Optimum Barrel Length for .22LR

[tmwinds]

I think it is so they can compete @ 100 yds and maintain enough velocity for the bullet to remain at or above the speed of sound. Projectiles suffer from instability as they transfer to subsonic velocities. As for accuracy. I think the longer the barrel the higher quality it needs to be to remain consistent. I have a home built semi auto 10/22 with a 20" Volquartsen .920" dia barrel that will shoot cheap Norma TAC22 well under 1/2" groups @ 50 yds and still be 1/2", but have 1 or 2 fliers @ 75. At 100 it is over an inch. If it were a bolt rifle with that barrel I think it would do better.
20" does it for me.

All of the decent .22 LR target ammo I familiar with is subsonic for a reason. It does not have to make the transition to subsonic. It starts that way.

 

[tmwinds]

I thought federal law requires a minimum barrel length of 17 inches....

16 inches from the bolt face to the muzzle.

 

[1813benny]

Agreed, but competitors competing in Biathlon and Olympic rifle disciplines have rifles that exceed 20".
So the question is :

Is the increased sight radius that much of a advantage over increased velocity in those disciplines?

Olympic Postional Indoor Shooting with no wind . Absolutely.

Biathlon shoots Outdoors at 50 M ( 54 Yards ) at targets 4.5" and 1.5".
Once again , the sight radius wins.

Iggy,
Prone and position shooters do not care about barrel length’s impact on velocity. We compete at 50-100 yards and only use subsonic match ammunition.

Proper sight radius is very important. First, the greater the sight radius, the more it assists with sighting and also is more in line with your eye’s ability to focus with the front sight further out.

The additional barrel length is also a benefit as it adds to the overall weight of the rifle. A moderately heavy rifle that is well balanced is an advantage for smallbore prone and position disciplines.

That weight is also important on the muzzle end of a biathlon rifle to minimize movements while trying to shoot with a pounding heartbeat.

Regards,
Ken

 

[Iggyort]

Iggy,
Prone and position shooters do not care about barrel length’s impact on velocity. We compete at 50-100 yards and only use subsonic match ammunition.

Proper sight radius is very important. First, the greater the sight radius, the more it assists with sighting and also is more in line with your eye’s ability to focus with the front sight further out.

The additional barrel length is also a benefit as it adds to the overall weight of the rifle. A moderately heavy rifle that is well balanced is an advantage for smallbore prone and position disciplines.

That weight is also important on the muzzle end of a biathlon rifle to minimize movements while trying to shoot with a pounding heartbeat.

Regards,
Ken

Ken

Finally the explanation I suspected.

Thank you.

Iggy

P.S. Congratulations on your win last weekend . I had to run and could not stay for the ceremonies.

 

[1813benny]

Ken

Finally the explanation I suspected.

Thank you.

Iggy

P.S. Congratulations on your win last weekend . I had to run and could not stay for the ceremonies.

Thank you sir!

 

[SBS]

Another comment on barrel length and it's effect on velocity. For example, the subsonic velocities that were printed on Eley Match & Tenex ammunition (until recently) were from 26" Anschutz barrels (per Eley). When shooting shorter barrels, there is less velocity loss from less drag after the powder burns out. At some shorter barrel length (around 20" or less, in warm weather particularly) the round may be supersonic as it exits the muzzle. This means it will become subsonic before it arrives at a 100 yd. target which is not good for accuracy and wind drift. I suspect the increasing number of match rifles with short barrels (both position and silhouette) were the reason Eley gradually started offering lower velocities. Most of their top ammo used to be in the 1070's and gradually they offered lots in the 1060's, 1050's and 1040's -- where there is less chance of rounds being supersonic because of shorter barrels.

 

[rmist]

Iggy...if you have a barrel blank of 28" and send to a rimfire gunsmith. He's going to slug your barrel, not just loping it off any ol place. To find the best place for the muzzle end crown. It's a place in the barrel basically where it's the tightest and roundest for where bullets exit. Like said above, almost all benchrest barrels are long 24"-26". My barrel is 25 1/2" long. For Smallbore F Class don't need to worry about barrel length. You're not running around swinging the rifle. Plus these rifles probably will never be over weight. You've seen how mine shoots with a fairly long barrel. So...what are doing...rebarreling your rifle? Or pondering cutting it...I would not cut it at all if I were you. Find ammo it likes !!!

 

[Jim Hankins]

I thought federal law requires a minimum barrel length of 17 inches....

Nope...

 

[jbell]

Another comment on barrel length and it's effect on velocity. For example, the subsonic velocities that were printed on Eley Match & Tenex ammunition (until recently) were from 26" Anschutz barrels (per Eley). When shooting shorter barrels, there is less velocity loss from less drag after the powder burns out. At some shorter barrel length (around 20" or less, in warm weather particularly) the round may be supersonic as it exits the muzzle. This means it will become subsonic before it arrives at a 100 yd. target which is not good for accuracy and wind drift. I suspect the increasing number of match rifles with short barrels (both position and silhouette) were the reason Eley gradually started offering lower velocities. Most of their top ammo used to be in the 1070's and gradually they offered lots in the 1060's, 1050's and 1040's -- where there is less chance of rounds being supersonic because of shorter barrels.

Exactly, this is not centerfire and more velocity is not a good thing for accuracy. I have been lucky enough to have owned a lot of very accurate top end rimfire rifles over the years and every single rifle was more consistent with a lower FPS lot of ammo when compared side by side with the same ammo from a faster lot. In addition I have found barrels of 24-27 inches tend to produce more consistent accuracy, not necessarily the most extreme accuracy but the most repeatable results day to day. I think the name of the game as far as MV & barrel length is staying as far away from the transonic velocity as you can, because if your close there are those days when the conditions are right and the velocity creeps up some.

 

[garandman]

Exactly, this is not centerfire and more velocity is not a good thing for accuracy. I have been lucky enough to have owned a lot of very accurate top end rimfire rifles over the years and every single rifle was more consistent with a lower FPS lot of ammo when compared side by side with the same ammo from a faster lot. In addition I have found barrels of 24-27 inches tend to produce more consistent accuracy, not necessarily the most extreme accuracy but the most repeatable results day to day. I think the name of the game as far as MV & barrel length is staying as far away from the transonic velocity as you can, because if your close there are those days when the conditions are right and the velocity creeps up some.

Definitely true for my Lilja barrelled CZ 457, and seems to be so in my V-22 for which I just started testing ammo. 1080 fps ammo seems a lil too hot. The Lilja barrel likes 1059-1060 ffs.

 

[Jallen]

I run suppressors on most of my rimfires. For the ones that are just for plinking, if they are not super expensive rifles,,i cut to 16 inch. This helps keep cheaper bulk ammo running slower and quieter. On rifles i want the most accurate i can get,, i cut where slugging says i should cut.

 

[Rsadams]

Seems like alot of companies have settled on 18 inches.....

 

[FrankG]

In terms of velocity for the most part a 16” burns up all the powder in a .22RF.

Barrel length vs. accuracy.....the longer barrels in a pure accuracy test won’t be any better per say.

As has been said if your a position shooter the longer barrel and with shooting iron sights helps your sight radius which helps the shooter but if your shooting a scope then the barrel length doesn’t mean as much.

I rebuilt a couple of 52D’s. One duplicated the 28” barrel length and the other as a position rifle but finished the barrel at only 22” and would put a 6” bloop tube on it if iron sights where to be used. You couldn’t complain about accuracy out of each rifle.

That being said all of the 10/22’s and a toggle action PWS T3 I’m putting on 18” barrels. Again the short barrel isn’t hurting anything accuracy or velocity.

Also failed to mention on here when your talking velocities you are not mentioning anything about actual bore and groove sizes and the type of chamber being used. That will effect your velocities as well.

Later, Frank
Bartlein Barrels

 

[flatlander]

I don't care for the appearance/proportions of 16" bbls on most .22 rifles I've seen; for my tastes, a 22" bbl 'looks' better. So I don't worry about any of the minor theoretical gains or losses in velocity based on the old supposition that most .22RF ammo is loaded with powders that will be completely burned within the first 16" of bbl length. Maybe that's true today - or maybe not. I do know that a CZ455 Precision Trainer with 16" bbl in Manners stocks produces considerably louder report than those with 20"-24" bbls. Krieger says their .22RF bbls are taper lapped, so it shouldn't make much difference where you finish the muzzle. Having done four Kriegers for my own rifles, and finishing all four at 22", I'm not seeing any obvious differences in accuracy between them. I spoke with one of the guys at Bartlein about .22RF bbls a year or so ago while placing an order for a .224" CF bbl, and he kind of scoffed at what Krieger had told me about their .22RF bbls... All I know is that the Kriegers I've done for Stiller, 40XB, and V-22 repeaters shoot just as well as the 22" Bartlein that Vudoo installed on my 2nd V-22...

 

[Hi-NV Shooter]

I don't care for the appearance/proportions of 16" bbls on most .22 rifles I've seen; for my tastes, a 22" bbl 'looks' better. So I don't worry about any of the minor theoretical gains or losses in velocity based on the old supposition that most .22RF ammo is loaded with powders that will be completely burned within the first 16" of bbl length. Maybe that's true today - or maybe not. I do know that a CZ455 Precision Trainer with 16" bbl in Manners stocks produces considerably louder report than those with 20"-24" bbls. Krieger says their .22RF bbls are taper lapped, so it shouldn't make much difference where you finish the muzzle. Having done four Kriegers for my own rifles, and finishing all four at 22", I'm not seeing any obvious differences in accuracy between them. I spoke with one of the guys at Bartlein about .22RF bbls a year or so ago while placing an order for a .224" CF bbl, and he kind of scoffed at what Krieger had told me about their .22RF bbls... All I know is that the Kriegers I've done for Stiller, 40XB, and V-22 repeaters shoot just as well as the 22" Bartlein that Vudoo installed on my 2nd V-22...

I am currently using a 28" Benchmark on my Falcon, originally started as a 1.200 radius taper to .850 I had the smith turn the chamber end down to 1.00 so it would hopefully open the bore up slightly. Benchmark does not taper lap or try to induce a choke, they go for a consistent bore from one end to the other. this barrel is a shooter

Lee

 

[Bart B.]

I don't think a longer rifle sight radius helps.

A master class smallbore prone shooter can hold the LOS inside a half MOA area on 100 yard targets.

With a 24" sight radius pivoting on the rear sight, the front sight moves about inside a .0033" diameter circle. LOS on target moves about inside a .500" diameter area @ 100 yards.

With a 36" sight radius pivoting on the rear sight, the front sight moves about inside a .0050" diameter circle. LOS on target moves about inside a .500" diameter area @ 100.

This assumes the front sight is flanged to have the same visual angular clearance to the rear sight aperture edge for each radius. And the front aperture size has the same clearance to the bullseye. Aiming eye and sights are all centered on one parallax free LOS axis.

If visual target clarity with shorter or longer radii is an issue, a diopter lens in the rear sight helps. The eye must focus on the front sight. Use the smallest rear aperture possible for ambient light to sharpen target image.

If the half MOA LOS spread center pivots at the buttplate, the sight radius pivots 12" longer. The front sight moves around in a proportional greater area and the angle stays the same. The rear sight now moves around a half MOA diameter area 12" forward of the buttplate and the front sight 36" or 48" forward.

The aiming eye discriminates only angular errors aligning it, sights and target on the LOS. And you have to hold still 50% longer after the primer fires going from an 18" barrel to a 27" barrel.