Unusual 30 cal bullet

[RCS]

I found this bullet in a box of old cartridges, it is .308 dia and is a jacketed soft point and the weight is 330 grains with a lead core. Some collectors say that Winchester may have produced such a bullet back in the 1930's ? other claim that Ernest Hemingway wrote about hunting big cats with a 30 cal that used a bullet of 340 grains !

Anyone seen a bullet like this ?Attachment 17201Attachment 17202Attachment 17203Attachment 17201Attachment 17202Attachment 17203

Information

Warning: This is a relatively older thread This discussion is older than 360 days. Some information contained in it may no longer be current.

[Gibbs505]

Wow, that should have some deep penetration! Not much powder behind it though.

[RCS]

I just used a 30-06 case that I cut the side off to show the bullet. I don't know what cartridge was used with this bullet but early cartridges like the 30 Newton or 300 H&H could have been used ?

[old crow]

Reminds me of the 170+gr 7mm style bullets used early in the 1900s when brave souls shot elephants with them in solids. I love big, long, slow and heavy old bullets. Thanks for showing it.

[Kirk]

That bullet would need a very quick twist, maybe 1:7" vs. the regular 1:10". That implies a special barrel as well - a custom outfit.

[smellie]

It does look to have been in a cartridge for some time, then pulled. The lead on the tip is degraded (oxidised) significantly; this one wasn't made last week.

I'm thinking about twist right now. The .303 stayed at a 10-inch pitch right from the beginning to the end, and that includes the first 22 years, during which it used a 215-grain RN bullet. The .303 only starts becoming touchy when you load something lighter than a 150, so that is a lot of leeway. And, thinking on that original 215, they would not have put a rifle into the field which was only marginally stable: they would have wanted something as stable as they could get it. So, the question becomes this: how much heavier can you go before you start losing stability?

The M-14 uses a 145 - 147-grain bullet and has a 12-inch pitch, but guys are regularly shooting 190s in matches and getting away with it.

The .30-06 used a 10-inch pitch mainly because the .30-03 used a 10-inch pitch and they saw no reason to change. But the .30-06 was supposed to use a 150, later a 152, then in the M-1 cartridge a 173, then it used a whole big pile of AP and Tracer and so forth, most of it in the 168 area. And some Match .30-06 was loaded with 180s and you can buy it today loaded with everything up to the old 220. How much heavier can you go with the '06.... and still have something stable?

Answer: I don't know.

Fred Jones and Sir Charles Ross got up to some very strange things with bullets, including the Ross "Needle Nose" 215 for the .303 and the famous Ross "pencil" bullet. Charles Newton hung around with that crowd and they swapped ideas back and forth pretty freely. I can't find anything on Ross coming out with a .30-330, but I'm thinking that the earlier post, suggesting Newton, might bear some looking-into.

There is still some weird stuff out there to be picked up. I even got a .28 Ross cartridge a few years ago. They are not common; only 1 rifle still exists, from what I can discover. So why not something else from that period?

What do you gentlemen think?
.

[old crow]

The cartridge/bullet shown would require a very unusual magazine but a shorter cartridge would have very, very limited powder capacity. ? Is this a bullet for a single-shot or double rifle?

[Cosine26]

*The bullet looks very much like one developed as the “Cutie” (for quick twist = QT) a wildcat developed I 1947 or 1948 and described in an American Rifleman magazine in that time frame. It has been a long time since I read that article but as I remember it the “Cutie” was either a 6mm or a 6.5mm not a thirty caliber.
*Twist required for stability of a bullet is more dependent upon the length of the bullet in relationship to the caliber. The Greenhill Formula as developed for lead bullets (SPG of 11) can be used fairly satisfactorily for bullets having a SPG of 10.9 (most present day bullets.) Using the Greenhill formula the 220 grain bullet as used in the 30 Krag and the 30-03 requires a twist of 9.9”. The ordnance department selected a 10 “TWIST. When the 30-06 (150 gr) bullet came out there ws no reason to change. This was a fortunate choice for while the 150 gr bullet is over stabilized the 10” twist works well with the later M1 bullet and the various 180 gr boat tail match bullets.
*When Winchester introduced the 243 Winchester, and Remington the 244 Remington, Winchester opted for a 10” twist and Remington chose a 12” twist. Both worked satisfactorily with the 85 grail bullet but the Remington failed to stabilize the 105 gr spitzer. It would: however, stabilize the 105 gr round noise for it was shorter.
*The notation “S” for stability is a dimensionless number for stability. Theoretically an S = 1 should prove satisfactory but empirically it has been proven that S = 1.5 is the minimum satisfactory stability factor. It should be noted that temperature has an effect. The varmint shooters used a 14” twist in their 222 rifles. When the army tried the 14 “ twist in the AR -15 it found that at lower temperatures it was unstable therefore the change to a 12 “ twist which gave the M193 5.56 bullet a stability factor of 1.54 in lieu of the 1.13 stability factor of the 14 “ twist.
*Common stability factors are:
30 M72 Match- 10” twist- 1.90
30 M2 Ball- 10" twist- 3.42
30M2AP- 10" twist- 1.42
7.62 M59- 12” twist- 1.5
7.62 M80- 12" twist- 2.43
30M72 - 12 “twist- 1.3
*I am sure that there are newer and more scientific methods of determining the proper twist than the Greenhill Formula.
*Of the four accuracy factors affected by twist, three favor a looser twist but the stability factor favors a tighter twist.
For what its worth

[Chickenthief]

Given that the 30-06 casing is 63mm long the bullet is @50mm

Greenhill says: T = K x (D x D / L)
T = Twist
K = 125 for bullets under 1500fps, 150 between 1500fps and 3000fps and 180 for bullets faster than 3000fps.

So
(.308 x .308 /2) x 150 = 7.1

That's almost threading!