Why the precision versions have shorter barrel

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DavidHarle

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Hello all,

shopping for a 17HMR, bolt-action, for target shooting at 100 meters. I noticed that in many cases, the 'Precision' version of the rifles have a shorter barrel than the regular version and that with the same 1-9 twist:

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Savage B17 - 21 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70801 )

Savage B Series Precision - 18 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70848 )
-------------------------------------------
Ruger American - 22 inches barrel ( https://www.ruger.com/products/americanRimfire/specSheets/8311.html )

Ruger Precision - 18 inches barrel ( https://www.ruger.com/products/precisionRimfire/specSheets/8402.html )
--------------------------------------------

WHAT ??? I must be really bad at understanding this. Has someone shot both of the same brand to compare in real life, not on paper ?

Thanks for educating me :)
 
For rimfire it has to do with when max velocity has been reached. The ruger American also comes in 18” compact and isn’t a precision model.

I really wouldn’t call any rinfire gun “precision” though
 
DavidHarle said:
If 18 inches are enough to reach max velocity with a 17 HMR, then why make a 22 inches barrel ?
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That sounds sensible, except I suspect many things are made because people will buy them - not necessarily because they are "best idea" - but they sell - therefore the makers and sellers make profit, so they make more, and cycle repeats - it all come back to "customer's choice".

There was a time, with black powder propellant, that some evidence that a longer barrel gave higher velocity - I doubt black powder has been used in even rimfire cartridges since 1920's - yet the thought "hangs on" - "facts" be dammed!

I think barrel length, powder burn rate, bullet velocity have been of interest to shooters for a long time - circa 1950's - reported in a USA NRA magazine, a guy named Phil Sharpe reported on a experiment that he did - started with a 30-06 with 30" long barrel - something like 6 or 8 different hand loads - different powders, different bullet weights - fired those rounds, sawed off an inch of barrel, then same rounds and so on until he was left with circa 11" barrel - he was shooting into a ballistic pendulum, I believe - a mind boggling undertaking to hand calculate that many muzzle velocities. As I recall, he demonstrated "faster burning" powders slowed down muzzle velocity as barrel got shorter - similar to "slower burning" powders. Some lengths actually had velocity same or increase when barrel cut an inch shorter. As I understand, that experiment has been repeated and reported on numerous times, with other cartridges and more modern powders - but you will still hear "sage advice" to use faster burning powder in shorter barrel, etc. as if nothing was ever shown to be opposite to that.
 
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Just found this very interresting:

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Now you're starting a whole different thread with your last question.

I don't know about the 17HMR as I haven't looked into the velocities.

I did do a bunch of research and even tested a few rifles chambered for 22LR. I used a model 75 Cooey with a 26 inch bbl and a lovely CZ 457 MTR with a heavy 20 inch bbl (belongs to a friend)

The results weren't spectacular, but were telling just the same.

The CZ MTR, with the same Aquil Super 22LR ammo, was of course much more accurate at 50 meters than the Mod 75 Cooey.

This wasn't a surprise. The Cooey didn't have a scope mounted and weighed in about a third lighter than the CZ.

I had been reading something from one of the rimfire sites in the US and UK about barrel length decreasing velocities but not impeding accuracy.

I don't remember the exact velocities but I do remember I shot 25 rounds of the Aguila ammo, from the same lot and box, through each rifle.

The CZ with the six inch shorter barrel, actually gave velocities an average around 30 feet per second faster than the Cooey.

This might change, with different ammo, such as CCI Stingers but I was just testing to satisfy my own curiosity.

I don't believe there is enough powder in most 22rf cases to keep expanding over the full length of the barrel at a rate that will overcome the resistance of the barrel on the bullet until it's out of the muzzle.

As for the reason some manufacturers make longer barrels?????? Why are some bunnies brown and others white or black????
 
I think the OP is making the mistake of assuming longer barrels are more accurate, which isn't really the case. It makes sense, target guns often have longer barrels than hunting rifles, but the reason the target guns have longer barrels is not accuracy.

The one exception is a gun with iron sights. A longer barrel typically means a longer sight radius, which generally leads to better accuracy from the shooter. Although then it's the shooter, not the gun, that is actually more accurate.

bearhunter said:
As for the reason some manufacturers make longer barrels?????? Why are some bunnies brown and others white or black????
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Genetics, which I don't think is the reason guns have longer or shorter barrels.... lol
 
DavidHarle said:
Hello all,

shopping for a 17HMR, bolt-action, for target shooting at 100 meters. I noticed that in many cases, the 'Precision' version of the rifles have a shorter barrel than the regular version and that with the same 1-9 twist:

-------------------------------------------
Savage B17 - 21 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70801 )

Savage B Series Precision - 18 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70848 )
-------------------------------------------
Ruger American - 22 inches barrel ( https://www.ruger.com/products/americanRimfire/specSheets/8311.html )

Ruger Precision - 18 inches barrel ( https://www.ruger.com/products/precisionRimfire/specSheets/8402.html )
--------------------------------------------
WHAT ??? I must be really bad at understanding this. Has someone shot both of the same brand to compare in real life, not on paper ?
Thanks for educating me :)
Click to expand...
Possibly with the idea of playing the Precision games, PRS moving about various props is handier with a short tube
 
DavidHarle said:
Hello all,

shopping for a 17HMR, bolt-action, for target shooting at 100 meters. I noticed that in many cases, the 'Precision' version of the rifles have a shorter barrel than the regular version and that with the same 1-9 twist:

-------------------------------------------
Savage B17 - 21 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70801 )

Savage B Series Precision - 18 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70848 )
-------------------------------------------
Ruger American - 22 inches barrel ( https://www.ruger.com/products/americanRimfire/specSheets/8311.html )

Ruger Precision - 18 inches barrel ( https://www.ruger.com/products/precisionRimfire/specSheets/8402.html )
--------------------------------------------

WHAT ??? I must be really bad at understanding this. Has someone shot both of the same brand to compare in real life, not on paper ?

Thanks for educating me :)
Click to expand...

Barrel length aside, why choose a .17HMR? It has nothing in its favour over .22LR, a much better choice.

Edit to add:

With regard to barrel length, there are several reasons why many models have shorter barrels. None of the reasons are related to better accuracy performance.

One reason is that's what many shooters believe is better. They accept the popular belief that faster bullets are better than slower ones. Faster rounds will have trajectories that are a little flatter but that doesn't make them more accuracy. In the case of .22LR slower rounds have less wind drift than faster ones. In any case, shorter barrels don't guarantee faster average MV's. That is to say, barrel length isn't always consistent with MV.

Another reason may be related to rifle balance. Some shooters find better balance with shorter barrels, others don't.

Some shooters prefer lighter rifles, some don't mind a little more weight. More mass means more inertia, and often that contributes to greater stability.
 
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Had a few 17's would go for a 22 these days
Also been looking at barrel lengths someone should post velocity results shooting from lets say a CZ457 varmint and the american to see just how much feet are lost
 
Read one test with the 17hmr, 20-21" was the max velocity they got with that particular ammo, also had the lowest SD/ES.
 
DavidHarle said:
Hello all,

shopping for a 17HMR, bolt-action, for target shooting at 100 meters. I noticed that in many cases, the 'Precision' version of the rifles have a shorter barrel than the regular version and that with the same 1-9 twist:

-------------------------------------------
Savage B17 - 21 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70801 )

Savage B Series Precision - 18 inches barrel ( https://www.savagearms.com/content?p=firearms&a=product_summary&s=70848 )
-------------------------------------------
Ruger American - 22 inches barrel ( https://www.ruger.com/products/americanRimfire/specSheets/8311.html )

Ruger Precision - 18 inches barrel ( https://www.ruger.com/products/precisionRimfire/specSheets/8402.html )
--------------------------------------------

WHAT ??? I must be really bad at understanding this. Has someone shot both of the same brand to compare in real life, not on paper ?

Thanks for educating me :)
Click to expand...

This is just my take. A shorter version of "anything", will be more rigid and less prone to bending, buckling or in the case of rifle barrels, less prone to whipping. This means every shot has a better chance of being more consistent down range.

I used to believe the longer the barrel, the more accurate. But my Weirauch HW97K air rifle is as accurate or more accurate than any other air rifle out there. In fact, its very popular in Field Target matches where the targets are literally only .30 of an inch diameter holes. Its barrel is only 12 inches.
 
DavidHarle said:
shopping for a 17HMR, bolt-action, for target shooting at 100 meters.
Click to expand...

Any particular reason you want a 17HMR for target shooting? Do you just have the desire to get a 17HMR? I ask because no target shooting organisations I'm aware of use that round. All rimfire target shooting is done with 22 LR, as far as I know. If you just want a 17HMR, that's one thing. If you're planning on doing any competitive shooting, or even if you'll only shooting by yourself but want to compare your results to published match results, you're going to want a 22 LR. Not to mention it will be cheaper to feed than a 17HMR. Garden variety 17HMR ammo is more expensive than Eley Tenex.

Jahnj0584 said:
I really wouldn’t call any rinfire gun “precision” though
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What a strange thing to say.

easyrider604 said:
This is just my take. A shorter version of "anything", will be more rigid and less prone to bending, buckling or in the case of rifle barrels, less prone to whipping. This means every shot has a better chance of being more consistent down range.
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A barrel needs to move (whip) to be accurate. An infinitely stiff barrel would not be beneficial. Barrel lengths and contours can be designed to move a certain amount and in a certain way, and give better precision as a result. I'd wager any of the various factory barrel contours would outshoot a hypothetical infinitely stiff barrel.
 
Story I heard about .22 target barrels being shorter was that with standard velocity target ammo, the powder is all burned up by 18 inches - they had extension tubes on the end of the barrel to hold the front sight. These guys were shooting at 25 metres indoors off their elbows with aperture sights.
 
AikiNut said:
Story I heard about .22 target barrels being shorter was that with standard velocity target ammo, the powder is all burned up by 18 inches - they had extension tubes on the end of the barrel to hold the front sight. These guys were shooting at 25 metres indoors off their elbows with aperture sights.
Click to expand...

Rimfire rifles designed for target shooting -- whether it's for benchrest or ISSF (e.g. Olympic-style smallbore competition) shooting -- have barrels that are typically longer rather than shorter. With very few exceptions, this is the case of ISSF rifles with barrel extensions. There are sound reasons for this.

________________

It's very possible the shorter barrels that are not uncommon among rimfire PRS-style shooters are related to the idea that the powder is "all burned up" within 18" of bore. The important premise is that barrels of this length allow higher potential ammo muzzle velocities, which some shooters may see as an advantage. In any case, ammo MV is not always consistent with barrel length. Bore characteristics are critical factors in ammo MVs.

Of course, whether the powder is "burned up" in an 18" barrel or the round continues on in a longer one has nothing to do with accuracy potential. That is a product of both barrel quality and ammo quality. Faster .22LR match ammo isn't more accurate than slower match ammo, regardless of distance.

When shorter barrels are preferred, it's not because they are more or less accurate than longer ones. It's for reasons of handling and balance. Long barreled rifles may sometimes be more ungainly in PRS-style shooting. They also serve to satisfy shooters who believe that faster ammo is preferable, regardless of whether that preference is based on accuracy performance or not.
 
My 2 cents:

I think easyrider604 nailed it. In the next comment, _shorty is also talking about barrel harmonics (I believe there are two waves happening at once in gun barrels). That's at the core of these short heavy barrels. With centrefire, you can develop a load that times the bullet travel with the barrel whip so that it leaves the buzzle at as close to the same instant as possible (making it more repeatably accurate). With rimfire, where you can't do this, you'd want this barrel wave minimized as much as possible so that it's less sensitive to ammo choice.

In really good rimfire barrels there's also a tight spot in the bore, ideally as close to or right at the muzzle. I had an old Valmet Lion target gun that had an irregular barrel length - you can see it had been cut -, but it shot sooooooo good with SK red. A gunsmith told me that, most likely, it was cut at the point where the constriction was to improve accuracy and consistency shot over shot.

Lastly, high velocity isn't really synonymous with accuracy in rimfire target shooting (except maybe at longer ranges). There's a sweet spot where it's fast enough to be less sensitive to wind, but still stays subsonic to avoid the turbulence created by the sonic "crack" reaching the bullet as it slows down. That sonic "boom" can destabilize the bullet in flight. Or so I've read.
 
Canuck65 said:
Lastly, high velocity isn't really synonymous with accuracy in rimfire target shooting (except maybe at longer ranges). There's a sweet spot where it's fast enough to be less sensitive to wind, but still stays subsonic to avoid the turbulence created by the sonic "crack" reaching the bullet as it slows down. That sonic "boom" can destabilize the bullet in flight. Or so I've read.
Click to expand...

With .22LR faster doesn't mean less sensitive to wind. It's the opposite. The faster a .22LR round is the more it drifts in wind. For minimizing wind drift, slower is better.

High velocity .22LR bullets don't experience the transonic turbulence that affects some projectiles. Transonic turbulence occurs when some bullets slow down into the transonic zone velocities, which are from about 1340 fps to about 890 fps. Most HV .22LR ammo spends the first 175 yards or so of it's flight entirely within the transonic zone speeds. So, too, does standard velocity .22LR match ammo. High velocity .22LR ammo is usually accuracy impaired for reasons of quality not velocity.
 
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