So... Does anyone know what happens when...

[NH Shooter]

You R-Hop a twist barrel? The science and simple enough... But in practice... Any ideas? Experience?

 

[Bullet]

My advice (and sorry to promote another forum) is to try the airsoft sniper forum there are lots of knowledgeable people on there. Make sure you read the rules first though. good luck!

 

[Unrustle_Thine_Jimmies]

Results have been inconclusive. Some people have reported very good gains while some have had complete disasters. By the way,the myth of the TK twist only working well at low FPS is a lie. You must have good cylinder - Barrel volume ratio (Read up on volume matching in AEGs) and a very good consistant air outuput for the TK twist to function well according to some techs. Most people trying it out didn't really share the info well too,lots of stuff was very vague.

I'd say bite the bullet and try it out if you are willing- Share the results & your set up in detail(Compression quality,cylinder used,hop up setup,etc..) so maybe we can finally get a conclusive result.

 

[BrightCandle]

None of the reviews I have seen of R hop have really shown the difference of just the R hop or different barrels they are used on and certainly not at the sort of FPS we typically use in the UK. The few reviews I have seen often show a default 6.08 barrel and basic bucking+nub compared to a tightbore with R hop, ie none isolated testing. When someone says an R hop is more consistent what I expected to hear was something like - "on 100 0.4g BB shots the 99% grouping was 12 inches at 200feet, but with the R hop that grouping was reduced to 7 inches". Good isolated testing of the high end options and how they are combined just doesn't exist as far as I know. Even in a lot of the tests where we see them comparing groupings there isn't a lot in it, the pattern is pretty wide and the variance is very high that its hard with the number of shots they took to draw any useful conclusions from the performance difference they are claiming. There is this guy in New York who did such a video with R hop and a tightbore at 60 yards and looking at the two sets of groupings there really isn't much in it. He would need hundreds of shots to determine if there was a difference, and due to the variable wind on the day and his own inaccuracy it was very hard to tell if there was an actual measurable difference.

There is one guy on youtube who did good comparisons of guns. He did them inside with the gun clamped. But he never tested upgrades, only the guns stock. I haven't seen anything from him in a year after he changed jobs so I think he has completely stopped now (despite updates on facebook saying he was going to continue). Ideally I want to see him with his highly isolated and scientific approach compare the upgrade options to determine the exact impact of these things individually and together. But right now I don't think there is a good test that I can refer you to that would show you the genuine isolated impact of the R hop or twisted barrel and certainly not one with them combined.

 

[NH Shooter]

Fair enough... I've got the barrel and as far as I know... Installed the rhop correctly. I've gone for a m nub in a lonex hop... As soon as I can get out to some range... I'll see if I can get it working.

I can't say as I can do anything conclusive... I just haven't got the time. But I can certainly give the differences in std vfc vs upgrades.

 

[BrightCandle]

Fair enough... I've got the barrel and as far as I know... Installed the rhop correctly. I've gone for a m nub in a lonex hop... As soon as I can get out to some range... I'll see if I can get it working.

I can't say as I can do anything conclusive... I just haven't got the time. But I can certainly give the differences in std vfc vs upgrades.

Click to shrink...

I think we can fairly conclusively say the upgraded kit is better than the stock most of the time, the evidence at least for that is relatively sound. Its comparing the various upgrades that is hard.

I haven't so far seen good conclusive proof that the R hop is better than the flat hop is better than a good bucking with nub. TM is widely considered the best hop up unit, and yet its a basic bucking and normal nub and achieves better performance than any other. We have to ask the question why that is and I haven't yet heard a good explanation, infact most reviewers just say its magic. You hear that a lot about TM hop up and yet there must be an important difference!!! It irritates me, there is a lot of magic claims and hand waving "this is better" and no tests.

The R hop video also kind of irritates me, they talk about testing and fixing it if its broken, but without showing what its capable of how do I know if its as reliable as it can be?! Makes no sense to me that I have to calibrate my work without knowing what the target grouping should be and what a bad R hop verses a good R hop grouping looks like.

 

[NH Shooter]

Yeah... It's all a lot of conjecture. Realistically, I needed to do side by side barrels, then side by side hops and all sorts... In a indoor range. With a slow motion camera, chrono and a regulated air supply... If only I had that sort of time!

I'll show you what I can though... If I suddenly start making 2 inch groupings at 150m, we'll know I've done something right...

 

[BrightCandle]

Just getting groupings is all we really need, FPS changed we can fix otherways (although its good to know if an R hop decreases or increases a little incase we are close to site limits). Ideally at least 30m range and do 100 rounds or so into a target from a clamp or a shooting stand so its nice and consistent and your accuracy is removed. Then we need to see pictures of the groupings produced. I guess because the R hop has to be made for a particular barrel we are stuck with a before and after, but you can presumably go stock -> barrel -> barrel + r hop which will be enough isolation of each factor to make some useful conclusions.

 

[NH Shooter]

I'm just looking into some stuff... Issue seems to be the tk barrel... The cfd is doing some really weird stuff with even tiny changes in variables.

I'll get some photo's up when I can get something decent. The cfd... I'll work on.

 

[Finius]

I used to have a twist barrel in my l85, never bothered with hop at all...