Masamune 6.01

[axisofoil]

Alright guys.
First impressions:
It's heavy and polished to a mirror finish. It weights about 1.5x as much as the prometheus it's being tested against. The crown is neatly cut and very deep, almost 2x as deep as the prometheus. The hopup cutout is tapered nicely from outside to inside... this should allow my bucking to flex more naturally and will probably increase life of buckings significantly. It came in a rigid plastic tube about 2x the diameter of the barrel. There was no machining oil or shavings or dirt inside the barrel whatsoever, and it looks to be polished internally as well as the prometheus.


I chronoed them with:


Chrono Results:
KA SR16 - Duracon piston head, sp130, spring guide, all that stuff. G&G bucking, h-nub, hop-up dial all the way off.
G&G .25g bb's, non-bio. 5 shots each barrel.

Prommy -  Average of 5 - 416.6, highest 418.0, lowest 415.8.
Masamune - Average of 5 - 423.6, highest 425.6, lowest 420.4.
Slight increase, nothing to write home about though. It seems to be slightly less consistent though.


50ft Accuracy Results:
20 shots each (G&G .25g non-bios, with a broken-in, but not worn out, G&G green bucking, fired after adjusting the hopup for a level flight. King Arms stock hop-up unit, fully upgraded gearbox for the velocity results listed above in 'chrono results'). Indoors, level shooting from a seated bench position with a bipod and supported pistol grip.

The airsoft GI 6.01 is notably better in that over 60% of the shots were within a 1" circle, and the overall spread was smaller by a fair margin. The Prometheus barrel showed a large number of shots in a 2" circle, with a fairly even distribution across it's overall spread.
Airsoft GI 6.01
1.75"x2.5" grouping


Prometheus 6.03
2.5"x3" grouping


Accuracy tests will come on a day when it isn't snowing!

[busta_cap]

I bought 2 of their VSR cut barrels to try out. They were cheap and looked ok. To say I was dissapointed would be a travesty of an understatement. Most barrels come with some dirt in them, hell even my pdi 6.01's weren't perfectly clean, but these barrels took me 20+ passes with alcohol with a felt rod to remove the dirt.

Even afterwards, the accuracy of the 550mm was worse than a standard 6.10 Tanaka aics barrel. Perhaps you will have some luck. IIRC they are just matrix re branded barrels. 509mm...Is that m16 length? With that length my suggestion would be to also focus on your hop up. Get yourself an SCS nub if you don't already have one, and then a good bucking like a firefly AEG.

Please be sure to post some groupings. If your gun is shooting 400ish, and with that length of barrel. I would try and do some 150ft tests. Most AEG engagements are under this. If you don't have that much room, I will be up at four peaks next week sometime and you can tag along. I do my long range testing out there(300+ft)

[axisofoil]

I bought 2 of their VSR cut barrels to try out. They were cheap and looked ok. To say I was dissapointed would be a travesty of an understatement. Most barrels come with some dirt in them, hell even my pdi 6.01's weren't perfectly clean, but these barrels took me 20+ passes with alcohol with a felt rod to remove the dirt.

Even afterwards, the accuracy of the 550mm was worse than a standard 6.10 Tanaka aics barrel. Perhaps you will have some luck. IIRC they are just matrix re branded barrels. 509mm...Is that m16 length? With that length my suggestion would be to also focus on your hop up. Get yourself an SCS nub if you don't already have one, and then a good bucking like a firefly AEG.

Please be sure to post some groupings. If your gun is shooting 400ish, and with that length of barrel. I would try and do some 150ft tests. Most AEG engagements are under this. If you don't have that much room, I will be up at four peaks next week sometime and you can tag along. I do my long range testing out there(300+ft)

Yes, 509 is M16 length.
I have an H-nub, I don't feel that using an SCS nub will give me any benefit over this. I use G&G buckings, they've been the best in terms of consistency that I've found so far. Is firefly making buckings that work with SCS now? I thought all of their buckings were designed to have the same effect (multi-point or constant gripping), but with a regular nub

The gun's shooting 500ish.
I found moving up from 509 to 550 or 650 didn't improve accuracy with the same type of barrels... (All I had in multiple lengths were CA 6.04's though... so it probably wasn't the most accurate of all tests)

I'm in prescott, I imagine that four peaks is slightly further than I want to drive for testing a barrel. I don't believe you've come to any of our games yet, but we definitely have 150-500 foot level, clear sight lines at certain places.

[busta_cap]

I bought 2 of their VSR cut barrels to try out. They were cheap and looked ok. To say I was dissapointed would be a travesty of an understatement. Most barrels come with some dirt in them, hell even my pdi 6.01's weren't perfectly clean, but these barrels took me 20+ passes with alcohol with a felt rod to remove the dirt.

Even afterwards, the accuracy of the 550mm was worse than a standard 6.10 Tanaka aics barrel. Perhaps you will have some luck. IIRC they are just matrix re branded barrels. 509mm...Is that m16 length? With that length my suggestion would be to also focus on your hop up. Get yourself an SCS nub if you don't already have one, and then a good bucking like a firefly AEG.

Please be sure to post some groupings. If your gun is shooting 400ish, and with that length of barrel. I would try and do some 150ft tests. Most AEG engagements are under this. If you don't have that much room, I will be up at four peaks next week sometime and you can tag along. I do my long range testing out there(300+ft)

Yes, 509 is M16 length.
I have an H-nub, I don't feel that using an SCS nub will give me any benefit over this. I use G&G buckings, they've been the best in terms of consistency that I've found so far. Is firefly making buckings that work with SCS now? I thought all of their buckings were designed to have the same effect (multi-point or constant gripping), but with a regular nub

The gun's shooting 500ish.
I found moving up from 509 to 550 or 650 didn't improve accuracy with the same type of barrels... (All I had in multiple lengths were CA 6.04's though... so it probably wasn't the most accurate of all tests)

I'm in prescott, I imagine that four peaks is slightly further than I want to drive for testing a barrel. I don't believe you've come to any of our games yet, but we definitely have 150-500 foot level, clear sight lines at certain places.

Yeah 500mm is probably about the sweet spot for your gearbox combo. Yould need to modify parts to match a longer barrel. That is the great thing about HPA though.. The consistency without any suck back or less of expanding pressure.

[axisofoil]

]Yeah 500mm is probably about the sweet spot for your gearbox combo. Yould need to modify parts to match a longer barrel. That is the great thing about HPA though.. The consistency without any suck back or less of expanding pressure.

The small portion following is an unrelated to the thread comment about suckback. Please disregard if you're interested in the upcoming review (should be ready in a few days)

...suckback. right... you realize that the nozzle is disconnected before the piston begins traveling backwards? or that any vented piston head doesn't seal as well while moving backwards? and that the most suckback you could possibly attain at that point is the pressure equalizing to atmospheric? which would actually help your accuracy and consistency by eliminating blowby (air traveling out of the barrel behind the bb, usually turbulent and therefore unpredictable, and therefore inconsistent?)  Just a thought.  

The longer barrels didn't help, but they didn't hurt either. They were just longer. I'd much rather have the same performance in a shorter package. And I couldn't honestly see a longer barrel being necessary to stabilize the round. Even without any chance of suckback or anything like that. If it made that much of a difference to have longer barrels without suckback, you would see ported barrels much more often. Paintball barrels are ported for the opposite reason, to prevent blowby caused by an HPA/CO2 system putting too much gas into the barrel, but would serve the purpose of also eliminating the Unicorn we call suckback if it's such a big deal. Maybe someone with a few VSR barrels should give it a test.

If you'd like to have the suckback argument, I'm more than willing to stand my ground until you can prove to me that I'm wrong, or at least make a logically sound reason that I'm not necessarily right. BUT, this isn't the thread for it.



Anyways, back to the tests... I'll run them at 150 and 200 feet... maybe more or less depending on the conditions the day I go out to test.

[Vince]

No, you're wrong - I can't express it mathematically at the moment, but empirical evidence across years of research shows that suckback is a definite phenomenon and the main reason you need to match cylinder volume with barrel volume. If suckback didn't happen, there'd be no need for ported cylinders, sealed cylinders, etc.

[axisofoil]

No, you're wrong - I can't express it mathematically at the moment, but empirical evidence across years of research shows that suckback is a definite phenomenon and the main reason you need to match cylinder volume with barrel volume. If suckback didn't happen, there'd be no need for ported cylinders, sealed cylinders, etc.

Ported cylinders are for blowby.
Matching them gives you the highest pressure for the highest amount of time before it reverts back to atmospheric pressure. That's the only reason it maximizes your velocity. If you go with too small of a cylinder, when there isn't the pressure gradient driving the bb anymore, it slows down dramatically with more barrel, it allows the bb to roll from the friction against the bottom of the barrel, thereby removing the effect of hopup and reducing range, and destroying accuracy if your barrel isn't perfect. Too much creates blowby, which hurts accuracy and precision.

Empirical evidence at one time showed that light is made of matter, and that matter doesn't exist. That's the funny thing about empirical evidence, you can explain it in many ways. Empirical evidence showed that the moon and sun moved across the sky, for example. Ancient civilizations thought that the Gods were dragging them around in Chariots.

If 'suckback' as it is commonly believed, occured, then if you used a ported cylinder with a 550 or so (something twice the volume of the cylinder), then the BB would return to the hopup instead of flying out of the barrel, assuming Air is incompressible. It would take even less barrel to create the effect taking into account that air is compressible.

PM me for further explanation of these concepts, or start a new thread or find an old one, and let me know. Once again, I would like it if this argument (I realize that that is all it's going to be) was kept separate from this thread.

[busta_cap]

No, you're wrong - I can't express it mathematically at the moment, but empirical evidence across years of research shows that suckback is a definite phenomenon and the main reason you need to match cylinder volume with barrel volume. If suckback didn't happen, there'd be no need for ported cylinders, sealed cylinders, etc.

Vince is correct, 100%. If suckback did not occur, the VSR freaks on ASR and ASF would not install air brakes and chop cylinders and such to match their barrel lengths.

[Vince]

axisofoil - making your text all small is really gay and you need to stop doing it.

When you have a certain barrel length and a certain rate of fire, the BB might not have left the barrel by the time the pistol has started it's cycle over again. When the piston draws rearward, it causes a vacuum, which, in turn, affects the BB. It doesn't suck the BB all the way back, obviously, but it is not hard to affect something that weighs a quarter of a gram.

The discussion about this started here and it will stay here - if the moderation sees fit to move it/split it, that will happen then.

Just concentrate on posting what you want to post and not what others are going to post.

[axisofoil]

axisofoil - making your text all small is really gay and you need to stop doing it.

I'll post relevant information in larger text, so that people looking for the information the thread was intended to be over can find it.

[Airsofter1]

This was a good discussion.  
Axisofoil, you're not helping yourself by posting that text so small.  
Lets end that part of it with agreeing to disagree.

You may continue with your review of the barrel.

[axisofoil]

This was a good discussion.  
Axisofoil, you're not helping yourself by posting that text so small.  
Lets end that part of it with agreeing to disagree.

You may continue with your review of the barrel.

Sounds good. I fixed the text size.

Barrel should be in today, I'll have the initial pictures and impressions soon.

viewtopic.php?f=5&t=26288
Also, for anyone wishing to continue the suckback disagreement/argument/yelling-match, I made a thread.


I'll have 50ft accuracy tests up today. Until it warms up, that's the best I can do.   I know that that's FAR too close to find anything other than extreme flaws in the barrel, and well within my MED... but it's the longest distance I have in my apartment to do this indoors with some semblance of safety.

50 ft results posted.