Sniper Rifles: Matching Cylinder/Barrel Volume

[EJ]

Hello everyone,

Let me preface my saying that if this has been posted in the wrong section, I do apologize. I looked at the other sections before posting, and this one seemed the most fitting.

I recently acquired a Tokyo Marui VSR-10 G-Spec and I plan to upgrade it very soon, and I've read that it is beneficial to match the cylinder/barrel volume ratio in order to maximize the efficiency of your sniper rifle. Another added benefit of doing this is that it will dampen the sound of the rifle when it is fired because there is little to no excess air leaving the muzzle after pulling the trigger.

I've read on numerous forums that the optimal barrel length for the G-Spec is 500mm, but what is the bore tightness when they state this? 6.03? And would a wider bore (say a 6.05) reduce the optimal barrel length? If so, by how much?

Furthermore, would the weight of the BB you shoot affect the optimal barrel length? Presumably it would require more air to push out a heavier BB, so it would make sense to use a shorter barrel when shooting a heavier round, would it not?

Any insight on this would be greatly appreciated.

Thank you,
EJ

[Hectic]

It is true that with a .20 the vsr10 (all of them) have a cyl. volume equal to about a 500mm inner.
dependant on what velocity you are running you will then run a heavier bb and itll sort of even itself out. If you are runing 450fps or less on a .20 .36 or lighter. 450-550fps yer runnin .36min more likely .43's
And with say a 400-455mm inner. Then you play with hop up and bbweights to find the best setup. If you plan on keeping a short barrel you could extend the port on tje cylinder

[ThunderCactus]

Speaking from experience, i used a 430mm laylax 6.03 with .30s on a pdi cylinder set and it was dead silent without an air brake.
id say thats the perfect cylinder to barrel ratio.

[EJ]

dependant on what velocity you are running you will then run a heavier bb and itll sort of even itself out. If you are runing 450fps or less on a .20 .36 or lighter.

Is this under the assumption that the shooter is utilizing a 6.03 tightbore barrel? I would like my rifle to be shooting around the 450FPS mark, but I want to invest in a PDI 6.05 430mm tightbore barrel, so would it be optimal to use slightly heavier BBs (like 0.40g) to better balance the ratio (since the bore tightness would be a modicum bigger)?

Speaking from experience, i used a 430mm laylax 6.03 with .30s on a pdi cylinder set and it was dead silent without an air brake.

Would it be obsolete to add an air brake (or to fill the stock with foam for that matter) if you've matched the volume ratios between these two components? I want the quietest sniper rifle possible, but I don't want to do more work than is necessary to achieve this goal.

Thank you,
EJ

[Hectic]

The silence would also be dependant on how heavy of a spring you run.
for me i run ~500fps a 455x6.01 inner a sobo pad no air break and the stock filled in with some veils (easy spot to keep em for different cammo in the field and helps to muffle the echo within the stock. Its not silent but outside of 50feet youd be hard pressed to hear it or at least pin point the direction.
Other way around. A bigger bore=more volume, so more volume wasted, so lighter ammo.
why are you wanting to go for a stock type bore? Most of the best barrels (read consistant, smooth bore) are 6.03 6.02 and 6.01.
Tho i will also piint out that 6.01x455 has a volume of 1307.82697mm3 and 6.05x455 is1325.29304mm3 so a wider bore wont make as much of an impact on volume matching as length, short barrel bigger cyl=more over/wasted air volume, so youll use a heavier ammo. But base velocity and ability to apply hop also have an effect. For example. No matter how short the barrel and big the cyl. If your gun shoots an m90 spring on .20's (~300fps) you wont be able to effectively shoot ammo much heavier than a .25 as the bb will just fly too slowly. its been prety well shown that in and around 300fps is the optimal velocity so if you have a 400 fps gun a .30 will give you ~330fps so thats close to optimal, .32's work well and for some (say rhoped or some other good hop mod) may be okay with .36's tho time to target will be a little longer and any gain in effective range or accuracy will likely be negated by folks bein able to matrix your shots lol

[EJ]

why are you wanting to go for a stock type bore? Most of the best barrels (read consistant, smooth bore) are 6.03 6.02 and 6.01.

I've heard that 6.01 barrels are superior when it comes to generating greater power, but they are not a good choice for long range engagements because there is less space for the BB to ride on a cushion of air from the hop up. Barrels with a wider bore produce a more consistent hop, which is paramount when it comes to sniping. Based on what I've read, (for long range engagements), the PDI 6.05 barrel is the best choice, which is why I'm considering investing in one.

Other way around. A bigger bore=more volume, so more volume wasted, so lighter ammo.

What you say here does make sense. With that in mind, would the following set-up match the ratios better?:

- 450FPS
- PDI 6.05 430mm tightbore barrel
- 0.30g - 0.36g BBs

Alternatively, what about this one?

- 450FPS
- PDI 6.01 303mm tightbore barrel
- 0.40g - 0.43g BBs

EJ

[ThunderCactus]

tighter bores are more prone to fouling. 6.01s are only for getting higher fps.
only use an air brake if you need it, and you do still need to fill the stock with foam.
And only use ONE barrel stabilizer. Your barrel is held between the hop chamber and the other stabilizer. Any more than that is a waste.

[Hectic]

Other way around. A bigger bore=more volume, so more volume wasted, so lighter ammo. Makes perfect sense if the barrel is wider it has a larger volume larger volume uses more air the to push the same bb, again as my math shows the impact is quite small goin from 6.01-6.05, but for arguments sake if a 6.01 performs great with a .30 the same gun with a 6.05 may run beter with .29 or .28bbs.
and 6.01 is good so long as you clean it regularly, 6.03 are also great and you dont have to clean as often. more importantly than the id is the consistancy of the bore. A high end 6.08 will out shoot a crappy 6.03 all day long.

[EJ]

Simply put, the quality of the barrel matters more than it's inner diameter and length, correct?

[Hectic]

Yes. Id is prety moot from 6.08-6.03. Length is important based on cyl volume and bb weight. But a good smooth even bore trumps all that for consistancy

[EJ]

On a slightly unrelated note (yet still relevant to this topic I think), what brand of BBs would you recommend using? Is there a particular brand of BB you would recommend for a certain weight range? Or is there a brand you would recommend across the board, regardless of what weight you choose to shoot? The reason I ask is because I've read a lot of mixed reviews about many brands, so it's difficult to decide.

Thank you,
EJ

[Hectic]

Bbbastard And madbull are good bb's. The elite force stuff is ok too.
bioshot or the above brands for bios.