260 gr 30-06 load data

[Ian]

Bullet yaw. Red outline indicates where the gas check went through. The turquoise line completing the elipse indicates the perspective of the complete base at the yawed angle. Looks like the sharp TC nose cut the small, clean, almost round hole in the middle.


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[Brad]

Well done Ian.
Excellent demonstration of how to read the bullet hole.

 

[Ian]

That bullet has a small differential between cg and cp, that's why I recommended trying a few with the noses HPd. Definitely would have gone for a tangent ogive rather than TC unless hollow-pointing. The Forster after-the-fact hp fixture can help sometimes. I suspect that's why I'm not the only one who predicted these would tumble easily upon impact, bullets shaped like this don't tend to be very stable unless you spin them very fast or remove some weight from the nose.

Edit to add one more comment on the pic, the crescent of the base smudge has a clean spot in the lower left, looks like the paper tore there and peeled back out of the way right when the nose punched through so it didn't get wiped by the body or base as it passed through. Some of the other holes have more complete crescent smudges from the bullet bases passing through yawed. The one singled out requires a bit more imagination due to the paper tear and resulting clean spot interrupting the witness smudge of where the base cleared through. Sometimes you have to study a bit to see what the target is really telling you.

 

[Josh]

Here is the stability of the bullet at 1900, is it possible the stability went up as the load got warmer? How fast do the TC bullets need to spin?

If i can get 3" at 100 yds i will be very happy, this is a hunting pill more than a target bullet.

 

[Brad]

Without a chronograph we have no idea how fast it was going. What is the stability at 1200 fps?

 

[Josh]

Without a chronograph we have no idea how fast it was going. What is the stability at 1200 fps?

 

[Ian]

If that's all the data input, the result isn't very realistic. Center of gravity and center of pressure are what we're talking about here, it's what allows the bullet to recover from yaw induced from exiting the muzzle. Tom Myers' ballistic program and a couple of others that come to mind account for CG/CP. An example is a .38 SWC and full-wadcutter of the same length. The program here, with the data fields shown, will calculate them to be virtually the same stability, but in reality the WC will start to wobble after 50 yards or so while the SWC, with CG behind the CP, will be stable until gravity pulls it to the dirt.

 

[sundog]

When I read OP my first thought was, 'ah, 35 Whelen, problem solved.'

Yes, it's not 30-06, but ya gotta know the limitations. That probably didn't help much, but it was what I was thinkin'.

 

[fiver]

go to 19 grs...
my longer boolits in the 0-6 seem to shoot a touch better with that.

OOOhh,,,and since Corky is here ask him for his 4227 load, he has a pretty good one he shoots.


and I'm smiling to myself just so you TWO know.

 

[Josh]

Thanks Lamar, i will load up some more 18 and some 19 gr loads. The bullet seems to want more speed, like i said, groups got better as the load went up.

 

[Brad]

The bullet got more stable if nothing else.

 

[fiver]

it'll take the speed.
it'd take more if the nose were shorter. [shrug]
but I seriously doubt more than 2,000 fps is gonna be needed to clean out a group of deer if you can get them to line up.