model and should only be used with a grain of salt.

It seems that the relationship between force placed on the hop-up by the standard style arm/nub unit vs the constant friction provided by r-hop may lie the secret to it's success.

[ThunderCactus]

What gun is he using? And what internals?

[lurkingknight]

Originally Posted by McKee

https://www.youtube.com/watch?v=7jdFHuetXJg

This video in particular is crazy, and despite the amount of hop up chamber/nub/sleeve combinations I've tried over the years I've never even approached this.

I have an rhop z kit enroute and will be attempting the install. I have a 220' indoor range and will be attempting to document my ballistics as best possible to see if I can replicate the results.

Additionally, here is another interesting read: http://mackila.com/airsoft/atp/04-a-01.htm . Further just adds to the apparent magical abilities of rhop.

*Edit - As a side note, one of the major holes I feel in the ATP is this fact:



It seems that the relationship between force placed on the hop-up by the standard style arm/nub unit vs the constant friction provided by r-hop may lie the secret to it's success.

That's pretty standard for rhop... mine has that kind of consistency.

I have shot my ir-hopped p90 on a measured range and hit 60m with every shot with no issues. The range stops at 60m and it is a slight incline up a slope. I could probably shoot farther but I lose sight of the BB.

TC: the gun is stock fps from vfc.. 340ish... he doesn't mention what weight he's shooting.

For my test I was probably using .28s @ 1.5J since they were feeding the best that day .

[Azathoth]

Originally Posted by McKee

https://www.youtube.com/watch?v=7jdFHuetXJg

I wish he was standing in front of the camera for all of that so you can determine if his muzzle is close to level to the target.

The P* gun I ran just this weekend with Rhop was hitting 130-150ft with zero adjustment on the dial. It was far too difficult to track BB's against the snow to see if I was getting ridiculous 200-300 ft ranges.

I am almost finished a ER hop, but In the test shooting and sanding it was shooting better than the R hop that I did that replaced my SCS setup from way back. IMO it's easier to upgrade a gun to 600+fps and shoot .43+ to get the same ranges as putting together a ER hopup YMMV.

R hop is a very inexpensive "upgrade" to a stock gun. however it's not a simple upgrade to get right like say the SCS system.

[Drakker]

Originally Posted by McKee

Now I'm not saying that the ATP is irrefutable by any stretch, but until I see observations submitted to the same experimental controls as the ATP we have to assume it accurate. I am not convinced flat 200'+ shots are possible without a hot gun, over hop, aiming very high, or incorrectly judged range (or any combination of these). I have personally made 200' shots but they were a result of aiming very high above the target. There are, however, several claims with R-hop to be in excess of 200' with a flat trajectory AND remaining in the ~1.5J range. I would like to see these conditions documented and confirmed, and I hope if someone sits down to collect this data they can produce some reliable results.

Long range shots with low power are definitely possible. I have a Cyma AK105, mostly stock, I downgraded the spring to a m90 (shoots 310-340 fps with 0.20g BBs, yeah, not very stable) and installed a Prometheus barrel and a Guarder clear sillicon rubber. Measured with a surveyor's tape, with 0.28g I get 62 meters (that's around 203 feet). My tests were done on a slightly windy day, due to the high fps variation, the spread is about 2.5 meters wide (8 feet).

My A&K spring SVD, fully upgraded with AirsoftPro piston and sear, Prometheus barrel and piston head, AirsoftPro hop up chamber and a PDI W-hop rubber shoots around 410fps with 0.20g BBs. The measured range is a bit longer at approximately 64-65 meters (210-213 feet) with 0.28g and 0.30g BBs. The spread is about 1 meter wide (3 feet) at that distance with slight wind.

This not only prove that 200 feet is doable at low power (~1 joule), but that increasing the FPS doesn't yield much of a range increase. I was shooting while standing, unsupported and with iron sights. I am sure that other players here have much better rifles than that, as that AK105 is mostly stock, and the A&K SVD isn't exactly the most accurate platform.

[ThunderCactus]

Originally Posted by Drakker

This not only prove that 200 feet is doable at low power (~1 joule), but that increasing the FPS doesn't yield much of a range increase. I was shooting while standing, unsupported and with iron sights. I am sure that other players here have much better rifles than that, as that AK105 is mostly stock, and the A&K SVD isn't exactly the most accurate platform.

Yeah. This.
I had a stock marui P90, put in a guarder clear and that was it, shot around 170ft, grouping wasn't too good, but it got them out there lol

Anyway this is really the bottom line of this test.
1) starting with already GOOD guns, that shoot far and accurate, and comparing THOSE against R-hop
2) having MULTIPLE people do the same test, to average out any differences in personal skill, personal bias, and extreme examples.

That second bit is really the most critical part. It's difficult to take any one person seriously, no matter how accurate they say their results are. Are they a good gunsmith to begin with? Did they match FPS to BB weight? Is the mechbox achieving maximum seal? Are they using a JG M4 or a marui M14 as a test bed? Did they install the R-hop properly?

So multiple makes and models of guns, already shooting what's considered to be "good", compared directly against itself with an R-hop.
Hopefully we get a broad enough range to make observations like R-hops work better in ___ style hop chamber, or on average most guns perform better, or maybe it doesn't make a big difference in an M14.

And as an added bonus, we'll also get some solid data on how AEG's are shooting! I really want to know the exact, exact numbers on my guns, especially my PTW lol
ahhhh I wanna go do some shooting now O_O