[Jacobarmstrong54321]

Hello! Im pretty new to the airsoft long range game. Im just looking for some different inner barrel widths that will be good for an upgrade in accuracy. I came across the “T-N.T. APS-X Inner Barrel System Kit H+”….
Apparently the barrel goes from a tight bore of about 6.02mm to a wide bore around 6.3mm….Has anyone had any experience with this type of barrel? Does it improve accuracy? Its an interesting concept and being a new member here I dont know if its been brought up before.

 

[SiliconeSword]

It has been around for a bit, but due to it's price there has not been any testing on here that I'm aware of.
I have seen a couple barrels like this such as EdGi, Grizzly, Baton, and more that I am forgetting, so there may be some truth to it, but I have yet to get one myself.

Down the road when I perfect one or two of my guns I will hopefully be doing cold and hard semi scientific tests on various hop and barrel things, but that will likely be in the not very exact future.

I'd go pop onto a couple FB groups that are sniper, DMR, and HPA related and I'd sound off on these barrels or ones like them there. You'll need to sort through some trash, but there are a lot more people to hear from there when it comes to things like this.

 

[nearsighted_ash]

Assuming you're talking about guns with a cylinder and a spring. Wide bore barrel (diameter > 6.1mm) generally requires more cylinder volume from you gun than usual to shoot at a functional fps, and by "functional" I mean enough to throw the BB at your desirable long range. So you either have to compensate with a shorter barrel/bigger cylinder or go with a gas gun. Guns with wide barrel would be considerably louder than the same gun with a tight barrel too since lots of air is escaping around the BB, thus there is much less resistance against the piston.

These problems are not applicable on a gas gun since they're generally overvolumed and doesn't produce piston slapping sound.

Regarding the accuracy, I'm not convinced that a wide bore barrel would have better accuracy than their tight counterpart both theoretically and practically, but you can try it out yourself to see what work best for your gun.

 

[SiliconeSword]

I saw a number of videos over the course of a few years from a Japanese guy who was trying to get maximum accuracy from his VSR-10, and he had his best results with a 6.10 barrel. He found that at 50m it had a better grouping than a Maple Leaf Crazy Jet, but at 10m the Crazy Jet had a better grouping than it. We are talking only .95J with .30g BBs, but
He did never get into lapping though, so his results may have been the same with a lapped Crazy Jet or other barrel as I'm pretty sure that you can get away with a worse surface on a wider barrel and still have okay results.

These things may vary quite a lot from gun to gun due to power source, and may even vary with BB weight, so it's mainly up to personal experimentation that will sadly cost some money.

 

[Doctor Jest]

I've got an Edgi dual bore (6.03 to 5.98) and a TNT barrel waiting to be dropped into a suitable V2 gearbox for testing. My initial trial was in a gearbox that had too little cylinder volume and it still performed admirably so in a setup with a more generous cylinder and further tweaks it should be acceptable. Anecdotally those barrels provide a more consistent terminal velocity but I haven't done exhaustive testing as yet and theoretically........who knows.

Watch this space.

 

[Leo Greer]

I have the TNT in 387mm. Paired with an ML MR.Hop 60 degree, DIY hard nub, and 3/4 cylinder, it performs very, very well. No scientific testing, just anecdotal as of yet, shooting different sized trees at 50-75 meters. The wind is my actual nemesis in getting real testing done on range and accuracy.

 

[Whamhammer]

So whats the principle with this barrel, the barrel stays a tight-bore until where the barrel is stabilized and the barrels bore gradually widening out, to have a less dramatic pressure change at the end of the barrel; sort of like a really gradual crown?

 

[RonSwanson]

I've been thinking about variable width inner barrels and can't seem to understand how they provide a benefit as the air pressure behind the BB must drop considerably as it widens and cause instability initially with a need to stabilise again at the lower speed.

So really a variable width is just causing the BB to prematurely slow in the barrel which is never ideal due to the limited space and more likely to ricochet of the sides?

 

[Leo Greer]

The end section is about an inch long on the TNT, and is quite rough--the idea being that it smooths the extra air out into a cushion around the BB. Not sure how much better than a normal high quality version of the same thing it is (I definitely don't recommend the TNT ones for how much they cost), but I do like mine. They're specifically designed for GBBs where extra gas is almost a given, but the idea holds for slightly overvolumed AEGs as well.

 

[Lightf4ng]

Edgi claims that dual bores that are short has little to no effect. His dual bore is a 50-50 ratio.

 

[Whamhammer]

I know that Miracle Barrels have a very long crown, is that somewhat similar to what is being discussed?

 

[Leo Greer]

Honestly, without direct comparisons of the same barrel with/without the weird expansion section… who’s to say what the exact effect is? I actually purchased the S+ to work with the TNT TR.Hop, and it was reported to be very high quality—the finish is very, very good.

 

[Doctor Jest]

Very similar in design to the old Tanio-Koba barrels but as Mr. Greer points out, employs a much shorter expanded/rifled section. I'm still waiting to fit mine into a build...

Not my picture: