Most if not everyone who enjoys practice shooting with a .22 rifle knows how accuracy can differ significantly between different brands of ammo. Today I learned that's also true for different loads made by the same manufacturer.

All the shots taken at the target below were from the same Remington 597 rifle at distance of 50 yards. The hits that appear inside the hand-drawn circle were made with CCI Mini-Mag Ammo, while all those outside the circle were made with CCI Stinger ammo.

Not being an expert shooter, I can only speculate the lighter Stinger ammo is simply too fast for my 597 barrel.

Also, it came as no surprise that Remington brick ammo, which is very comparable to the CCI mini-mag in weight and velocity, performed almost as good as the Mini-Mags.

Dan, Do you know the difference in match loads and cheap promotional loads with some manufactures?

test selection for accuracy. As they are making a run of ammo some along the way will be more accurate than others in the production run. They pull samples and when accuracy it within X parameters it goes in the Match ammo boxes and they stop putting that run in those when accuracy dropps off during their testing.

In the 3 most accurate 22s I have owned the most accurate ammo I fired in them was all from one brick of PMC Zapper ammo. Of course I could not find any more of that lot number and it might not have lived up to that one brick.

Stinger ammo is a unique one in the 22 world and most of the time one of the least accurate but sometimes that doesn't hold up either. The Stinger is a stretched 22LR rifle case that cn hold more powder with a 29gr hollowpoint bullet (Think 22 Short) so velocity can be higher with more powder and less bullet weight. THe bullet does not have nearly as long a bearing surface to contact the barrel as a standard 40gr LR bullet or 38gr LR Hollow point bullet.

The bullet is simply too fast to catch the rifling and performs somewhat like a mini-ball in a smooth bore musket.

WOW!

That part about the Stinger not having enough bearing surface is a theory on my part though. Same basic bullet shoots quite well in the CCI Short Hollow point loads but not so well in the Remington 552 and Winchester 9422 and Winchester 62A that I had all of which are listed on the barrel for Short, Long or Long Rifle on the barrel. It has been years since I played with those and the Shorts and Stingers but IIRC the Stinger groups were about twice the size of the shorts or Long Rifle standard ammo. the Stinger ammo is sending the same basic bullet out at about 500 to 700fps faster than the short loads

The part about test selecting ammo for accuracy is from several sources including a Federal ammo rep and a guy that shot for Winchester years ago.

someone doesn't understand how rifling works and how barrels are spec'd

It's impossible for the "bullet to not catch the rifling" assuming you're sending a correct bullet it down the bore.

I'll attempt to put this in layman's terms...if you buy a 6mm (I'm using this because I know the exact numbers off the top of my head, I don't on a .22 bore) barrel, the barrel is .243 which means the "loosest part of the barrel" (aka grooves) are .243 then the "tightest part of the barrel" (aka lands) are either .236 or .237 depending on which barrel you buy. Bullets have a pressure ring on the back of them that are normally about .2432-.2434.

There is no way a properly sized bullet can pass down a bore and not "catch" the rifling no matter how fast or slow it's going.

Obviously any bullet of the proper caliber that travels down a rifled barrel is going to develop a given amount of spin. I'm sure there were those who recognized my description was not meant to be taken literally but as an exaggeration to describe how cartridges of different bullet weights, powder charge, and construction perform differently in the same barrel. Of course, those who reload their own bullets are fully aware of the challenges in finding the right velocities to get optimum accuracy from a given bullet when sent down a given barrel .

I've found the same performance difference with my Winchester Model 70. It performs noticeably better with 100 grain (25-06) bullets than with 120 grain rounds.

I suspect you're spot on. As you described, Stingers do have the appearance of being the smaller .22 Short bullet pressed onto .22 LR casing.

Your 25-06 shoots 100 gr better than 120 due to twist rate in relation to bearing surface length.

But at no point is a bullet not engaging the rifling.

Agreed. I should have included the words "as if" in my earlier description for those who couldn't recognize the point being made, that the two bullets achieve a much different spin when traveling down the same barrel.

Nope, that still doesn't fix it.

The two rounds achieve a much different spin, with the Mini-Mag achieving a more consistent and accurate spin than the Stinger.

Now personally, I find the much more scattered pattern of the Stinger to be about what you might expect from an unrifled barrel.

That's called bullet stability and normally bullet speed actually helps with bullet stability rather than hurts it...especially if your "under twisted". If you're over twisted bullets come apart and if you're under twisted you get some real weird stuff going on like key holing and the like.



For the record...you can add "as if" anywhere in that statement and it just simply isn't true.....ever.

^^Right Judd.

Don't spin one enough, and it is unstable. Spin one too much, and it is over-spun, and will shoot like crap. Even if it is not spun enough to come apart in flight. More than once have I seen a bullet too light (too short) for a twist rate made agressive enough for a longer bullet. The light (short ones) scatter all over paper.

Again, NEVER do they not catch rifling, and skip down a barrel, NEVER.

Shoot me for my loose choice of words. But please do so with an unrifled barrel so I'll have a better chance of getting away.

Is it the length of the bearing surface? or the length of the projectile?

I’ve shot CCI Stinger ammo out of a lot of guns, both rifle and pistol. Haven’t found one yet that shoots it good. Have heard rumors of guns that shoot it well, just haven’t seen it personally.

I could see where a lighter bullet with too much charge behind it and less surface area (as well as softer metal) might actually result in less spin as it contacts the rifling for a much shorter duration due to the increased velocity.

Please see my other post and thread in the Rifles, Shotguns, and Handguns section for a more focused discussion on twist rates.

My example of short and Stinger, the bullet is a 29 grain soft lead that you can indent it with finger nail. With a bearing surface of .07 to .08 which is less than 1/3 of total length with smaller diameter sections of the ogive and heel on either side of the bearing surface sure shoots better in my rifles so chambered and a TC Contender when going at 900 to 1080fps than it does at 1650fps.

The rifle and pistol I remember shooting Stingers very well had what looked like deeper land to groove depth. One thing about stingers with the soft hollow point bullet at that speed they do not hold together well. Some day I might try milk jug with water at a distance and try to get a hit at say 200 yards to see if there is some smearing of the rifling viable on the bullet.

Handguns I have had that shoot Stingers pretty good are an old RG single action but it has a fairly large barrel cylinder gap so it might be slow enough with that and an 8 inch TC Contender barrel. The other one I no longer have was an old Winchester from i think the 30s that the lands looked taller than most other 22 barrels I have owned. The Winchester 39A I currently have you need to look hard at the barrel to even see the rifling and it shoots standard velocity well but stingers are more of a pattern from it.

Both, mostly bearing surface.

It is not time in the barrel. Any bullet will rotate exactly the same number of rotations from chamber to muzzle, in the same barrel.