velocity vs. barrel length

O

old_snake

Guest
i am getting weary of this go around with a friend of mine

this is the senerio; ammo with appx fps speed 1050 to 1070
shot from two guns, one having a barrel length of appx 22 1/2 inch and the other 26 inch length

which one will have the faster muzzel speed

has any one done any real speed testing to give me a difinitive answer ?
 
In theory the shorter barrel should have higher velocity, however due to differences in barrels, even those supposedly identically and ignition and any other variable you can think of it's hard to be sure. The only way to be somewhat sure is to take a dozen barrels, set them all to 26 inches, measure, then cut them to 22 inches and measure again. Oh and have the temperature, humidity and barometric pressure the same. But in generalities the longer barrel will have a lower velocity. Which is goodness for accuracy in the wind, sometimes.
 
My results

I've tested barrels from 22 to 30 inches in length, and got the highest velocity from the longer barrels. The barrels were all different twist and inside diameters, and that could have influenced the results. I'll see if I can find the results and send them to you. If you really need to know, then set up a chronograph and prove it for yourself.
 
Nobody's seen the test where a guy took a long barrel, tested several different types of ammo, and cut it back an inch at a time and retested? I'll look for the results again, but IIRC all ammo was slower with the longer lengths, until it got down to the 16-18" range. Stated another way, maximum velocity was achieved in the 16-18" range, with shorter barrels giving lower velocity, and longer barrels also giving lower velocity. All the powder appeared to be burned by 16" or so, and after that any extra barrel length just began slowing the bullet again. I'll come back with the link when I find it.
 
old_snake said:
i am getting weary of this go around with a friend of mine

this is the senerio; ammo with appx fps speed 1050 to 1070
shot from two guns, one having a barrel length of appx 22 1/2 inch and the other 26 inch length

which one will have the faster muzzel speed

has any one done any real speed testing to give me a difinitive answer ?
Click to expand...

There is no definative answer, along with lenght you have bore dia., taper,lap, style and number of lands. Unless you want to measure one bbl. as you cut it down you are'nt going to compare apples to apples
 
Last edited:
Tim
Was it Bullberry that performed the test? I believe they started with a long barrel and cut off an inch at a time?
Colt.45
 
This question comes up about every year or so.

The following information is from Mark White's book "The Ultimate Ruger 10/22 Manual and User's Guide" . Apparently, he cut a 28 inch barrel two inches at a time and measured for muzzle velocity.

Ruger 77/22; Remington Standard Velocity .22 LR ammunition
Barrel Length/ Velocity
28 1095
26 1107
24 1119
22 1129
20 1138
18 1149
16 1157
14 1149

So, based on this, it would seem maximum velocity in a .22 is acheived at 16" with a loss of about 5 fps/inch over the next 12 inches.
 
David Valdina said:
I looked at the paragraph dealing with velocity and barrel length, and that is correct.
Click to expand...

David, I think you missed my original point. If you are going to make anything other than kind of a general comparison, there is no such thing as two "identical" bbls.
 
Colt.45 said:
Tim
Was it Bullberry that performed the test? I believe they started with a long barrel and cut off an inch at a time?
Colt.45
Click to expand...

As I recall it might be . I know that Anschutz did something similar back befor true tuners trying to reduce vibrations with short bbls and a bloop tube. I did a lot of homework way back because I was fairly lucky to get on of the first 10 Anschutz 2007 barreled actions in the country, remember when the .22 world revolved around "adjustable headspace"?
 
Back to Tim, again

Tim, You seem to want to pick at the contrary. The original post asked about help in setting a fellow straight about barrel lengths and velocity. Now I don't really care about all kinds of variables other than barrel length in this discussion. All things being equal with .22 rimfire ammo, a 16 to 18 inch barrel will have faster velocities than a 24 to 28 inch barrel. It all has to do with the expanding gases that drive the bullet and when they don't expand any more. Plain, simple, easy to understand and answers the original question. Why don't you start a new post about the other variables you want to discuss ? Might be interesting.
 
tim said:
I know that Anschutz did something similar back befor true tuners trying to reduce vibrations with short bbls and a bloop tube.
Click to expand...
ISSF shooters had quite a bit of trouble with their short barrels/bloop tubes back when Federal was launching their ammunition here in Australia back then. In the hotter months, maybe one in four would go supersonic in the short tubes. Apart from being a noisy surprise, they didn't hold the group at all well.

I recall being told that one of the reasons smallbore rifles had long barrels was to even out velocities, but that could have been based on hindsight.
 
David Valdina said:
Tim, You seem to want to pick at the contrary. The original post asked about help in setting a fellow straight about barrel lengths and velocity. Now I don't really care about all kinds of variables other than barrel length in this discussion. All things being equal with .22 rimfire ammo, a 16 to 18 inch barrel will have faster velocities than a 24 to 28 inch barrel. It all has to do with the expanding gases that drive the bullet and when they don't expand any more. Plain, simple, easy to understand and answers the original question. Why don't you start a new post about the other variables you want to discuss ? Might be interesting.
Click to expand...

I'd suggest instead of spending time on those comedy sites you call up a couple barrel makers to start your education. Wanna bet I can come up with 1/2 dozen bbls. that are longer but slower than different configuration but shorter bbls. Want to come test with my chrono.? Come visit, bring money, we'll wager a bit. Why do you think these guys brought up the tests using cut versions of the SAME bbl?
 
Tim, why pick a fight ?

Maybe it's just me, but you are coming across as a jerk. I bet if anyone wanted to take the time to go through your posts, a goodly percentage of them would be contrary, negative and/or just plain argumentative.
 
David Valdina said:
Maybe it's just me, but you are coming across as a jerk. I bet if anyone wanted to take the time to go through your posts, a goodly percentage of them would be contrary, negative and/or just plain argumentative.
Click to expand...

What exactly did you expect when the guy asks a question on a precision forum and you post up this utterly foolish reference on a 10/22 site?
 
Let's see...

Old_Snake joins a few days ago, asks a question, and I try and give him an answer he can use. Mind you, he in turn will be giving this info to his friend. For reasons known best to you, you try and say there are too many variables, ie, can't have an easy answer, then start slamming others who dare using rather pedestrian sources rather than the highly esoteric level to which you pretend to rise. People will forget what you said, and people may even forget what you did, but people do not forget how you made them feel. You are not coming across as a kind and caring person, is that what you intend ?
 
You must log in or register to reply here.
Back
Top