Question about sloooooow 22Mag barrel twist. Maybe somebody in the biz knows why?

[VaniB]

Looking over some old targets, this question had bothered me for quite awhile; 14 years ago I bought a Marlin VLS stainless heavy barrel 22mag laminated stocked rifle. I had the action professionally bedded, put a 24X scope on the rifle, and installed a 1Lb trigger. I was hellbent on getting tight 5 shot groups even if it meant handloading 22Mag ammunition, and THAT is what I did. (no lecture today please about the dangers of reloading rimfire ammo. That is not the topic.) The results were 5 shot .25" groups at 50 yards. However, I was quite disgusted to find out that I could not shoot 1" MOA groups at 100 yards with this rifle. I had no problem shooting some 1/4" groups @ 100 yards with my other custom rifles. I'm a target shooter, and because I don't hunt there was no reason for me to keep a rifle that fired scattered 1.5" groups at 100 yards. I was heartbroken and disgusted when I dumped it on GunBroker for a giveaway price. I really made that hog-hunter in Florida who bought it very happy! He received the rifle and later told me that he thought I was a scam when he saw the photos of what I was selling for so cheap!
ANYWAY,
The conclusion I came to was that the 1-16 twist in this barrel was not fast enough for the 100 yard distance. Could a gunsmith or somebody in the business of producing barrels, tell me for a fact why such a ridiculously slow as crap twist like the 1-16 is still used in the 22Magnum? It is NOT like the 22mag cartridge is shooting a bullet at such blistering speeds that a sensible 1-12, or even a slow 1-14 twist couldn't be used. It's not like the bullets will spin apart or that such tremendous breech pressures will develop. I'm sure had the barrel been a 1-12 twist (or maybe a 1-14), I've still have had the same .200" groups at 50 yards, but been shooting 5 shot 3/4" groups at 100 yards too.


Photos are of 5 shot, 50yard targets.

 

[B23]

Most 22 RF bullets have the shape of a semi pointed bowling ball and they don't really require a very fast twist. To spin them faster than is necessary to stabilize the bullet would be pointless.

 

[Ned Ludd]

If a rifle's twist rate is sufficient to gyroscopically stabilize a bullet at some shorter distance "X", the bullet will generally be even more gyroscopically stable at some longer distance "Y" (as long as it falls within the useful range of the cartridge), because a bullet's linear velocity falls off much faster than its rotational velocity. As a result, gyroscopic stability actually increases with distance. It seems plausible that the poor precision at 100 yd versus 50 yd might be due to some other factor besides a too-slow barrel twist rate and gyroscopic instability.

 

[MrMajestic]

Nedd speaks wisely...

 

[VaniB]

If a rifle's twist rate is sufficient to gyroscopically stabilize a bullet at some shorter distance "X", the bullet will generally be even more gyroscopically stable at some longer distance "Y" (as long as it falls within the useful range of the cartridge), because a bullet's linear velocity falls off much faster than its rotational velocity. As a result, gyroscopic stability actually increases with distance. It seems plausible that the poor precision at 100 yd versus 50 yd might be due to some other factor besides a too-slow barrel twist rate and gyroscopic instability.

I'm 66 and seem to recall that every rimfire rifle I've ever read reviews about over the years including the 22mag and 17HMR was tested for 50 yards. Some authors also fired the test rifles at 100 yards or more during the review, but the official final reports that the American Rifleman, Shooting Times, Rifle Shooter, Guns&Ammo, etc, always fixated on a 50 yard test.

I appreciate you trying to help, but it logically makes no sense to me that a slow 1,995 fps bullet intended for 50 yard shooting spinning at the slowest 1-16 twist, will maintain the same stability at 100 yards as the bullet speed and rotation diminishes after passing the 50 yard sweet spot. It DOES make much more sense to me that if you started with a 1-13 twist or a 1-14 twist, the bullet will slow down naturally to 1-16 rotation speeds as it reaches 100 yards. (helping to maintain accuracy as it reaches 100yds) If a Remington 700 in 223 is 1-12 twist, the 22-250 is 1-14 twist, and a Colt #6721 AR15 is 1-9 twist (all intended for light 55gr bullets), I can't imagine 1-16 being premium for the slow & lumbering 22Mag, and why a 1-12 to 1-14 would hurt.

 

[squint-n-squeeze]

I think the reason you see rimfire accuracy listed at 50 yards is twofold:

First, most people use rimfire for shooting in pretty close. It's a small, light bullet that's a bit more powerful than an air gun.

Second, they are very susceptible to wind. You have to be super careful not to pick up wind movement at 100 yards.

How many types of ammo did you try? If you're trying to get that kind of accuracy with a rimfire, you'll need to try out a buttload of different manufacturers. And all the comments above, about stability and the shape of a RF bullet, I would tend to agree with. Not saying you can't shoot RF at 100 yards - we do it all the time at the silhoutte range to knock over steel. But if you're looking for benchrest accuracy, you might want to consider a different cartridge.

 

[JohnHenry]

Lilja's 22WMR barrels are 1 in 15" twist and the Ruger American Rimfire 22WMR barrels are 1 in 14". If building a custom 22WMR one has many barrel twist rate choices as the 22WMR groove diameter(.224) is the same as 22 centerfire barrels.

 

[Knotwild]

I see you were using bullets that appear to be designed for use in center fire rifles (noted on your target). They probably were designed for common center fire twists and are longer than a factory 22 mag projectle.

Add to that the fact that Marlin probably didn't invest much in barrel quality for a $200 gun and the fact that the button could have slipped when pulled through rim fire grade barrel steel; and the result is a barely stabilized bullet that gives up stability as it passes 50 yards.

 

[AWS]

In discussions on the 22 Mag over at RimfireCentral lot numbers have a lot to do with accuracy. I suspect that that priming compounds have a lot to do with accuracy in the 22 mag not barrel twist as there are a number of 22 Hornets with 1-16 twist that are very accurate.

I don't think the 22 mag was built to give you longer distances over a 22 LR but just to give more power at the same ranges. The 22 Mag takes you out of the rabbit and squirrel group into the fox, cat and coyote size animals.

My 22 Mag is quiet, perfect for more populated or firearms restricted areas for calling preds, it will do 1 1/2" with Win 40gr Jacketed HP's and that is more than enough for close in work for up to coyotes.

60 yards with CZ 22 Mag.

 

[XTR]

As you note, reloading RF ammo is not a common practice, and based on what is written on your target you are using a bullet for which that the rifle was never designed. It's a center fire bullet. I'll wager that it's quite a bit longer than the standard factory bullet offerings.

The rifle was designed to stabilize factory 22WMR rimfire bullets, which are short and round. It has plenty of twist for those. If you want something faster you should call Dan Lilja, he makes RF barrels in different twists.

 

[Ned Ludd]

...I appreciate you trying to help, but it logically makes no sense to me that a slow 1,995 fps bullet intended for 50 yard shooting spinning at the slowest 1-16 twist, will maintain the same stability at 100 yards as the bullet speed and rotation diminishes after passing the 50 yard sweet spot.

It may not make sense to you, but that is exactly what happens. It has been established beyond question that bullet linear velocity decreases much faster than its rotational velocity through the normal course of its trajectory. It makes perfect sense if you think about it. Drag due to the shape of the bullet as it moves through the air is what slows its linear [forward] velocity relatively quickly. However, the bullet is round and symmetrically-shaped around its long [rotational] axis, so what is there to stop it from spinning? The answer of course is also drag, but due to its symmetrical shape around the long axis, the drag force that counteracts a rotating bullet is far less than the drag force against linear movement.

Here's the reason I posted this information: you may spend considerable time and effort going down a rabbit hole trying to find an explanation for your observations that is directly linked barrel twist rate. It's also known as bias. Unfortunately, if the twist rate is not the underlying cause, as I suspect it isn't, that time and effort will have been wasted. Just a consideration. I hope you find the information you're looking for.

 

[Zero333]

Never seen a accurate 22mag at 100yards/meters because there is no top notch 22mag ammo available.

22lr on the other hand has Lapua Center-X, RWS-50, Eley-Tennex among many others from those manufacturers are extremely accurate ammo off the shelf. Thus making 22lr THE better choice for target shooting small groups at 100 yards.

 

[XTR]

If your 1900ish FPS number is correct looks like your reloads may be supersonic at 100, but if it's a little less than that then transonic disturbance may also be a part of the problem you're running into. It's one of the reasons that a 22WRM won't shoot as well as a 22LR at longer ranges, and why all 22LR match ammo is subsonic.

 

[Carbide]

VaniB
Best shooting 22 mag will have centerfire bore and groove dimensions. Take off burnt out for 4 " 22-250 bbl and cut off 5" 14 twist or new barrel will get it going. Check the bullet diameter on factory jacketed ammo. 22 lr barrel is .222 groove and .217 bore +-. Ammo of choice before I gave up and was no longer available because of lawyers was RWS. The original stuff was 2100 fps 40g hp, new is 1900 fps and never shot as well. New 35g tipped bullet loads are pretty good.
Carbide

 

[VaniB]

Lilja's 22WMR barrels are 1 in 15" twist and the Ruger American Rimfire 22WMR barrels are 1 in 14". If building a custom 22WMR one has many barrel twist rate choices as the 22WMR groove diameter(.224) is the same as 22 centerfire barrels.

Thank you, John Henry. I can't imagine those twist rates being a problem.
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I guess it was not obvious to some folks here that the reason why I handloaded my own 22mag ammo was because the many different kinds of factory ammo I tried was worse then anything I handloaded. (all benched with 3 wind flags.)

As said in line 1, the rifle's gone 14 yrs now. At the time I was merely trying to duplicate the performance of my Remington 5mm rimfire I bought as a young man in 1976 for $75 and have long missed. That 5mm fired 5 shot 3/4" -7/8" MOA at 100 yards. (not interested in owning a 5mm centerfire conversion thanks) But not being a hunter, rimfires have no advantages for me over small centerfire cartridges and are now out of my system. I don't ever care to shoot a rifle again that I must rely on factory ammo. This thread was to muse out loud that I never understood why my 22mag Marlin couldn't shoot 100 yard MOA, and that I suspect a 1-14 twist might have made a difference. Couldn't have hurt.

 

[JohnHenry]

Thank you, John Henry. I can't imagine those twist rates being a problem.
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I guess it was not obvious to some folks here that the reason why I handloaded my own 22mag ammo was because the many different kinds of factory ammo I tried was worse then anything I handloaded. (all benched with 3 wind flags.)

As said in line 1, the rifle's gone 14 yrs now. At the time I was merely trying to duplicate the performance of my Remington 5mm rimfire I bought as a young man in 1976 for $75 and have long missed. That 5mm fired 5 shot 3/4" -7/8" MOA at 100 yards. (not interested in owning a 5mm centerfire conversion thanks) But not being a hunter, rimfires have no advantages for me over small centerfire cartridges and are now out of my system. I don't ever care to shoot a rifle again that I must rely on factory ammo. This thread was to muse out loud that I never understood why my 22mag Marlin couldn't shoot 100 yard MOA, and that I suspect a 1-14 twist might have made a difference. Couldn't have hurt.

Agree 22WMR ammo can be frustrating. A number of years ago I sold two nice 22WMR rifles because of frustration with the accuracy of the factory ammo. Sold an H&K 300 and a Cooper/Anschutz where Cooper stocked and supplied the bottom metal for a model 54 Anschutz barreled action. The Cooper was an honest 1 moa rifle at 100 yds but only with the now long discontinued Federal Premium ammo loaded with 30 gr Sierra bullets. A few years ago I did buy a 22WMR Ruger American Rimfire when Cabelas was giving them away for $180 prior to closing of the Bass Pro acquisition. The Ruger will shoot 0.9 moa at 50 yds using the Hornady/CCI 30 gr V-Max load and the Remington 33 gr load. As noted earlier, the Ruger has a 1 in 14" twist barrel. Bore scope inspection of the Ruger barrel looked very good.

 

[ebb]

I have an older marlin just like you are talking about (walnut stock. blue steel barrel) tried every factory load I could find. Armscorps Precision 22mag ammo was the best buy a long shot. Never tried it out to 100yds but sighted it for 75 and could do a 5/8s group.

 

[Hohn]

16 is standard .22lr twist. Why would it be inadequate for similar bullets at nearly twice the speed?

I didn’t see you post anything about bullet weight. But I’ve gotta think that if a 16 twist was inappropriate for .22wmr, it would have been discovered by now.

It seems rather more likely the defect is not the twist rate.

 

[VaniB]

16 is standard .22lr twist. Why would it be inadequate for similar bullets at nearly twice the speed?

I didn’t see you post anything about bullet weight. But I’ve gotta think that if a 16 twist was inappropriate for .22wmr, it would have been discovered by now.

It seems rather more likely the defect is not the twist rate.

I'm suspicious that 1-16 twists are chosen for both 22LR and 22Mag because they are often soft lead, or very lightly plated or thinly jacketed bullets that could foul rifling easier at faster twist rates. (??) Plus we already discussed that rimfires are normally hunting or utility based shooters intended for 50 yards. Heck, a spitball with a 1-25 twist could handle that short proximity, so a 1-16 should be able to do that. But firing tight 2's and 3's clusters at 50 yards with mediocre 1.25" groups at 100yds never made sense to me....unless the twist just was too slow beyond 50-75 yrds. I never owned anything else that grouped so paradoxically. Whatever I had firing 1/4" 5 shot groups at 50 yards had ALWAYS managed to keep sub 1" groups too.

 

[VaniB]

Agree 22WMR ammo can be frustrating. A number of years ago I sold two nice 22WMR rifles because of frustration with the accuracy of the factory ammo. Sold an H&K 300 and a Cooper/Anschutz where Cooper stocked and supplied the bottom metal for a model 54 Anschutz barreled action. The Cooper was an honest 1 moa rifle at 100 yds but only with the now long discontinued Federal Premium ammo loaded with 30 gr Sierra bullets. A few years ago I did buy a 22WMR Ruger American Rimfire when Cabelas was giving them away for $180 prior to closing of the Bass Pro acquisition. The Ruger will shoot 0.9 moa at 50 yds using the Hornady/CCI 30 gr V-Max load and the Remington 33 gr load. As noted earlier, the Ruger has a 1 in 14" twist barrel. Bore scope inspection of the Ruger barrel looked very good.

LOL.....Thanks. The frustrating range test memories are all coming back now!!! ...lol. This rifle did really good at 50 yards with Remington Premier 33gr V-Max Green Tips. Then, production was moved from overseas to the USA and the ammo now had a Tan Tip instead of a green tip, but fired poorly. So then I continued experimenting with other kinds of ammo and found that the Winchester 34gr Supreme ammo shot as well as the Rem Green Tip. So what the heck happens then?.....the frigging factory burns down and I can't get the ammo any more! That's when I started handloading 22mag using Sierra bullets to get the best accuracy. But, nothing ever did deliver 1" MOA at 100 yards. Mind you I had already suffered years earlier that my Remington 5mm rimfire ammo was permanently discontinued. That killed my favorite $75 rimfire rifle which did shoot 3/4" MOA at 100 yards.

With all that fiasco, NO MORE RIMFIRES FOR ME.