Barrel length vs velocity

K

Keith23

Guest
Many on this board have stated that rimfire barrels longer than 16-18 inches, will slow bullets down.

Is this really true? I was rereading some old articles in Precision Shooting and I ran across an article about Clay Spencer the Virginia gunsmith. This was in the March 1994 issue.

Some may recall, Clay shot BR-50 back in the early 90’s . He did quite well.

Anyway the article mentioned a test Clay did on barrel length vs. velocity. Clay installed a 28 inch barrel on a 40X, and fired 250 rounds though a chronograph. He then cut the barrel off 1 inch at a time, and repeated the test until he got down to 18 inches. That is a lot of shooting.

Clay then reported that there was an avg. 16 foot per second difference between 28 inches and 18 inch , but low and behold, the longer 28 inch barrel, shot faster than the 18 inch barrel.

Has anyone else conducted such a test. If so, please share.
 
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For what its worth , A freind shot some wolf m/t through his 26 inch barrel 40x at 1055fps , from the same box it shot 1105 out of my 14 inch contender barrel.
 
The same basic test has been conducted and shows the opposite. I'll find it and post it if I can.
 
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.
 
Thanks for posting that Wally. I had quoted in a post about barrel length that it took about 16" to effectively burn all the powder, I just didn't know where I had read the reference.


Beau said:
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.
Click to expand...
 
Every barrel is different

My test showed some longer barrels produce higher velocity and some slower. Take your pick. I still prefer the longer barrel. Velocities will be more consistant.
 
Use a 28" barrel and match RF ammo at 50 yards in the sun and you'll see the bullet arch in most of the time even though you may not realize what it is at first. Use a 20" barrel and you won't. I prefer longer barrels as well, but that doesn't change what they do to velocity.
 
Clay summed up his test by saying he thought a 26 inch barrel was about ideal for most conditions and that every shooter should alway try different speeds of ammo to see what speed shoots best for the current condition. In other words, there is no best speed of ammo, just ammo that handled a particular condition better than others. Remember all of this was written in 1994 and that was before widespread use of tuners.

I don't know if Clay ever reads these threads but it sure would be good to hear from him.
 
same velocity round, 50 yards doesn't matter 20" or 30" barrel within a few thousandth of the same arc. it all depends on line of sight, power and clarity of scope when a bullet passes. lenght of barrel has no effect.
 
confucius wrote around 500bc," those that fail to understand .22 caliber ballistics will never understand the concept of tuning".
 
martin hammond said:
confucius wrote around 500bc," those that fail to understand .22 caliber ballistics will never understand the concept of tuning".
Click to expand...


Martin,

I once had a 40X with a 28 inch barrel. When I would shoot it at 50 yards, I thought I was hitting something because it appeared to be some type of material flying off the target. I checked the target, nothing. I shot the other gun, using the same scope, same light conditions, etc. but it had a 20 inch barrel. I didn't see anything and though no more of it. Few days later I was out shooting the same guns. Noticed the same thing. Finally figured out it was the bullet, which occasionally, you can see even if the barrel is 20 inches. But with the 28 inch barrel I could see it every time. So, I went to the 20 inch to attempt to see it. I think maybe I caught a glimpse one time, but that was all. That 40X shot pretty good, but always seeing that bullet just somehow messed with my mind. Maybe I thought I should be able to see exactly where it was going.

Anyway, after that, each time I would shoot a long barrel gun, I would see if I could see the bullet. Almost, not always, I could. Shorter barrel I could not.

So, whatever you think you know about theory, there's a real world out there that doesn't necessarily adhere to it. Maybe it's elevation, that would be about the only true difference I would know between you and me. Or maybe I just noticed it and you never did. But from that point on, I never doubted that a longer barrel slowed the bullet. Which I really didn't doubt it anyway.

I don't really want to hear your disagreements and arguments. You believe what you want and I'll believe what I want and we'll both be happy. By the way there was no tuner on either rifle.
 
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Martin

martin hammond said:
confucius wrote around 500bc," those that fail to understand .22 caliber ballistics will never understand the concept of tuning".
Click to expand...

Confucius also say, "Those who can not perform in competition become teachers and post crappy targets and graphs to explain tuning".
 
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Is this what you are seeing?

I believe that it is the light conditions and not the length of the barrel. When we have bright sunlight on the bullet and the target side we shoot at is shaded it is most pronounced. I believe that if we were shooting at a black target with white rings we could see the bullet approach even better.

What I see is the bullet and it seems to follow a semicircular path like a "C" with it's open side on the bottom. it appears to travel up then right then down not unlike a curve ball.

I first saw this with other shooters and they were seeing it too. One of the more experienced shooters said, "It's a dang wonder that we ever hit the target".:)

Concho Bill
 
No, in your case it may be light. In this case it was the length of the barrel. That was the only variable. Now the shorter barrel may have shot flatter, but that still gets you to the same point.
 
in the gun where it slowed down it was a 10-22 open blowback type
action.
in the gun where it sped up i believe was a 40x closed locked action.
wouldn't that make a difference?
also wouldn't how tight a chamber and bore are make a difference?
looks like testing using the same action and barrel and lopping off the
barrel is the right way to check this, but only if there was no choke
in the end of the barrel, because once you cut the end off that
constriction wouldn't be there, and that would alter things i would think.
 
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Tom C.
To correctly experiment with this barrel length deal you must lop off the chamber end and re-chamber and leave the choke end undisturbed. Otherwise you must use a non choked barrel to begin with and that is another can of worms.

Carp
 
even the largest power scope has the degrees neccesary to see a .22 rounds trajectory, the reasons some do not see is poor eyesight, clarity and contrast of the scope.but the main reason is parralax, the .22 round no matter what lenght of barrel is always there in the field of veiw of every scope. there is no match .22 round that is ever out of the field of veiw even on a 60 power scope.
 
i'm don't know carp to do that you would have to have identical
chambers everytime. i'm pretty sure when i've read about people
testing like this, it's been by lopping off the muzzle end. now if
the choke was taken out beforehand by lapping or however you
could probably get a truer reading. then you could just do your
lopping.
 
i've heard if you knock the parralax out slightly you can sometimes see your
bullets. he must've had one of them c barrels.
 
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