Tight bore and accuracy - a sea change?

[wally squad]

Well, I have always been of the assumption that the tighter the bore the more accurate the gun (and you also get the added bonus of 'free power'), so there I am about to get a tb for my gspec and having a little search around to see what to get when I find this on another forum -

 

 

From PDI

 

Actually,we are not sure to say 6.04mm is the best barrel.

Because it's depend on each setting.For example,if you want better

FPS,we recommend 6.01.If you want better accuracy,you may choice

6.08mm.

 

In our opinion,

In case of smaller Dia.,youfll get more speed.

On the other hand,in case of larger Dia.,youfll get abetter accuracy.

 

 

Smalller Dia. has strong pressure for BB.An Airflow makes BB stable.

 

 

Thanks

 

PDI Co.,Ltd.

Sales Manager

Tomohiko Nishizono

 

So I had a look at xfire/pdi site and this is how there advert for 6.08 barrels runs

 

High quality inner barrel.Its inner diameter is 6.08mm

 

This is new concep. Made of Stainless steel. It's not so tight,

This barrel keeps libration after trigger release low, and it rise up accuracy

 

So, anyone care to comment?

Yours, all of a fluster

d

[tome]

very interesting

 

I was always under the impression that the stock barrels were 6.08 because they could then be manufactured to looser tolereance withougt jams. A tight tolerance 6.08 precision made barrel improving accuracy?....... i suppose it's crazy enough to work!!!

 

we'll have to wait and see hehe.

[wally squad]

Just put an order in, so will let you know...

[DarkLite]

It's a load of cobblers.

 

Simply put, PDI are now unable to make their 6.01mm tightbores, or are unwilling, as installing one gives a very significant increase in velocity - a stock TM AK47 with a 6.01mm tightbore chronoed 349ish fps in one test I saw in a shop - and this, combined with the recent draconian measures that the Japanese Govt. has put into place regarding power levels, means PDI is no longer making 6.01mm barrels.

 

So, in order to sell something else, they put out a load of rubbish like the psuedo-technological testicular-metaphor above.

 

Get a stock TM AEG, put a 6.04mm in it and it'll be more accurate. Put a 6.01mm in it and it'll be a tack-driver.

[wally squad]

Could be lucky it's only a shipping price order

 

Questions questions

Why advertise a 6.08 as more accurate than a 6.01?

Surely they would be better off selling .01's as the accurate (and powerful) barrel and making three or four times the money - there will always be an export business.

 

I'm not defending here, and far be it from me to rock the status quo - just extremely curious

[greg]

Errr, actually I'm open minded on this & would love to try one & see.

 

Once upon a time every one was convinced that longer was better, but now, more & of us are seeing the light on that one.

 

I think it's about inner surface consistency & matching the right bb.

 

I wonder if 6.08 barrel with a 6.06 bb is possibly the same as 6.01 barrel with a 5.09 bb?

 

Food for thought.

 

 

Greg.

 

 

[tome]

That's along the lines i'm thinking.

 

Basically the stock barrel in an AEG is cheaply made and not consistent. To make a 6.04 barrel you'd have to have a finer manufacturing tolerance. (ie. if you had tolerance as loose as for the 6.08 in a 6.04 barrel you'll be more likely to get jamming). So replace a normal barrel with a precision made one, you'd naturally get better groupings....but is that solely to do with the reduction in inner diameter ;-P

 

Again for a 6.01 the consistency and tolerance has to be tighter still, resulting in a more consistent surface on the inside of the barrel.

 

So as far as i know no-one has made a 6.08 to tight tolerance and consistency yet so i'm keeping my mind open until we get the results

[greg]

Thank you, you put it better than I did.

 

It's not about diameter size, but the tolerance & the consistency throughout the length.

 

Then match that to an equally high standard, & appropriately sized bb.

 

 

Greg.

[scithe]

bah! i dont believe that for a moment. unless you have an H-hop there is nothing keeping the bb going perfectly straight while going down the barrel.

 

personally i think it is a marketing scheme... perhaps deescustom was such good competition that pdi's .01 barrels are not selling enough.

[Sale]

Well I've always said that quality matters more than the nominal bore. Take a Deep Fire 6.02 versus a KM Head 6.04 and I guarantee the KM Head will be more accurate. It's not just about the numbers.

 

Whether 6.08 would be more accurate, I'm a bit sceptical about that. I've found 6.03-6.05 to be a vast improvement over most regular barrels.

 

Then again, I have the stock TM inner barrel in my competition Glock, and after re-fitting the parts I'm making 50 mm groupings at 10 meters with that thing. TM inner barrels are known to be high quality, so at least we can agree that a good quality 6.08 mm barrel will be more accurate than a bad one.

 

-Sale

[wally squad]

How about this for reasoning - guess it's along the lines of a tk twist barrel...

 

The BB needs some space around it in the barrel to retain the spin given by the Hop-Up.

If we shorten this space between(what a tighbore does) the danger gets higher that the BB

looses this air-cushion(above and/or under the BB) and could loose an amount of the initial spin the HU has given,thats the tiniest part,

but if the space between is still more (extreme tighbores 6.01mm) the air-cushion could completely break and the BB would touch the

walls of the inner-barrel and could get a rocking motion...then not every shot has the same amount of HU-Spin given which resists in bad repeatability.

Borrowed from a n other forum.

 

cheers

d

 

[crimsonfalcon07]

That sounds all very well and good, but 6.01mm tightbore barrels ARE more accurate. I've proven that time and again shooting groupings. 6.01 is better than 6.03 is better than 6.08 in terms of groupings. This air cushion nonsense is just a bunch of hooey. It still makes contact with the walls in an 6.08. Do you HONESTLY believe that a bb traveling at high speeds is going to be unable to penetrate a measly little "air cushion"? Why do you think that 6.01mm barrels ARE more accurate. Just because PDI is trying this marketing ploy doesn't change years of evidence that tighter barrels are more accurate.

[wally squad]

That sounds all very well and good, but 6.01mm tightbore barrels ARE more accurate. I've proven that time and again shooting groupings. 6.01 is better than 6.03 is better than 6.08 in terms of groupings. This air cushion nonsense is just a bunch of hooey. It still makes contact with the walls in an 6.08. Do you HONESTLY believe that a bb traveling at high speeds is going to be unable to penetrate a measly little "air cushion"? Why do you think that 6.01mm barrels ARE more accurate. Just because PDI is trying this marketing ploy doesn't change years of evidence that tighter barrels are more accurate.

 

 

 

 

Not trying to defend , but I don't understand the marketing ploy really...why sell a cheap barrel as your high accuracy when most people who are chasing the ultimate will fork out big bucks for a 01, after all if you want more power a big spring is far cheaper than a $150 barrel.

The PDI guy seemed happy to reply to a mail, so perhaps he would furnish some evidence like groupings. Someone must be able to put together a test like... 2 rifles, same power/hop/bb's one running a 6.08pdi and one a 6.01pdi?

 

Just rambling really.

[DarkLite]

Not trying to defend , but I don't understand the marketing ploy really...why sell a cheap barrel as your high accuracy when most people who are chasing the ultimate will fork out big bucks for a 01, after all if you want more power a big spring is far cheaper than a $150 barrel.

The PDI guy seemed happy to reply to a mail, so perhaps he would furnish some evidence like groupings. Someone must be able to put together a test like... 2 rifles, same power/hop/bb's one running a 6.08pdi and one a 6.01pdi?

 

Just rambling really.

 

It's a load of cobblers.

 

Simply put, PDI are now unable to make their 6.01mm tightbores, or are unwilling, as installing one gives a very significant increase in velocity - a stock TM AK47 with a 6.01mm tightbore chronoed 349ish fps in one test I saw in a shop - and this, combined with the recent draconian measures that the Japanese Govt. has put into place regarding power levels, means PDI is no longer making 6.01mm barrels.

 

So, in order to sell something else, they put out a load of rubbish like the psuedo-technological testicular-metaphor above.

 

Get a stock TM AEG, put a 6.04mm in it and it'll be more accurate. Put a 6.01mm in it and it'll be a tack-driver.

 

It always warms my heart to see someone completely failing to read the thread before posting.

[wally squad]

It always warms my heart to see someone completely failing to read the thread before posting.

Sarcasm is cheap and easy, evidence is harder to come by.

 

The only reason I put the topic up in the first place is because I am curious - I believe the earth was considered flat once.

Until I see some evidence comparing like for like I will keep an open mind on the subject. I have invested plenty of money in tb barrels including pdi 6.01's so IF it transpires that a cheaper barrel is more accurate I will be somewhat annoyed too.

Anyway, have you considered that maybe the reason that TM settled on 6.08 barrels is that they tested various other sizes first....

 

Regards

d

 

[greg]

People are only skeptical because their experiences have taught them that the tighter barrels are more accurate.

 

That said, I've already posted my open minded view on this. The proof will be found.

 

 

Greg.

[wally squad]

Proof...You can't handle the proof!

 

[greg]

 

I've found lalax's 6.03 to be better than tn's 6.04, but I'm not sure this is necessarily down to bore size. It could be a tighter manufacturing tolerance, or the material, polished stainless vs teflon coated.

 

Who knows, but I find the lalax better.

 

If the 6.08 beats the 6.03 & is cheaper, great! Cheaper more accurate softers all round

 

 

Greg.

[Trasher]

Couple months ago we tested two upgraded (3 Joule) VSRs for groups. One w/ the 430mm Laylax stainless bbl, the other had the 300mm stock Marui barrel. Both guns produced about the same groups at 50 meters w/ .SGMs.

 

So much for the tighter barrel is more accurate.

[wally squad]

Couple months ago we tested two upgraded (3 Joule) VSRs for groups. One w/ the 430mm Laylax stainless bbl, the other had the 300mm stock Marui barrel. Both guns produced about the same groups at 50 meters w/ .SGMs.

 

So much for the tighter barrel is more accurate.

 

 

Empirical data, bless you sir!

 

 

 

 

[The Bushman]

I've only ever bothered to buy a tightbore once, many years ago, when they were first released. I stuck with stock barrels ever since and never complained, as I found no improvement. I only buy things, if I think they will provide value for money; tightbores are not in that category IMO.

 

I thought the G-SPEC had a 6.05mm barrel?

 

Many of my guns have had reported 6.05mm barrels (APS2 MK2, G-SPEC, m40a1) and I feel that accuracy is mainly due to HOP.

 

Besides I have always been a supporter of the shorter barrels and used to get put in my place by most folks on the subject. However, looks like the worm has turned?

 

Good Hunting

[DarkLite]

I found that on all of my guns, the accuracy increased immediately after installing tighter barrels.

 

I have seen it time and time again. A 6.04mm will give tighter groupings than a 6.08mm. A 6.03mm will give tighter groupings than a 6.04mm. A 6.01mm will give tight groupings than a 6.03mm.

[Trasher]

Empirical data, bless you sir!

 

Both VSR produced 7-8cm three shot groups w/ .29 SGM at 25 and 35 meters.

Both VSR produced 17-20cm groups at 50 meters.

My Atoz spring Dragunov is producing the same groups w/ the 590mm tightbore, and AEG-style hopup. (see my SVD accuracy test)

 

430mm Laylax bbl VSR is 560fps

300mm stock tm bbl VSR is 570 fps

590mm tightb bbl SVD is 560fps

 

Same BB.

Same BB batch/bag.

Same indoor range.

Same supported shooting position.

Same rangefinder, chrono, and caliper.

 

When it comes to accuracy, I think finding the best hopup setup, bucking, rubber sleeve, and BB for your airsoft gun, minimizing fps variance, flex/vibration/play is far more important than barrel inside diameter.

[greg]

Couple months ago we tested two upgraded (3 Joule) VSRs for groups. One w/ the 430mm Laylax stainless bbl, the other had the 300mm stock Marui barrel. Both guns produced about the same groups at 50 meters w/ .SGMs.

 

So much for the tighter barrel is more accurate.

 

 

& at 70m? (Which would seem a fairer test at 560fps)

 

As maybe the variation in accuracy may not have shown up until further out. 'Cos guess what, my mp7 gives the same groups as my vsr at 25m, but I know which one will get the 70m kill....................& so does everyone else!!

 

Do you think the +10 fps for the 303mm would have helped at all?

 

 

Greg.

[The Bushman]

DARKLITE: I have not invested the money on the subject to have the same hindsight as yourself. However, I will be fitting a new barrel in my tanaka soon, due to trialing the VSR hop conversion kit in my m40a1. The main reason for this is not the barrel, but rather the HOP rubbers.

 

If things tighten up, I will not be able to say how much of that is down to barrel bore or the hop system.

 

Few upgrades attract my attention and I am very easily pleased with performance. Yet this pax kit has got me interested enough to give it a whirl, as I suggested it could be good before it was invented

 

Despite your findings, its strange how TRASHER found no difference with the highly upgraded VSR using tighter longer barrel over the standard, carbine barrel using SGM's.

 

Good Hunting