Someone gave me a recent box of .338/225 gr. partitions that lacked the crimping groove that those bullets have always had. In other words, they are smooth-sided bullets with no groove or cannelure, just like most smaller caliber partitions.

Lo and behold, they shoot a lot better from my gun! I just checked the zero yesterday for an elk hunt in a couple of weeks and found that three shots grouped into just about an inch at TWO HUNDRED yards. This compares to loads with the identical bullet from a previous grooved lot that shot about 1.5" at ONE HUNDRED yards.

Has anyone else found a difference in the grooved vs. ungrooved Noslers?

Interesting, I had just the opposite occur with my .338. The old style 250 gr. bullets with the cannelure would consistently run about 1" in my M70. I don't think I had adjusted the scope in 10 years, they always worked. 2 years ago I picked up a box and noted that there was no groove. When I got around to shooting them I thought my scope had gone out to lunch; I am talking 3.5" groups or worse. I found a few of the older ones and they were back to the normal 1". These are so bad that I was going to call Nosler and see if they had any good ideas but just haven't had the time. Right now I have a box of TSX's that I am playing with.
C.G.B.

My personal experience has been similar to "cgbac's". The old-style 250 gr 338 bullets are tack drivers in my rifles and have retained greater weights than the new Noslers. The bear in my avator pic was shot with my 338WM. One of the bullets recovered weighed 228 grs.

Which goes to show that each rifle is an individual. My prejudice tends toward bullets without cannelures, but obviously "your mileage can vary".

Stone

Nosler also made a two-diameter 338 bullet without a cannelure that was very accurate. Sort of a bore-rider. But regardless, what shoots best in your rifle is the best bullet made, as you already know and don't need me to tell you.

Ray

My recollection(could be wrong) is that the 250 gr. bullets with the groove were a 2 diameter bullet. In this process I found an old box with 5 of the really old semi-spitzers that were bronze colored and looked like they were turned on a screw machine. 5 of these went into 7/8" @ 100y. I did get around to chronographing the new ones and found I was getting about 100 fps higher average velocity (and pressures?) with very high shot-shot variations. I wonder why they changed?
C.G.B.

Different results could derive from where the bullet seats in the throat -- distance to the leade. Or possibly how the cannalure engages the leade.

It's possible that your neck crimp affects accuracy in the two different styles of bullet -- how the bullet releases from the neck.

And probably a combination of all these factors, and variations in the individual rifles.

I've had groups affected by a change in sandbag off the forend of the bench.

There are actually at least four different iterations of Nosler Partitions: (1) the original machine-turned jackets which had a rebate over the partition, (2) the drawn jacket version with a crimping groove (but not a rolled cannelure) (3) a drawn jacket version with smooth, uncannelured and ungrooved sides, and (4) same as #3 except with a rolled cannelure, these being produced for loading by various factories with production overruns sometimes sold to the public as "seconds".

To my knowledge, the .338/225 and .338/250 have only been produced in versions #2 & #3. My relatively better accuracy came with version #3 (smooth sides). So far as I know, version #1 was never made in .338, and while there may be some version #4's out there in .338, I haven't run across them.

I, too, had good success with version #1 (in other calibers). I've got to assume that it was dropped in favor of version #2 due to the high manufacturing costs of turning each individual jacket. I can't say why Nosler went from version #2 to version #3, or even if both versions may currently be available.

Someone mentioned crimping. I do not crimp my bottlenecked cartridges, which may be why the ungrooved version works better for me. If you crimp (and use the crimping groove) that may explain why you get better accuracy with the grooved version. Tengo rason?

Stone

Don't forget the 5th version. Made especially for the short necked 300 Win Mag, it had a series of notches instead of a single crimping groove, sorta like a screw-thread. I don't know if it was made in anything other than 308 but I used them briefly when I had a 300WM.

Ray

Correct! When Nosler used the machine-turned jackets, the rebate fell just about at the mouth of the then-new .300 Winchester case (at least when seated to fit into an '06-length magazine). So Nosler came out with the bullet you speak of made especially for the .300 Win. When they switched to the drawn jacket, the rebate and the problem went away, so there was no need for a special .300 Winchester bullet.

I'm sure that Nosler must have experimented with any number of variations that were never commecially produced. I had great luck with their "Zippedo" solid base bullets which had the tiny grooved bearing surface (maybe a little like the current Barnes Triple Shock). But so far as I know, the grooved bearing surface was never used on Partitions.