Airsoft Canada - View Single Post - The amazing R-hop test project!

ThunderCactus · March 25th, 2013, 15:36

Stealth, agreed on all points!
300ft indoor range would be ideal, but outdoors will have to suffice.
Quick swapping identical barrel assemblies will make it easy to compare results in field, but taking the gun back and upgrading it to R-hop should produce the same test accuracy since you're using all the same parts you did before minus the mod. It just requires two tests.

The gun vice is an excellent point, I'll have to brace the gun against the side of my truck box or something while shooting to make sure there's no human element to inaccuracy!

At 500fps I'm worried there either won't be enough grip over the short patch, or the results will be too close without using some pricey extra heavy ammo.
At SOME point you do need to switch to an ER-hop, although I'd like to know what that point is, and how long the ER hop actually needs to be, I don't want to deal with that yet. At least not until we understand exactly what the R-hop actually does.

One argument I read was that the amount of time the BB is in contact with the hop patch is insignificant since the number is so small. I dismissed is as ignorant assumption since the man clearly did not grasp the scale of forces involved. Any way you look at it, the hop patch is DOUBLE the contact area. And if the BB goes from being in contact for .5ms to 1ms, that's still double the contact time. It obviously has to be doing something lol

Hunterseeker armories theorizes that it also reduces bounce in the barrel, allowing the BB to stabilize quicker. If that's true then we should also be able to shrink the ideal barrel length from 420 down to whatever. I've heard as low as 247 for AEGs, but in practice the magic number seems to be between 380 and 430mm. Between using heavier ammo and less bounce, perhaps that number could very well shrink to 247?

And I guess we'll find out if BB's really do have ideal relative velocities. It's been my experience that every weight of ammo like to sit around 320-350fps to get it's ideal flight stability. So now with the ability to add more hop to heavier ammo at lower speeds, maybe we'll find destabilization points where the BB just isn't going fast enough to maintain a straight path. Or that once the ideal backspin is reached FPS then equals range? Like if a 310fps gun can only send a .30 to 180ft without having that bump in the flightpath, and a 380fps gun can send it out to 260ft before having the hop hump.

It's exciting to work through this now, it's like the missing link of airsoft science!

Also we need a standard report model;
Make/model of AEG
barrel length
ROF
Brand of ammo used
test conditions (indoors, slight wind, etc)
distance verified by (tape measure, measuring wheel, rangefinder, shot at metal can, shot my buddy, videotaped on receiving end)

Standard hop ____ type rubber
fps on zero hop
fps at ideal hop
distance and spread with ____g BB
distance and spread with ____g BB
distance and spread with ____g BB

R or IR-hop
fps on zero hop
fps at ideal hop
distance and spread with ____g BB
distance and spread with ____g BB
distance and spread with ____g BB

March 25th, 2013, 15:36	#8
ThunderCactus Not Eye Safe, Pretty Boy Maximus on the field take his picture! Trader rating Join Date: Feb 2007	Stealth, agreed on all points! 300ft indoor range would be ideal, but outdoors will have to suffice. Quick swapping identical barrel assemblies will make it easy to compare results in field, but taking the gun back and upgrading it to R-hop should produce the same test accuracy since you're using all the same parts you did before minus the mod. It just requires two tests. The gun vice is an excellent point, I'll have to brace the gun against the side of my truck box or something while shooting to make sure there's no human element to inaccuracy! At 500fps I'm worried there either won't be enough grip over the short patch, or the results will be too close without using some pricey extra heavy ammo. At SOME point you do need to switch to an ER-hop, although I'd like to know what that point is, and how long the ER hop actually needs to be, I don't want to deal with that yet. At least not until we understand exactly what the R-hop actually does. One argument I read was that the amount of time the BB is in contact with the hop patch is insignificant since the number is so small. I dismissed is as ignorant assumption since the man clearly did not grasp the scale of forces involved. Any way you look at it, the hop patch is DOUBLE the contact area. And if the BB goes from being in contact for .5ms to 1ms, that's still double the contact time. It obviously has to be doing something lol Hunterseeker armories theorizes that it also reduces bounce in the barrel, allowing the BB to stabilize quicker. If that's true then we should also be able to shrink the ideal barrel length from 420 down to whatever. I've heard as low as 247 for AEGs, but in practice the magic number seems to be between 380 and 430mm. Between using heavier ammo and less bounce, perhaps that number could very well shrink to 247? And I guess we'll find out if BB's really do have ideal relative velocities. It's been my experience that every weight of ammo like to sit around 320-350fps to get it's ideal flight stability. So now with the ability to add more hop to heavier ammo at lower speeds, maybe we'll find destabilization points where the BB just isn't going fast enough to maintain a straight path. Or that once the ideal backspin is reached FPS then equals range? Like if a 310fps gun can only send a .30 to 180ft without having that bump in the flightpath, and a 380fps gun can send it out to 260ft before having the hop hump. It's exciting to work through this now, it's like the missing link of airsoft science! Also we need a standard report model; Make/model of AEG barrel length ROF Brand of ammo used test conditions (indoors, slight wind, etc) distance verified by (tape measure, measuring wheel, rangefinder, shot at metal can, shot my buddy, videotaped on receiving end) Standard hop ____ type rubber fps on zero hop fps at ideal hop distance and spread with ____g BB distance and spread with ____g BB distance and spread with ____g BB R or IR-hop fps on zero hop fps at ideal hop distance and spread with ____g BB distance and spread with ____g BB distance and spread with ____g BB Last edited by ThunderCactus; March 25th, 2013 at 15:57..