22-250 keyhole

[SSL]

Actually I agree with your statement. I should have continued by mentioning the differences (length to weight) between our old bullets when compared to today's. You are correct that today's polymer tipped bullets (as well as hollow points) are longer per weight than comparable untipped and require faster twists in most cases. It is often difficult to remember that for many of us who were raised on spitzer or semi-spitzer designs.

 

[topclass2017]

following up on bullet lengths...I measured the lengths of various .224" bullets and here's what I found:

HORNADY
40g v-max: .688"
50g v-max: .780"
52g ELD: .795"
53g v-max: .830"
60g v-max: 0872

Nosler
55g Ballistic Tip: .808"

Interesting that the 55g Nosler is in between the length of the 52 ELD and the 53 v-max. Shows that weight and length are not necessarily correlated.

A previous conversation with Hornady validated twist rate is about bullet length, not weight.

 

[SSL]

As has been stated, bullet length determines twist. To take it to extremes, a .50-caliber round ball for a muzzleloader weighs about 170 grains and is best used with a 1-48" or slower twist. Try that twist with a 170 grain round nose in a .30-30 and you would have end over end tumbling darned near in the barrel!
Where mistakes have been made is in assuming all bullets are created equal...even by those of us who should know better.

 

[BoydAllen]

An interesting little data point came up recently when I ordered some Nosler 6mm 55 gr. BTNL (no lead) bullets. I thought that I might test them in one of my PPC barrels, but that is not to be. You see because of their granular copper core being less dense than lead, they are a lot longer than the lead core version... .930". But all was not lost, after checking with one of the Nosler tech's who told me that they require a 10 twist, I remembered my .243 fills that bill quite nicely. I should also mention that even though they do not have a BT, their BC is better than the lead core bullet of the same weight. If I remember correctly it is .288. In any case, going to the Nosler online data, the top velocity is just a smidge under 4,000 FPS, which makes for a pretty hot varmint combination for situations where the number of shots per day is relatively low. Oh, and I should have mentioned that their terminal performance promises to be somewhat like a hand grenade. If you are wondering why I am interested in lead free bullets, I live in California, a beautiful state with a terrible government. Previously I had run a small test with the .40gr BT lead free bullets in my .22-250 and the accuracy was the same as with lead core bullets. I found that no loading adjustment was needed. I used my usual seating depth, and the same powder charge that I would have chosen for the lead core version.

 

[KeithF]

The 55 vmax is flat base and shorter than the 53 vmax. I own a Savage 12 predator (12t) and have shot both. I prefer the 53 for shooting beyond 300. You can’t go wrong with either bullet. I haven’t shot the 52 eld and can’t come up with an explanation for the keyholing. It’s odd that the eld wouldn’t stabilize if the vmax would, given the eld is shorter. For reference, I push the 53 to 3700 FPS.