one piece better than two piece?

[AutomagBoy]

Wouldn't a one piece be more accurate than a 2 piece because the one peice fits the ball for the enitre barrel? Rather than a 2 piece fitting a ball for only 4 inches of the barrel?

[�.C.]

I have that exact same question in mind . . .

[FalconGuy016]

Id like to know too

[RRfireblade]

All else being equal,the length of the control bore has little to do with accuracy and everything to do with efficiency.

Jay.

[Miscue]

Nope... but one-piece is more gas efficient.

[MarkM]

Originally posted by Miscue
Nope... but one-piece is more gas efficient.

And this would be why? Two-piece doesn't mean great big hole between the two parts, given that Tom has stated that is the first ?? inches that make the difference....we are in general past that point in a two-piece design. So all the gas used to reach that point has been used so after the ?? point then efficiency is a mute point for a one or two piece. If you mean that due to the nature of two-piece barrels that tend to be of a much larger section after the control bore section then an inefficience may then show up. And since a one-piece barrel is again in general the same bore for the entire length (I know there are exceptions to this) then surely the drag factors would actually make this the most inefficient of the two designs. All this is not taking into consideration the step bore one-piece barrels that are made where different math would have to be done to find the result.

[nerobro]

I've never seen any "real" testing on the subject. But my guess is that a one peice will shoot more balls with less spin than a barrel with a two stage bore.

[magman007]

well you see, once the ball has reached its maximum velocity within the first few inches, the gas keeps it there throughout the barrel til hitting porting, once you hit that your gas escapes, also at porting in a single boare, the bore gets larger, creating your step bore.

[RRfireblade]

Originally posted by nerobro
But my guess is that a one peice will shoot more balls with less spin than a barrel with a two stage bore.

So you think the longer the ball skids down the length of the barrel the LESS chance of spin?

Interesting.

Jay.

[BlackVCG]

Originally posted by AGD

So as far as our guns are concerned, the best efficiency would be had with an 8-10" effective length barrel. Since two piece ported barrels with an effective length of about 5-6" are the rage right now you hear a lot of complaints about gas efficiency. Under some circumstances there is a good reason to use a short effective length barrel. Short barrels cut off the acceleration abruptly by venting and this has the effect of tightening up the shot to shot velocity variation. If you need this at the expense of efficiency then go ahead. Tighter velocity control usually translates into some improvement in accuracy due to better consistency.

AGD

[Miscue]

Originally posted by MarkM


And this would be why? Two-piece doesn't mean great big hole between the two parts, given that Tom has stated that is the first ?? inches that make the difference....we are in general past that point in a two-piece design. So all the gas used to reach that point has been used so after the ?? point then efficiency is a mute point for a one or two piece. If you mean that due to the nature of two-piece barrels that tend to be of a much larger section after the control bore section then an inefficience may then show up. And since a one-piece barrel is again in general the same bore for the entire length (I know there are exceptions to this) then surely the drag factors would actually make this the most inefficient of the two designs. All this is not taking into consideration the step bore one-piece barrels that are made where different math would have to be done to find the result.

Cuz I said so.

Two-piece barrels typically have 5-6 inch control bores... the tip is not "effective" barrel. One piece barrel has longer effective barrel length. Longer effective barrel allows more time for ball acceleration... Shorter barrel must use more air to increase acceleration rate to hit final velocity sooner. Increased barrel length results in dimishing returns, being optimal at around 8-10 inches. Acceleration rate of ball dwarfs negligible deceleration from both air and barrel coefficient of friction.

[RRfireblade]

Originally posted by Miscue


Cuz I said so.

Two-piece barrels typically have 5-6 inch control bores... the tip is not "effective" barrel. One piece barrel has longer effective barrel length. Longer effective barrel allows more time for ball acceleration... Shorter barrel must use more air to increase acceleration rate to hit final velocity sooner. Increased barrel length results in dimishing returns, being optimal at around 8-10 inches. Acceleration rate of ball dwarfs negligible deceleration from both air and barrel coefficient of friction.

That's very subjective,
with the exception of Lapco and some stock barrels(which are usually very large bore anyway)in most one peice barrels(assuming it's unstepped which basically makes it like a 2 piece)there is usually only 5-7 inches of unported length,basically equal to many 2 piece after which the friction has a negitve effect whereas a 2 peice stepped bore requires a similar acceleration but with out the added friction in the last portion.

Jay.

[joeyjoe367]

If it were up to me, I'd have a 1 pc CP barrel for every bore size, and every length. Maybe even every color, but hey, I'm dreaming right? I can want whatever i want

CP's have about 8" of unported barrel length (perfect a la AGD) making them pretty efficient.

[Miscue]

Originally posted by RRfireblade


That's very subjective,
with the exception of Lapco and some stock barrels(which are usually very large bore anyway)in most one peice barrels(assuming it's unstepped which basically makes it like a 2 piece)there is usually only 5-7 inches of unported length,basically equal to many 2 piece after which the friction has a negitve effect whereas a 2 peice stepped bore requires a similar acceleration but with out the added friction in the last portion.

Jay.

This is plain wrong.

Where the heck is everyone getting this silly idea on friction?

The friction DOES NOT MATTER... it's there, but it's a negligible force.

Barrel A: 5" effective
Barrel B: 9" effective

Situation: Use same exact volume/psi of air using both barrels. The velocity of a ball in barrel A and barrel B at 5" will be identical. Barrel A ends acceleration at 5", while Barrel B is STILL accelerating. Acceleration = still getting FASTER, remember. The exit velocity of barrel A will be lower than barrel B, even though same amount of propellant was used. To fix this, you have to use more air with barrel A = less efficient. Like I mentioned before, with diminishing returns... it gets to a point where a longer barrel is no longer beneficial... and AGD has noted it to be around 8-10 inches.

The coefficients of friction of the ball and barrel will be very low. The work done by friction will be completely dwarfed by the work done by propelling the ball. If a train runs through an oncoming car head on... it's not going to have a big effect on it.

As far as your porting comment goes... you're getting into unnecessary precision wherein what I explained was sufficient in explaining the general idea. Porting is an exceptional case. Seal off the porting (which is another exceptional case, and not far-fetched) and then you got your 8-10" effective barrel on your one piece.

There's a lot of "what if's." I was shooting for a description of the general case - which is pretty much the important one.

[AutomagBoy]

sooo, whats more accurate one piece or two? This should be moved to deep blue.