What is the perfect barrel length? 22 Rimfire Edition.
- Thread starter The ROC
- Start date
What a great opportunity to do some good testing. The testing in the video begins with rifle with a 46.5 inch IBI barrel (made from two barrels put together). It's shot with a chronograph and progressively shortened. Average MV and SD are shown. The ammo was SK Rifle Match. Ten rounds were shot at each barrel length and recorded with the chronograph and on the target.
The video is called "Finding the Perfect .22LR Barrel Length". Does it do that? Is the testing successful? Is there a "perfect .22LR barrel length?"
Below are some of the salient images from the video.
First, the rifle with the barrel at full length, before it gets shortened. The shortening is done a hand power tool and the crown finished at the range with a hand-operated "reamer tool".
Second, the chronograph results.
Third, the results on target for each barrel length.
The video is called "Finding the Perfect .22LR Barrel Length". Does it do that? Is the testing successful? Is there a "perfect .22LR barrel length?"
Below are some of the salient images from the video.
First, the rifle with the barrel at full length, before it gets shortened. The shortening is done a hand power tool and the crown finished at the range with a hand-operated "reamer tool".
Second, the chronograph results.
Third, the results on target for each barrel length.
The video is a wasted opportunity. The testing was compromised for the sake of saving time.
One, the testing is very inadequate. Ten rounds at each barrel length is insufficient. Furthermore, the ammo itself is not usually consistent enough to draw sound conclusions -- especially with only ten round tests. Better ammo should have been used, and more of it.
Second, the finishing of the crown may not be consistent with each progessive cut. The MDT guy doing the test says as much himself toward the end of the video at around the 5:30 mark. "Maybe I didn't have the crown cut quite square." He adds that "environmental" factors -- the wind -- may have influenced results. We will never know.
Many of the video's comments were fulsome with praise, but don't let that fool you. The video test as it was done is hardly worth the effort and expense behind it, unless MDT is to be commended for trying (everyone gets a ribbon).
The best observation made during the course of the testing was near the end. Saying that balance is important and that it's hard to beat a 20" barrel, the tester says there are a lot of options out there but rules out none of them. Most importantly he says "obviously the speed [muzzle velocity] doesn't really matter."
Muzzle velocity doesn't matter. In fact it's better to use slower ammo in windier conditions, especially as range increases.
One, the testing is very inadequate. Ten rounds at each barrel length is insufficient. Furthermore, the ammo itself is not usually consistent enough to draw sound conclusions -- especially with only ten round tests. Better ammo should have been used, and more of it.
Second, the finishing of the crown may not be consistent with each progessive cut. The MDT guy doing the test says as much himself toward the end of the video at around the 5:30 mark. "Maybe I didn't have the crown cut quite square." He adds that "environmental" factors -- the wind -- may have influenced results. We will never know.
Many of the video's comments were fulsome with praise, but don't let that fool you. The video test as it was done is hardly worth the effort and expense behind it, unless MDT is to be commended for trying (everyone gets a ribbon).
The best observation made during the course of the testing was near the end. Saying that balance is important and that it's hard to beat a 20" barrel, the tester says there are a lot of options out there but rules out none of them. Most importantly he says "obviously the speed [muzzle velocity] doesn't really matter."
Muzzle velocity doesn't matter. In fact it's better to use slower ammo in windier conditions, especially as range increases.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
It did reinforce something rimfire shooters have believed for decades... lengths OVER 16" decelerate the 22lr
The goto lengths have been from 18" to 20" ... seems good old fashion trial and error was right.
SD is such a crap shoot but shooters still like to hang their testing on it... data provided showed a very stable range YET the results on paper were anything but. There was no correlation between SD and group size.
It was interesting to see how the load 'tuned' with varying lengths. I agree that 1 group does not an average make but still shows how sensitive rimfire can be to barrel harmonics (tuners.. hint, hint)
All I got from it was overly long OR overly short, don't help your cause. Decades of rimfire rifles has shown where things tend to work the best. The quirks of any particular end use and rules can help determine "best"... but the ammo really doesn't care.
Reading the wind has and will always matter far more then some 'ultimate' set up. Translation... spend less... practise more.
Jerry
The goto lengths have been from 18" to 20" ... seems good old fashion trial and error was right.
SD is such a crap shoot but shooters still like to hang their testing on it... data provided showed a very stable range YET the results on paper were anything but. There was no correlation between SD and group size.
It was interesting to see how the load 'tuned' with varying lengths. I agree that 1 group does not an average make but still shows how sensitive rimfire can be to barrel harmonics (tuners.. hint, hint)
All I got from it was overly long OR overly short, don't help your cause. Decades of rimfire rifles has shown where things tend to work the best. The quirks of any particular end use and rules can help determine "best"... but the ammo really doesn't care.
Reading the wind has and will always matter far more then some 'ultimate' set up. Translation... spend less... practise more.
Jerry
- Location
- Blaster land, Okanagan BC
20-22” has been my personal sweet spot for barrel length, it checks all my boxes.
Nothing is confirmed with this video/test. That's the main problem with it.
With one group shot at any length no one can know much about the rifle's accuracy. One group is meaningless.
Mike Bush from Vudoo will usually recommend a barrel between 16 and 20 inches.
It's a question of velocity versus overall balance imo. I don't think it matters much and it's more of a personal preference.
My Tikka with a 16 inches barrel do look weird in a chassis though.
It's a question of velocity versus overall balance imo. I don't think it matters much and it's more of a personal preference.
My Tikka with a 16 inches barrel do look weird in a chassis though.
Mystic Precision
CGN Ultra frequent flyer
- Location
- Summerland, BC
Strictly through the lens of rimfire PRS, my rifles are limited to 20" barrel... I will use a tuner if it helps and I prefer a tuner that doesn't extend beyond the muzzle. I have tried longer but it didn't yield any improvement and just made it hard to move around.
The trend is to really large diameter long barrels and the assumptions is they shoot 'everything' well. If they do, great... if they don't, there is little a tuner, of reasonable weight, can do to have an affect as the barrel is simple too stiff/heavy.
I have gone with what used to be HBs like the 0.920" 10/22 profile AND sporter barrels. These respond to tuners of typical weights... just in case.
The balance is metal ballast on the stock as needed. I am not a fan of a long overall length as that can slow down movement in and out of props.
BUT this is certainly shooters preference.... I suspect as the rifles get longer, the need to move in and out of props or narrow openings shrinks.
Seems to be the way of this game....
Jerry
The trend is to really large diameter long barrels and the assumptions is they shoot 'everything' well. If they do, great... if they don't, there is little a tuner, of reasonable weight, can do to have an affect as the barrel is simple too stiff/heavy.
I have gone with what used to be HBs like the 0.920" 10/22 profile AND sporter barrels. These respond to tuners of typical weights... just in case.
The balance is metal ballast on the stock as needed. I am not a fan of a long overall length as that can slow down movement in and out of props.
BUT this is certainly shooters preference.... I suspect as the rifles get longer, the need to move in and out of props or narrow openings shrinks.
Seems to be the way of this game....
Jerry
I enjoyed the video, and generally enjoy the content they've been putting out - especially the height over bore video. Certainly not scientific, but entertaining and provided some high level information that might be useful to some.
Elsewhere in the Rimfire forum of CGN you've referred to tuners that don't extend beyond the muzzle. The ones described were not "mid-barrel tuners" (literally placed in mid-barrel) which work in conjunction with a standard type of barrel tuner.
As a vendor who has an interest various products, can you tell readers if there is a commercially available tuner that is as described? Or is it something self-manufactured? Are such devices in use by serious rimfire shooters anywhere else?
With the tested ammunition, yes. And yes, most target ammunition is probably very similar in this.
Coming from someone who sells stuff to make those same ultimate setups, that's very refreshing!
Are you thinking of Ballistics by the Inch? They did some actual science in that study, which is pretty unusual for this industry.
And unfortunately, the group sizes in this video tell us absolutely nothing, because as grauhanen says:
Utterly. Meaningless.
The MV data is useful. The SD and POI shift data is potentially useful. Unfortunately, I think putting the group sizes in the video makes it pseudoscience.
Agreed.
The Ballistics by the Inch study is of questionable usefulness because of the limitations in the testing. For .22LR the testing involved shooting only six rounds of each variety of ammo at each barrel length. That is far too small a sample size to be reliable.
With regard to the video/test, in what way is the video/test MV data useful? What relationship, if any, might there be between SD and POI shift?
It's fair to assess the group sizes as having extremely limited, if any, value. A single group almost always reveals very little.
The BBTI study is a great topic for another thread, I don't want to derail this one by going into depth.
The data in this study is pretty noisy. Increased sample size would have been easy enough to do, and may have smoothed things out. And because of the methods, I have serious doubts about reliability. But in my opinion, just because it's not perfect (or even "pretty good") doesn't necessarily mean it's entirely useless.
I think the MV data is useful in that it clearly shows a relationship between barrel length and MV. And it (probably) shows a peak MV at 16" barrel length (for this ammunition, in this barrel). It's not definitive, and it's nothing new, but it does confirm similar observations from other datasets. And I certainly had very little idea what MV was going to be out at 30" or more of barrel length, so that was interesting (even if academic).
I have nothing to say about a relationship between SD and POI shift - I was noting that they are each (individually) potentially useful. I found it interesting to observe that in general the SD did not show an apparent relationship to barrel length. And while I don't particularly care about POI shift, I'm sure others do.
For readers in general, it's important to understand the nature of the .22LR barrel length and muzzle velocity relationship. Despite internet lore, it's not consistent. In other words, it's not possible to say that a shorter barrel will always be faster than a longer one and a longer one always slower.
In this video/test, in terms of average length barrels -- that is from about 18" to 26" (relatively few target shooters use very short or very long barrels, with anything over 27" being currently increasingly rare) -- the testing in the video shows nothing conclusive. For anyone in doubt, look at the data in post #2.
It's worth noting that Bryan Litz has concluded that the relationship between barrel length and MV with .22LR is, in his words, "difficult to detect". In other words, barrel length doesn't consistently contribute to muzzle velocity. Other studies support this finding.
See, for example, h ttp://forums.accuratereloading.com/eve/forums/a/tpc/f/8711043/m/4871072832
As for SD, the figures in the video/test are for ten rounds. Readers may note that ten shots over a chronograph reveals little that's useful because the sample size is too small to be meaningful. POI shift will have little, if anything, to do with random SD figures but more to do with changing position/hold when moving from one bull to another.
