For a minute there, Dave, I thought you were going to hold an exorcism. Begone, evil spirit of inaccuracy! Free this rifle from your icy grip! haha. Regards......

It's that .338 bad juju acting up again. I am allergic to it...

I have to think it has something to do with bullet construction, rather than any particular velocity. Rate of twist could also be a factor, although I doubt that could change much during a bullet's flight.

Divining the truth about a rifle and our abilities on the range is a joy the "extrapolators" will NEVER know.

You didn't say but I assume you were shooting handloads. I don't handload, but my dad did, and I remember him telling me that some primers can cause that kind of gradual vertical stringing at longer ranges. First couple of shots will be tight, but subsequent ones string out up or down. My immediate thought, though, was that the barrel was either beginning to overheat or become fouled. I know I had hell sighing in my .270 a couple of years ago until I finally realized that the temperature at the range on that August day was about 105, and the more frustrated I was becoming with the process the less time I was allowing for the barrel to cool. I put the gun up, took it home and cleaned it, went back on a cooler day and allowed twice as much time between shots. Like magic, the groups were tight again. The way I figure few mammals are going to stand around while you take more than three shots, anyway.

I wonder if the center of gravity of the bullet has anything to do that would cause this???

Were you shooting handloads or factory stuff? Were the targets shot with the same ammo you used when hunting? I wonder how much barrel harmonics had to do with the .338 printing so wide. In SW Kansas the wind is an almost constant factor and that's why I favor a heavier bullet when practical.

Couldn't have anything to do with the barrel being hotter than the first shot could it?

Dave-
Interesting to see what your results will be from your hand loads.

To All: I doubt very much if my worries are caused by bad bullets. These were Scirocco IIs, which I've watched being made at the Swift factory. They check them before they put them in the box. I doubt that, in the past 20 years, I've had an accuracy problem that was caused by flawed bullets. I have, however, seen plenty of flawed cases.

From what I've seen, if there is a flawed component, your accuracy troubles are going to show up at 100 yards and not wait for 300.

To Jim in Avon: That is some beard. But that's not important now. No, the low shots occurred at random. That rifle is bedded so well that I can take the barreled action out of the stock, screw it back together, and shoot into the same group.

To Happy Myles: I think that, generally, heavier bullets do much better at long range. This is the reason, as far as I know, that the military went to a 175-grain bullet for its match 7.62 rounds. When Kenny Jarret wanted a load for his dedicated 800-yard (plus) .300 Jarrett rifles, he opted for 190- and 200-grain slugs and a fast-twist barrel. By the way, since you have connections among the upper strata of British society, is farting allowed at Royal weddings?

Dave,
do you sight in for MPBR, or dead on at a given distance?

OK, I couldn't quite figure out your point of aim for the exercise,mostly because i read poorly, but would the 10" of drop caused you to miss your .338-size quarry? In other words, with your sight in distance and allowance (as you are fond of those "no guesswork" scopes) would you still have been in the vital zone?

Assuming a perfect shot, of course. Of course.

Dave,

Could you expand on why a bullet would destabilize after going only 300 yards? From all I know and all I've read I cannot think of why it would go unstable after that short of range. I personally doubt the bullet is going unstable at that range and feel it is more due to the load.

Dave: What scope do you have on the 6.5-284 ??

Ohh couple more? Dave
were you using corebond ammo? what grain?

Dave,
Please update us as soon as you get something. The .338 Win Mag has been my go to gun for years. I recently was at the range and the thing is amazing to 250 yards as in 1 inch 3 shot groups. Beyond that it can hit a pie plate but that isn't saying much. I have shot handloads and out of this particular rifle 225 Gr. Remington CL put a group on paper that any handloader would be proud of. Still haven't figured that out. I have a good friend that has the same issues beyond 200 with his 338. All he shoots are handloads. Both these rifles are Ruger MII 77 stainless

PS, that bullet is turning 2,870 rpm with a 1-12 twist

WAM I suppose one could consider shooting at 100 yard intervals practice as it certainly does provide plenty. Actually what I am attempting to accomplish is what my bullets are doing at those distances. Like DEP said some bullets destabilize over long ranges, many factors can be involved including the rifling of the barrel but usually the bullet construction and/or components. Regardless this is a matter of time, persistance, money, and experience. For this reason on my long range rifles once I establish an accurate and stable load which performs as I intend on game, I rarely vary from that combination. Of course sometimes for some reason things can go wrong and you get to start over again. I am not a long range competitive shooter but I do study what they do as this group seems to know much more about this subject than I do.

i prefer to reload so that i know it's done right. if not, it's my fault.

Am not a professor of ballistics nor a long range competitor. Do shoot a lot and use hard the 338. As have mentioned before have have owned four, and currently two 338s. You are an experienced and careful handloader using good components,so won't denigrate your knowlege. I have found at longer ranges working up with a bit heavier bullets in the 338 seems to usually get rid of this problem. Kindest Regards

I plan on working up some 338 Win loads in the near future, using both Swift A-Frames, and Alaska Bullet Works bonded 275's. I'll test them out to 300 and let you know what comes of it.
It looks like I'm going to have to change my handle. Pulling the plug and retiring from active-duty on Sept 1, 11 trips to the sand-box in the last 10 years is enough for me, just over 1000 combat hours and 700+ combat sorties.
I'm goin' home and I already got my watch set on "Talkeetna Time".
Hoping to score a brown-bear and a moose in the fall.

AKX for now.

I figured SC had something to do with the Royalty and we commoners were simply not privy LOL. Happy, my .338 is of the Winchester persuasion for the same reason as yours.

To All: Please excuse my absence, but the website would not allow me to submit. I was shooting a .338 Win Mag, handloads (210 gr Swift Scirocco), at 2,870 fps chronographed. I have no idea what the hell was going on. The first time I saw this was with a .300 Weatherby Magnum, and a day later I was talking with a couple of friends who are professional ballisticians, and they said it sounds like the bullets are destabilizing, but we're not sure.

There's nothing wrong with the rifle, and God knows there's nothing wrong with the .338 Win Mag cartridge.

To Chesney14: A Leupold VX-3 3.5X-10X.

To Big Boy 25: I don't even know for a fact that they are destabilizing. The only other thing I could think of would be a wild variation in velocity, but I weigh all my charges, and hardly ever see anything more than 25 fps variation. It could be that if I got them going faster, or slower, that might do it, but I think it's easier to switch bullets.

So, even as this is written, I am working up a load that will not fall apart at long range. I don’t like it, but it beats missing?

Load up some Hornady's and stop screwing around and stay away from those fad bullets. Hornady and Nosler Partitions perfect for the western hemisphere!

same kind of goofy phonomena with my 7wsm. shoots 160gr accubonds into tight groups at 100yds. then the groups open up at 200. from 300 on out to 500 this load shoots under minute of angle. even 200 yd groups are minute-of-elk though. strange things happen with different load combos. that's why we practice.

Coop,
Now I have never tried the Scirocco but there is a Scirocco II. Wonder the difference?

On a suggestion from Beekeeper, I tried some 225 gr .358 Accubonds in the .35 Whelen and got the best accuracy ever at 100 yards and pushing 2,700 fps, too. I fired some more today to verify velocity before removing the scope from the rifle for CDS modification. You can bet that I will fire some at 200 and 300 yards with the reworked scope prior to taking it afield in October.

Sounds like velocity variations from cases. Or something.

I like Del's advice of trying the uniform and slippery TTSXs or MRXs, but if you're confident in the Sciroccos, maybe not.

Didn't Barnes just come out with another long range bullet?

What I take away from the new Scirocco is that it carries better and that it's tougher. Have you shot anything with one yet?

Jim in Mo, don't know Sir the difference? Were I live now, I don't have the luxury of getting out like I did to test and research loads. I'll stick to what I know works the best for what I do.

The more I think about it, having a thinner/smaller diameter lead core in a ultra thick copper jacket I'm scratching my head how it can possibly remain stable at long range.

Like I said before, that bullet is turning 2,870 rps (Revolutions Per Second) or 172,200 rpm with a 1-12 twist!

After reading it all again, I think it has to do with either primer inconsistency causing irregular powder ignition or bullet concentricity / weight issues. I have only heard a few folks raving about Swift bullet's accuracy anyway. Were the cases weighed and trimmed to the same length?

Assuming you were sighted in at a 200 yard zero, you should be hitting -7.15 inches below point of aim. If I were zeroed at 200 yards , I would be more concerned with the "bullseye flyers" @ 300 yds.!

One thing to consider is that there seemed to be no issues at 100 yards, but only some of the 300 yard shots were skewed. The actual projectiles fired at 100 yards were not the ones fired at 300 yards. Same brand, same box, but not the same bullets.

Ishawooa

The 7mm Weatherby is a relative newcomer for me and the .35 Whelen is an old friend that has accounted for the majority of the game I have taken since I bought it in 1989. There are a couple of spots that I like to hunt in Colorado that seldom offer more than 200 to 250 yard shots. Other areas require one to "go long" or go to the truck. I have to take it out at least one day or it doesn't seem like an elk hunt.

One thing I have noticed in erratic results in accuracy, has been in older ammo. For some strange reason, the bullet seems to "stick" to some of the case mouths, and not to all...It might have to do with "sweat" or condensation inside the case on some that don't have a perfect seal. Whatever the reason, results improved when you set back the bullet a few thousandths, thereby breaking the "seal". Maybe storage conditions also have considerable variations for components, powder and primers, included....not to mention that simply some ammo is more accurate in some guns....