barrel length

[Cade]

I have 2 Lilja barrels for 10-22, one is 16" and the other is 21" IF I was to get rid of one, which one should I keep? I do shoot from 25 out past 300 yds.
thanks

 

[Tony K Harper]

If they shoot about the same, sell the 16. If the 21 gets shot out you will still have enough barrel to cut it off and rechamber. The chamber end always goes first.
TKH

 

[Idaho-Lefty]

My 20", SS Green Mtn Barrel, shoots AWESOME / Tiny groups, and is very QUIET with, SK / Wolf Match Ammo that's, going BELOW, the speed of Sound ! That allows for Multiple shots at, Sage Rats Just in case, I miss, the first shot ( Chit Happens ! ). Got one at, 85 yards with, 2nd shot, last Spring !
Saw the Bullet hit the dust behind him, Left and corrected about 1.5 inches to right for, the Wind !
Was rested over a big Rock and,.. Yup, I use, a Range finder !

 

[PigButtons]

I would keep the 16 inch, especially for shooting longer distances. With the 22lr, after 16" the bullet is slowing down in the barrel and therefore the longer the shot the more drop from the 21".

 

[Outrider27]

The most accurate. 22lr use longer barrels. Never seen a barrel under 20" shoot as good as longer barrels.

I have. Depends on whether you are shooting irons or a scope. With irons, you definitely want the longer barrel for what it does for the sight radius, as a longer sight radius will will improve accuracy for most of us with irons. With scoped 22s I haven't found a significant difference in the accuracy with increased barrel length. With optics, the luck of the draw on the specific barrel and finding the ammo it likes have made the difference. YMMV.

 

[mrh1958]

Id go for the longer barrel, if you have ever chrono'ed 22 ammo you would see why, more consistent velocities from same ammo in both barrels, the longer being more consistent.

 

[HuskerP7M8]

I would keep the 16 inch, especially for shooting longer distances. With the 22lr, after 16" the bullet is slowing down in the barrel and therefore the longer the shot the more drop from the 21".

With the increase in velocity, the uncertainties in doping for the increased wind drift far outweighs the much more predictable dope for elevation. And, those uncertainties increase drastically the longer the distance to the target.

Landy

 

[Lefty Trigger]

I've had my best luck with 20's on several guns. Is true about the 16 being optimal length for powder burn ratio but I dont think anybody told the bullets about that.

 

[HuskerP7M8]

The most accurate. 22lr use longer barrels. Never seen a barrel under 20" shoot as good as longer barrels.

I very much doubt anyone other than me has ever done the testing to validate the statement you made because it would require using only a single long barrel with uniform taper lapping of 0.0002" to 0.0003" from breech to muzzle or a barrel totally uniform as regards bore dimensions over the same length.

If you pass that hurdle, you then need to test the barrel for precision and velocity standard deviation as you cut an inch at a time off said barrel.

If you want a reasonable statistical confidence level, it would be mandatory to fire at the very minimum 100 rds at the original length and again with each inch you cut off. You could use either 5-shot groups or analyze the entire 100-shot distribution using more robust or efficient statistics, which would be preferred to increase confidence levels. Something like MR (Mean Radius), RSD (Radial Standard Deviation), etc.

Landy

 

[HuskerP7M8]

Id go for the longer barrel, if you have ever chrono'ed 22 ammo you would see why, more consistent velocities from same ammo in both barrels, the longer being more consistent.

I've chronographed a few rds in my ballistic tunnel and I'm just shy of 120,000 total over a custom dual paired system of my own design. I won't say I'm 100% certain you're wrong, but the data I do have suggests shorter barrels are better in regards to velocity standard deviation. There's also a good reason why that may be the case because of the following discussion I had with Dr. Geoffry Kolbe some 8 or 9 years ago who is a physicist and ballistician who has authored several books on the subject as well as many technical articles:

"Hello Landy

That was a very interesting experiment. Thank you for sharing your results.

There have been a number of people who have cut down barrels an inch at a time (or the metric equivalent) and the velocity in those barrels increased slightly from 10 to 15 inches, but not very much.

Basically, peak pressure occurs when the bullet is barely out of the case and from about 6 inches on down the barrel, friction in the barrel is increasingly the dominant force on the bullet. From about 19 inches on, the velocity in the barrel is actually decreasing as friction does become the dominant force on the bullet.

As for the increase in SD in the longer barrel, I think that will be because friction is a significant force on the bullet from about 6 inches on. Friction robs the bullet of a given amount of energy per unit length traveled up the barrel. But the energy of the bullet goes as the velocity squared, so slower bullets will slow down quicker than fast bullets. This will lead to an increase in the SD with length of barrel.

Actually Landy, that was a very valuable piece of data for me! In my article "The Vibrations of a Barrel Tuned for Positive Compensation" I measured a rate at which the bullet travel time in the barrel varies with muzzle velocity. I got a rate of 1 millisecond for a change in muzzle velocity of 375 ft/sec. That was for a 26 inch barrel and I wondered if the rate would vary with barrel length.

At first, I thought the rate would change. But as a result of your experiment, I now think that this rate is pretty much a universal constant regardless of barrel length, and have changed my article accordingly.

So, in conclusion, I would say that all data is valuable - but it is only useful if you publish it....

Thanks again,
Geoffrey"

 

[Brsam]

I very much doubt anyone other than me has ever done the testing to validate the statement you made because it would require using only a single long barrel with uniform taper lapping of 0.0002" to 0.0003" from breech to muzzle or a barrel totally uniform as regards bore dimensions over the same length.

If you pass that hurdle, you then need to test the barrel for precision and velocity standard deviation as you cut an inch at a time off said barrel.

If you want a reasonable statistical confidence level, it would be mandatory to fire at the very minimum 100 rds at the original length and again with each inch you cut off. You could use either 5-shot groups or analyze the entire 100-shot distribution using more robust or efficient statistics, which would be preferred to increase confidence levels. Something like MR (Mean Radius), RSD (Radial Standard Deviation), etc.

Landy

Landy how many benchrest guns have you ever seen with a 16 inch barrel? Especially in 22 br? I'm going by numbers and not some tunnel shooting to validate it. I've never seen a 16" in the winners circle.

 

[HuskerP7M8]

Landy how many benchrest guns have you ever seen with a 16 inch barrel? Especially in 22 br? I'm going by numbers and not some tunnel shooting to validate it. I've never seen a 16" in the winners circle.

I've seen hundreds if not thousands of RFBR rifles over the many years I've shot with the major players in the game and only seen a few very short barrels, with none of them winning any National competitions.

Reread my post because I made no claim that I or others should go to shorter barrels. You, on the other hand, made a blanket claim of never seeing a barrel under 20" shoot better without providing any data whatsoever or an explanation for why that might or might not be true. I simply provided a means for you to find out for yourself.

Landy

 

[Tony K Harper]

Landy,

I find all this very interesting and would like to add my two cents. This comes from very basic practical experience and not a controlled experiment.

If one shoots a very accurate RFBR rifle at 50 yards and then moves to 100 yards. You will soon learn that the lost velocity of the longer barrel makes accurate shooting harder at the longer range.

I have two RFBR rifles one with a 24 inch barrel, the other a 19 inch barrel. The longer barrel will shoot circles around the 19 inch barrel at 50 yards. But I can nearly always get better scores with the shorter barreled rifle at 100 yards using the same ammo.

You may have guessed but yes, I did put on the 19 inch barrel just to shoot 100 yard targets.

This may not mean anything but it sure made me understand why short barrels are being put on so many rimfire rifles being used to shoot distances greater than 50 yards.

TKH

 

[jelenko]

Interesting.
What causes a 24" barrel to be more accurate at 50 yards than a 19" one?

 

[Tony K Harper]

Jelenko,

that is the 64,000 dollar question.
All I can tell you is every single winner and record holder I know shoots barrels longer than 19 inches. I have seen many short barrels used in RFBR matches but can’t recall any winners! I would never try to use my 19 inch barrel in a serious IR, ARA, or PSL match. But it kills at a 100 yards.
TKH

 

[HuskerP7M8]

Landy,

I find all this very interesting and would like to add my two cents. This comes from very basic practical experience and not a controlled experiment.

If one shoots a very accurate RFBR rifle at 50 yards and then moves to 100 yards. You will soon learn that the lost velocity of the longer barrel makes accurate shooting harder at the longer range.

I have two RFBR rifles one with a 24 inch barrel, the other a 19 inch barrel. The longer barrel will shoot circles around the 19 inch barrel at 50 yards. But I can nearly always get better scores with the shorter barreled rifle at 100 yards using the same ammo.

You may have guessed but yes, I did put on the 19 inch barrel just to shoot 100 yard targets.

This may not mean anything but it sure made me understand why short barrels are being put on so many rimfire rifles being used to shoot distances greater than 50 yards.

TKH

Hi Tony,

I don't have any hard data on why your 19" barrel might be better at 100 vs 50 and doesn't shoot as well as the 24" at 50, but I can speculate or hypothesize on a few variables that may play a part.

One factor could be velocity standard deviation, and I know from the analyses I've done that the statistical correlation to precision is weak at 50, but the correlation becomes a lot stronger at increased distances. Do you happen to see more vertical the majority of the time at 100 with your 24" vs the 19".

In case anyone reading this is slightly confused, all I'm saying is there is only a weak effect on scores produced at 50 that are attributable to the ES in velocity, but it's much stronger and should reduce scores at longer distances.

Now, this is only true when using true "Match" ammo, the likes of Eley Match, Tenex, Midas+. Unless I run into a bad lot of the aforementioned Match ammo, which is pretty rare, velocity SD runs consistently in the 6 fps to 8 fps range over a long string of shots. If you're shooting anything less than true Match ammo, you will often see atrocious numbers for ES/SD.

In any case we are still talking about some pretty small numbers for velocity lost due to barrel length and any benefits from a better velocity SD. Even worse it takes huge amounts of data to prove or disprove this hypothesis due to the fact that we shoot imbalanced bullets that cause unpredictable paths to the target at the longer distances.

It doesn't seem like this is discussed much, but these imbalanced bullets are due to their Cg (Center of Gravity) offset and are the major reason our RF's will never match the precision of CF's shooting nearly perfectly balanced jacketed projectiles.

For the statement above, I do have considerable data. It consists of 158 10-shot groups (1,580 rds) fired through a Meyton Electronic Targeting system at the Lapua customer service centers in Arizona and Ohio where you're able to see the group at both 50M and 100M. It might quite possibly be one of the more fascinating studies I've ever done and you wouldn't believe how much the size and patterns/shapes of the groups change. It's almost mesmerizing seeing the results.

I've also induced Cg Offset by drilling tiny holes in the bullet and firing them downrange in my tunnel. Using a formula I first saw in Vaughn's book "Rifle Accuracy Facts" and duplicated by several other ballisticians in the years since, I can fire a bullet while aiming at a dot and make it fly anywhere on the target I choose by indexing the offset in the chamber and varying the magnitude of offset. If it weren't so much work writing the algorithms incorporating the equation into a spreadsheet, I could shoot a smiley face on the target while firing every shot with the X-hairs on a single dot.

There's also another obvious factor. You have two different rifles with two different barrels and that makes it more difficult to draw any conclusion because other known and unknown variables due to the differences may be in play.

That's all I've got off the top of my head unless I think of something else later, and I'll always have more questions than answers anyway.

Landy

PS I hope this Covid business ends so we can get together again sometime and shoot instead of typing on internet forums. Maybe we can even discuss tuners again. LOL

 

[dellet]

Hi Tony,

I don't have any hard data on why your 19" barrel might be better at 100 vs 50 and doesn't shoot as well as the 24" at 50, but I can speculate or hypothesize on a few variables that may play a part.

One factor could be velocity standard deviation, and I know from the analyses I've done that the statistical correlation to precision is weak at 50, but the correlation becomes a lot stronger at increased distances. Do you happen to see more vertical the majority of the time at 100 with your 24" vs the 19".

In case anyone reading this is slightly confused, all I'm saying is there is only a weak effect on scores produced at 50 that are attributable to the ES in velocity, but it's much stronger and should reduce scores at longer distances.

Now, this is only true when using true "Match" ammo, the likes of Eley Match, Tenex, Midas+. Unless I run into a bad lot of the aforementioned Match ammo, which is pretty rare, velocity SD runs consistently in the 6 fps to 8 fps range over a long string of shots. If you're shooting anything less than true Match ammo, you will often see atrocious numbers for ES/SD.

In any case we are still talking about some pretty small numbers for velocity lost due to barrel length and any benefits from a better velocity SD. Even worse it takes huge amounts of data to prove or disprove this hypothesis due to the fact that we shoot imbalanced bullets that cause unpredictable paths to the target at the longer distances.

It doesn't seem like this is discussed much, but these imbalanced bullets are due to their Cg (Center of Gravity) offset and are the major reason our RF's will never match the precision of CF's shooting nearly perfectly balanced jacketed projectiles.

For the statement above, I do have considerable data. It consists of 158 10-shot groups (1,580 rds) fired through a Meyton Electronic Targeting system at the Lapua customer service centers in Arizona and Ohio where you're able to see the group at both 50M and 100M. It might quite possibly be one of the more fascinating studies I've ever done and you wouldn't believe how much the size and patterns/shapes of the groups change. It's almost mesmerizing seeing the results.

I've also induced Cg Offset by drilling tiny holes in the bullet and firing them downrange in my tunnel. Using a formula I first saw in Vaughn's book "Rifle Accuracy Facts" and duplicated by several other ballisticians in the years since, I can fire a bullet while aiming at a dot and make it fly anywhere on the target I choose by indexing the offset in the chamber and varying the magnitude of offset. If it weren't so much work writing the algorithms incorporating the equation into a spreadsheet, I could shoot a smiley face on the target while firing every shot with the X-hairs on a single dot.

There's also another obvious factor. You have two different rifles with two different barrels and that makes it more difficult to draw any conclusion because other known and unknown variables due to the differences may be in play.

That's all I've got off the top of my head unless I think of something else later, and I'll always have more questions than answers anyway.

Landy

PS I hope this Covid business ends so we can get together again sometime and shoot instead of typing on internet forums. Maybe we can even discuss tuners again. LOL

Time and again shooting subsonic centerfire, you see one hole 50 yards groups, turn into 6” vertical strings 1” wide at 200 yards. Looking at ballistic calculators you often see 10 fps ES accounting for at least half of that vertical.

As bullet quality drops from match grade to bulk cast, horizontal and vertical dispersion always seems to grow with little tangible explanation other than bullet quality.

Applying precision rimfire and air rifle thinking to centerfire subsonic shooting was a big help in shrinking groups. Being able to use quality bullets at subsonic speeds I think adds substance to many of the things you mention.

Some of the best centerfire subsonic bullets seem to also be ones known to be very stable passing through the trans-sonic speeds at distance. Example being bullets designed for Palma class.

These are just observations on thousands of rounds.

 

[Tony K Harper]

Landy,

Thanks for your reply. It really explains why ammo lot numbers can shoot so differently.

Here is another thing I believe, but can't prove.

Many times when I test ammo, I test by shooting through two chronographs. One at the muzzle, and one just in front of the target.

After narrowing down the lot numbers to the point I can't tell which is better I use the numbers from the two chronographs as a determiner. I do a little math (poor mans math) when I average averages. ( I know, my math teacher told me to never do this.)

But I want to see which ammo looses the most velocity between the two points. I figure the one that looses the less is flying truer. It is only slight but it makes me feel better before I write the check for cases of ammo.

Yea, I've bought a lot of crap ammo, but I've bought some good stuff too!!

BTW: When I can I still prefer to shoot slower ammo on winder days, and faster on less windy days.

You are absolutely right. We need to discuss tuners.

Another subject I suspect a lot about, but know very little.

I think it was Marty that coined the phrase " that is not tuning, that is just getting the rifle to shoot"

TKH

 

[Deveng]

Hi Tony

Do you see any correlation between the amount of velocity drop and the initial velocity?

Regards
Graham

 

[mrh1958]

I've chronographed a few rds in my ballistic tunnel and I'm just shy of 120,000 total over a custom dual paired system of my own design. I won't say I'm 100% certain you're wrong, but the data I do have suggests shorter barrels are better in regards to velocity standard deviation. There's also a good reason why that may be the case because of the following discussion I had with Dr. Geoffry Kolbe some 8 or 9 years ago who is a physicist and ballistician who has authored several books on the subject as well as many technical articles:

"Hello Landy

That was a very interesting experiment. Thank you for sharing your results.

There have been a number of people who have cut down barrels an inch at a time (or the metric equivalent) and the velocity in those barrels increased slightly from 10 to 15 inches, but not very much.

Basically, peak pressure occurs when the bullet is barely out of the case and from about 6 inches on down the barrel, friction in the barrel is increasingly the dominant force on the bullet. From about 19 inches on, the velocity in the barrel is actually decreasing as friction does become the dominant force on the bullet.

As for the increase in SD in the longer barrel, I think that will be because friction is a significant force on the bullet from about 6 inches on. Friction robs the bullet of a given amount of energy per unit length traveled up the barrel. But the energy of the bullet goes as the velocity squared, so slower bullets will slow down quicker than fast bullets. This will lead to an increase in the SD with length of barrel.

Actually Landy, that was a very valuable piece of data for me! In my article "The Vibrations of a Barrel Tuned for Positive Compensation" I measured a rate at which the bullet travel time in the barrel varies with muzzle velocity. I got a rate of 1 millisecond for a change in muzzle velocity of 375 ft/sec. That was for a 26 inch barrel and I wondered if the rate would vary with barrel length.

At first, I thought the rate would change. But as a result of your experiment, I now think that this rate is pretty much a universal constant regardless of barrel length, and have changed my article accordingly.

So, in conclusion, I would say that all data is valuable - but it is only useful if you publish it....

Thanks again,
Geoffrey"

Well I appreciate your input......actually there a a lot of variables in the conversation, I can only speak to my experience testing them, Lot of 52. 40x. Anschutz with 26" plus barrels that perform quite well, I think the pressure curve is equalized better in longer barrels.