Could the cocker shoot farther?!

[Jack & Coke]

Well at least you're making up for lost time... (21 posts so far in one day)

[CaliMagFan]

why sniper rifles are so.

lol you guys are looking for the reason that real guns use closed bolts to be more accrate thru the eyes of paintballers... and by the way... they dont use them to be more accurate... lol... the closed bolt design is to save energy.... if i'm firing a bullet, 1 bullet, with one chance to hit 1 target, i dont want to waste the energy that i have stored in the bullet's charge in the cartride out a breech... the reason: snipers shoot far, that is a given... they want to be able to get they bullet out there with every bit of the energy from their gunpowder as possible... semi auto rifles and handguns use the gas from previous shots to recock themselves in most cases... snipers dont need to put 10 bullets on a target, thats not the point...

so... the closed breech doesnt make a bullet fly any straighter-- lol--- it just makes sure there is no "blowback" or other means of lost energy, such as gas cocking mechanisms....

fyi blowback is governed by many atmospheric variables... so increasing the powder charge and making them open bolt would be ok.... the only problem is you dont know how much energy you will lose at a given shot.... so its just less consistent as far as muzzle velocity goes on guns...

you guys... so caught up in physics, missing the simple stuff sometimes...

the word of physics is based on common sense btw.....
-kyro

[Brophog]

The other reason that snipers use the closed bolt, bolt action is for silence.

It allows them to very quietly, and on their own terms remove a spent cartridge and load a new one. With a semi auto, it would re-chamber this cartridge automatically, which could give away the snipers position by either sound and/or visibility.

The real reason this argument is bunk is that almost none of you will actually take a single shot. Perhaps, in a single shot status, the closed bolt would be more stable, but how often are any of you going to shoot either an open bolt or closed bolt for one shot. Once you start shooting fast, both systems will behave very much the same.

Now, for me, I rely on single shots for a good portion of my eliminations. Do I feel that the closed bolt design is gaining me anything? I can't say I do. Its become one of those things to argue, just for the sake of argument.

[AGD]

HA! I even thought that closed bolt real guns were more accurate. Thanks Calimag your post made perfect sense!

The paintball has random spin orientation coming out of the barrel. The spin also varies between 0-3000 rpm.

You can make yourself feel better by thinking anything you want about how this gun is better than that gun but that doesn't change the facts.

AGD

[Doc Nickel]

Um, Tom? Haven't you ever spent time around any real firearms? CaliMagFan's explanation is (no offense Cal) complete nonsense.

The difference between closed and open bolt firearms has absolutely nothing to do with conserving muzzle energy; simply put, there's a hefty surplus of energy available when firing a cartridge- that is, after all, where the ear-splitting noise comes from: surplus energy not being used to drive the bullet.

Firearms use an open-bolt arrangement almost exclusively as a simplified full-auto mechanism.

In a closed-bolt full-auto, the bolt cycles, chambering a round, and once closed, a seperate hammer is released, striking a seperate firing pin to ignite the cartridge.

In an open-bolt, as the bolt closes, a fixed firing pin in the breechface ignites the cartridge. The bolt takes the place of the seperate hammer and firing pin. All the trigger mechanism has to have is a simple sear-catch not substantially different than that in any Spyder or old Tippmann SMG.

And as far as accuracy goes, what difference there is, is simply because the open-bolt is manufactured to "looser" tolerances (open bolt being used primarily in cheap/low-cost pistol-caliber submachine guns) and it has a typically huge (since the gun is a blowback) bolt slamming forward, which causes the shot to point low.

Again, none of that has anything to do with conservation of cartridge energy. There is far more energy available in the propellant than the bullet can use: much of it is directed back to the shooter as recoil, a great deal goes to make a bloody great lot of noise, and a nontrivial portion goes to heating up the barrel and the bullet itself.

Almost no firearm, save for perhaps the .22 short, allows all of its powder to burn before the bullet leaves the barrel- which is why, as far as firearms are concerned, a longer barrel provides greater velocity.

In short, there is far more than enough energy available to tap off a small portion to operate either a blowback or gas-operated semiautomatic mechanism.

There is essentially no analogue between open and closed bolt firearms, and open and closed bolt paintball guns, with the possible exception of the recoiling mass as it cycles. (IE, a bolt flying forward tends to drop the muzzle.)

And Brophog, "silence"? The noise of the loudest action in the world being cycled is nothing compared to it being fired.

You may have in mind the fact that some suppressed pistols are often fitted with a slide-locking mechanism, so the sound of the action cycling isn't a giveaway, but that sort of thing is intended for close-range work.

The reason "snipers" use a "closed bolt" is, well, because basically any weapon of a high enough quality (as in, anything not cheap stamped sheetmetal) to be used as a "sniper" rifle, and of a large enough caliber (any non-pistol caliber) to be effective at longer ranges, will basically by definition be a closed-bolt.

In other words, since there are so few "open bolt" rifle-caliber rifles as to approach zero, it stands to reason that "snipers" would use a closed-bolt.

The only open-bolt rifle-caliber arms I'm aware of are the M2 .50 cal and the old Browning BAR of WW2; both of which, while they have been pressed into occasional "sniper" type roles, are not by any means well-suited for the application.

Doc.

[Doc Nickel]

Originally posted by Y-Grip
Finally someone who knows what they are talking about. Also about the recoil/kick thing, it has been reduced because of LEVEL 10. The Superbolt II is the lightest bolt in paintball as of today.

Well, lightest 'Mag bolt, maybe. The 1-1/4" long, mostly-hollow aluminum bolt out of a PT Extreme is (at a guess) less than half the weight of an LX bolt.

If you want to count reciprocating mass, that's a different story, as the same PT would then have the hammer involved.

But even still, the all-Delrin, almost entirely hollow bolt out of, say, an '03 Shocker, is considerably lighter than the L-10 bolt.

Doc.

[bryceeden]

Originally posted by Y-Grip
Finally someone who knows what they are talking about. Also about the recoil/kick thing, it has been reduced because of LEVEL 10. The Superbolt II is the lightest bolt in paintball as of today.

And if you watch a newb with a mag that just had the LX put in they will very commonly say that the marker shoots farther, thats what got me interested in doing the tests on accuracy and range as a result of recoil.

[billmi]

Re: why sniper rifles are so.

Originally posted by CaliMagFan

so... the closed breech doesnt make a bullet fly any straighter-- lol--- it just makes sure there is no "blowback" or other means of lost energy, such as gas cocking mechanisms....

I don't quite understand what you meant by that.

Gas cocking mechanisms are used on closed bolt firearms. Gas from midway down the barrel is routed to the recocking piston that unlocks and opens the breech to chamber the next round.

See you on the field,
-Bill Mills

[AGD]

Doc,

Actually I a real firearm illiterate. I grew up hunting with everything BUT firearms (seemed to easy). Thanks for the info!

AGD

[Crighton]

Originally posted by Doc Nickel
The only open-bolt rifle-caliber arms I'm aware of are the M2 .50 cal and the old Browning BAR of WW2; both of which, while they have been pressed into occasional "sniper" type roles, are not by any means well-suited for the application.

Doc.

The original version of the Sturmgewehr 44 was the MkB-42 which fired from an open bolt. Of topic and all but an interesting factoid.

[BlackVCG]

One of the primary reasons that heavy machine guns like the M2, M60, M249, etc. operate from an open bolt position is to keep the next round from "cooking off" under heavy use, the barrel will get hot enough that if the cartridge is chambered, the heat in the barrel wall can preignite the powder and "cook off" the cartridge. Open bolt doesn't have a catridge waiting in the chamber so the cartridge is never in the barrel until it's being chambered to fire and then extract.

Closed bolt is used in sniper rifles and basic rifles simply because open bolt in a gun of that type would be utterly pointless.

[CaliMagFan]

man... thats the point....

edit: doc, i do take offfense to you calling what i said nonsenical... thanks btw

hey, that was the point of the firearms talk... i only use my knowledge of firearms use and some teardown... i think that DOC has a better grasp of the whole thing than i, as far as the facts. but doc, in the real world, when you're waiting to hit your target for at least a second after firing, dont tell me that gas escaping an open breach would have helped you hit it easier... i shoot these rifles, i know what 800+ yards to the target is like, an its the quest over control of variables that puts the closed bolt system into play in precision rifle shooting...

i think i'm in as far as i want to be in this quasi-paintball topic..

i think i'm going to design a sabot-shaped paintball and loading system tonight.--- wish me luck producing those projectiles... lol

-kyro

[Doc Nickel]

but doc, in the real world, when you're waiting to hit your target for at least a second after firing, dont tell me that gas escaping an open breach would have helped you hit it easier

You're right, gas escaping an open breech doesn't help you hit the target "easier".

But it doesn't make it "harder" either. And, like paintball guns, what the gun does after the projectile has left the barrel has absolutely no effect on where or how far the projectile goes. Once the bullet has left the barrel, the gun can shake, rattle, roll, cycle, slam or wobble all it wants and it can't affect the bullet even if it is flying for a full second.

In your first post, the one I was replying to, you said:

[T]he closed bolt design is to save energy[.]

And that's not the case, at least in the way you're implying.

The bolt is closed because that's the whole purpose of the bolt- to close the breech and seal it to prevent the loss of propellant gasses.

It doesn't matter where it starts from, open or closed, ALL firearms fire from a closed, sealed breech. (Just as ALL paintball guns fire with the bolt closed or breech sealed.)

You follow that with:

if i'm firing a bullet, 1 bullet, with one chance to hit 1 target, i dont want to waste the energy that i have stored in the bullet's charge in the cartride out a breech

Again, there's far more energy in a cartridge than the bullet uses; I believe less than half of the propellants' potential energy actually goes to drive the bullet. Some powder will actually leave the barrel unburned. (When the M-16 was first issued, the Army changed the propellant spec- the new ammo gave a higher velocity, but fouled the guns' gas system and bolt head with unburned powder granules.)

What you're looking for is not raw power (IE, extracting every last bit of energy to create the most projectile velocity) rather, you're looking for maximum consistency- IE, putting the bullet in the same spot, at the same velocity, every time. What we call "accuracy".

"Power" is irrelevant. As far as target shooting is concerned, most rifles will impart enough velocity to the bullet so that it will still penetrate a paper target even at 800 or a thousand yards. Power is meaningless- accuracy is the important part.

Even for "wet work" (a "sniper" shooting a person or a hunter shooting an animal) most medium and larger caliber rifles will still hold more than enough energy even at extended ranges to be lethal.

With the surplus of energy used to fire the projectile (again, all that noise, smoke and barrel-heating, is basically waste or surplus energy) the tiny bit tapped off to operate a semiautomatic mechanism (whether it's recoil-operated or gas-operated) is statistically insignificant.

In fact, you can check it yourself. Borrow an M1 Garand or M1-A, and chronograph the same load both normally (semiauto) and with the gas system shut off (both rifles have a provision for doing so.)

You may very well see a slight increase in velocity, but again, the key here is not the velocity itself, it's the consistency of that velocity. As long as the action uses the same amount of energy for each shot, your consistency remains the same, and thus maintaining your accuracy.

Continuing:

an its the quest over control of variables that puts the closed bolt system into play in precision rifle shooting[.]

And my point is that you're talking essentially nonsense. First off, no one shoots an "open bolt" rifle in any sort of target competition, and that comes from the simple fact there are no open-bolt target rifles.

There's damned few open-bolt rifles, period, and all of those, as noted earlier, are one form or another of machine gun.

You stated at least twice:

it just makes sure there is no "blowback" or other means of lost energy, such as gas cocking mechanisms....

they want to be able to get they bullet out there with every bit of the energy from their gunpowder as possible.

... That the primary reason for a "closed bolt" is to put the maximum amount of energy in a bullet, particularly at extended ranges.

And that's not necessarily the case. Yes, the cartridge needs to be fully sealed to the breech to prevent gas leakage, but again, ALL guns fire when the breech is closed, so the distinction is pointless and irrelevant.

i think i'm going to design a sabot-shaped paintball and loading system tonight.--- wish me luck producing those projectiles... lol

It's been done: machined teflon sabots to fit a paintball to a "Paradox" rifled shotgun barrel (and fired with a Nelson valve, as I recall.)

I didn't see it myself, only heard of it second hand, but the bottom line was that there was no improvement in accuracy.

If you're going for maximum velocity the sabot system might have some use, but naturally, you can't play a game at anything above 300 fps. Still might be interesting to see how fast you can push a ball before it explodes in flight like a .17 Fireball.

Doc.

[moballs]

nerobro and FallnAngel are defently correct in that paintballs dont act as bullets do The reason rifleing helps real snipers is because spinning the cone shaped bullet keeps areas of unequal pressures from building up on different sides of the bullet (similer to vortex shedding on a sphere) the reason snipers use single shot closed bolt action is because it holds more psi behind the bullet while in the barrel.
oh yea when a paintball spins the shell does most of the spinning because the Polyethelyne glycol is, of course, a liquid in side the hard gellatin shell

[No sKiLLz]

Um. I thought we were talking about paintball?

Can the mag bolt even cause the paint to roll in the breech? The friction of the ball and the bottom of the breech would have to overcome the friction between the bolt and the ball, and since there is considerably more force on the ball from the bolt than from gravity, the bolt should win.