Barrel question

[Deerslayer]

Am I correct in my observation that the diameter marked on a barrel (e.g. .690, or .689, etc.) is the diameter only at the gun end of the barrel, and after a short section of this diameter, the barrel opens up? I've found any given paintball will be a touch fit at this end, but will easily drop into the muzzle end. This would make sense since the Freak system of barrel inserts consists of interchangeable tubes of different diameters that fit in a larger overall barrel.

Since the length of the known diameter is relatively short compared to the overall barrel, this section is what gives a gun the accuracy (or lack thereof) and the rest of the barrel is for acceleration of the ball in expanding air and quieting of the 'pop' through vent holes. True or false?

Why then do we see barrels of up to 16" long? At what point does the ball's acceleration transition to a constant velocity (and thus deacceleration due to drag)? Why are not most barrels cut off at this point? If the ball is rattling around in a long barrel that is not contributing to accuracy, what is the point to extra lenght?

[Psycho91]

8 inches is all that's needed, longer barrels are just for pointing/aiming and manipulating air bunkers in speedball, I prefer 12 in or shorter barrels but on pumps other then SC pumps I like 16 inch barrels

[iamthelazerviking]

Longer allows for more porting which allows for more quiet that's about it, in addition to the visual aspect of pointing

[Toestr]

On multi piece barrels the back is a control bore (the marked size) while the front opens up. You don't want to shoot paint from an overbore to an underbore because the air will rush around the ball then cause drag when it hits the underbore. It also risks paint breakage in the underbore part.

A one piece barrel should in theory be a consistent size for the length of the bore.

[BrickHaus]

The longer barrels have 2 advantages to me.

They offer a longer line of sight, so they are effectively easier to point and aim, but eventually you gain the muscle memory to hit the same accuracies on short barrels not offering the longer line

Where they really provide an advantage is on the speed ball field. A longer barrel allows you to push the side wall and shoot without having to expose as much of yourself.

[BrickHaus]

Also. Older one piece barrels were straight bore. A 12" lapco big shot is one true bore til the porting.

[RAZRBAKK]

I used to love rocking an 18" barrel to cut little peephole into the dorito.

[markdem]

Im sure i had a similar story to you, except my barrel tightened up in the middle (i think). I would roll a paintball through the barrel and it would catch in the middle. I also noticed i had more friction around the middle when i was cleaning the barrel. I think it may have been a manufacturing defect.

Im not going to go down the rabbit hole of barrel performance (you just opened a can of worms), i just wanted to say that you're not the only one to encounter this phenomenon

[Dusty Bottoms]

In terms of length, the major factor for 14in barrels becoming the defacto standard of paintball has everything to do with playing airball/speedball. 14in barrels allow you to tuck into inflatable bunkers, and still shoot, better than shorter barrels. Airball with inflatables became the main format of competitive paintball, so everything developed to cater to this format, and 14in became the proffered length. Before that change in the 90's, 8in, 10in and 12in barrels were far more popular than they are now.

[JeepDVLZ45]

8 inches is all that's needed

How’s bragging camp? 🤣😂

sorry, I’m a child

[Psycho91]

😂 I wish man I wish

[Psycho91]

I was wondering how long it was gonna take someone to make a funny out of that lol, yes I did it on purpose to

[Magmoormaster]

Oof ok

Per the best testing currently available, we know a few things:
#1 the length and bore size of a barrel DOES NOT affect accuracy
#2 the length and bore size of a barrel DOES affect efficiency

There are tons of variables, of course, but as a general rule, the optimum length of a one piece barrel is 12 inches. For a 2-piece barrel, it's 14 inches. Ideally, the length of the "control bore" (the back or a 2-piece, or the tighter part of a stepped barrel) is 8 to 10 inches, with an additional 4-6 inches of larger bore that's ported. So, the back is for acceleration, the front is for equalization and noise reduction. Anything longer or shorter than the optimum, and you'll see a reduction of velocity. It's minimal, but it's there.

I could go much much further in depth but for the same of brevity I'll leave it at that.

[MrBarraclough]

One piece barrels will tend more towards maintaining a single bore size down the length. Some barrels may be slightly larger right at the breach (gun end) than their nominal size due to chamfering at the lip in order to ensure smooth feeding of paint and avoid the bolt face catching on them. I suppose it is possible to see some enlargement near the muzzle end as well if the bore was honed with a tapered tool and the manufacturer honed it from each end.

As others have stated, two piece barrels tend to have a larger bore front piece/tip than the back. The obvious reason is to avoid creating a lip that the shell of the paintball might hit and fracture itself against when looking down the barrel from the breach end. For two piece barrels with multiple bore size backs available, the fronts are typically going to match or exceed whatever is the largest available bore size for the back.

False. Accuracy is not conferred by the size of the control bore.