Suggested weight bullet for 30-06 with 1:10 Twist

[SerenityNetworks]

Yep. I ordered the Accubond for hunting and the Sierra Match for learning more on long distance shooting.

Everyone, thank you for all the input. I'm certainly keeping this thread in my favorites.

Regards,
Andrew

NRA Life Member
------------------------
"There are some ideas so preposterous that only an intellectual will believe them." - Malcolm Muggeridge

[Unclenick]

Jmbob,

OP said he's more interested in target accuracy than hunting, for which he will buy factory hunting ammo.

…And now that I've posted, I see he's already made the point. It also came up in the new Volume II issue 3 of Sierra's X-ring (not yet up on their site as I write this, but was in my email today) which has a photo of a MatchKing fired into 30 gallons of water, then recovered completely intact and not at all expanded.

[hooligan1]

My rifles like those Accubonds.

[noylj]

In general, 175-220gn.
In general, for an easily available bullet, a Sierra MatchKing.
In your specific case, you may find that your gun loves 150gn bullets or even lighter.
Guns and barrels march to their own terms and all we "know" is what weights a certain twist rate stabilizes best most of the time.
Twist rate still seems to be more art than science.

[FoghornLeghorn]

tagged for reference

[ms6852]

In my rifles the 165 grainers are the most accurate with sub moa groups at 200 yards. Good enough for deer and elk. As I have gotten older I now shy away from the heavy stuff.

[Unclenick]

6-year-old thread, so the original participants are mostly no longer looking.

For historical reference, the 10" 30 caliber twist was used initially in the 30-40 Krag for stabilizing 220 grain round nose bullets. The military just kept that 10" twist until the M14 was developed. It is more spin than is necessary for short bullets. However, most bullets of modern manufacture are better balanced (have better mass symmetry) than they did a hundred years ago, so spinning too fast no longer tends to lob them laterally off the trajectory and make them wobble badly in flight the way it once did. The main thing you have to watch out for with too much spin for a short, light bullet is core stripping, where the angular (rotational) acceleration gets so great the core slips inside the jacket, which deteriorates group size rather significantly. Light solids don't have that problem, though.

[cdoc42]

Here's a site you may want to investigate: jbmballistics.com

It lets you calculate the stability of your bullet, providing a Miller Stability Value that should be between 1.3 -2.0. The military uses 1.5.

It does not incorporate the BC value, just length of the bullet vs twist rate. I compared a Speer 145gr bullet with a Sierra 175gr bullet and plugged in various velocities. Twist rate is 9.5" in .284 caliber

145gr, .284" bullet 1.188" in length

2900 fps = stability value = 2.193
3000 fps SV= 2.244
3100 fps SV = 2.269

175gr, .284" bullet 1.5" in length:

2600fps SV = 1.309
2700fps SV = 1.326
2800fps SV = 1.342
2900fps SV = 1.358

[FoghornLeghorn]

Nick said, "... The main thing you have to watch out for with too much spin for a short, light bullet is core stripping, where the angular (rotational) acceleration gets so great the core slips inside the jacket.."

I have a box of 150 grain Sierras that mic right at .898" which means the phenomenon of which you speak is likely?

I should go heavier/longer? cdoc's recommended 175 grain bullets at 1.5" in length?

BTW, I'm using 4350 powder.

[Unclenick]

Harold Vaughn documented the problem in a 270 Winchester shooting, IIRC, 90-grain bullets. The SD would be about the same as a 110 grain bullet in .30 cal. So it was going pretty fast. I've not heard of this problem with 150's in the 30-06, though. So it's more commonly an issue with people loading light, fast bullets for smaller game or varmints.

The bottom line though is, if the bullets group tightly, it's not happening. Test and see. If you pass a certain load and your groups abruptly grow an MOA or two, and loading higher just makes it worse, it's a possibility.

[FoghornLeghorn]

Thank you nick.

Any suggestions as to starting load for 4350? It's for a recently acquired rifle so everything's from ground zero.

[jmr40]

A 30-06 with a 10 twist will do just fine with almost any bullet 125-220 gr. Maybe even heavier. It is really bullet length, not weight that is the determining factor, but generally speaking heavier is longer. Some longer 220-230 gr target bullets may be marginal.

I don't forsee any issues with the 150 gr bullets you're thinking about using at 30-06 speeds. A really hot load will be 3000-3050 fps. You'll probably be closer to 2900 fps. Now that bullet from a 10 twist in one of the 300 magnums at 3500 fps might be an issue.

Use this sight for some ideas.

http://www.hodgdonreloading.com/data/rifle

Which 4350? It does matter

H4350 is my go-to 30-06 powder for bullet weights 150-180 gr. Heavier bullets do better with slower powders. IMR4350 is similar in performance, but the load data is not interchangeable. I prefer H4350 because it is much more stable in temperature changes than most other powders.

Over the years I've loaded various 150-180 gr bullets for my 30-06 rifles with a near max load of H4350 with very good results. But it is best to start lower and work up. The exact bullet, primer and case can matter as well as individual rifles. Just because the max charges are safe in my rifle does not mean it would be in your rifle. Refer to the link for starting load data for the powder you're using

[Unclenick]

Looks like the starting loads are 54 grains for IMR4350 and 56 grains for H4350.