30-06 powders

Unclenick: For 30-06:

Rather than go through all the calcs etc, can you tell us what twist would be more likely to stabilize the 190 acu bond if its one that is on the stability edge?

And even with the newer bullets from Hornady and Sierra are we seeing a shift to say 175 gr norm for a 1-10 twist?
 
Well, the only way I can tell is to go through the calculations. You can too, though, pretty easily. Go to the stability calculator at the JBM site. At the bottom they have a gyroscopic stability estimator. You plug in the weather conditions and the muzzle velocity you will get and your twist. On the left of the screen is also a link to a list of bullet lengths to use with it.

In this case if I assume a 24" barrel and 10" twist and ICAO standard conditions, then this 1.46" long bullet, with what looks like a 0.15" plastic tip, gets a stability factor of 1.962, which is plenty stable. Anything below about 1.3 can begin to be an issue, and 1.4 or higher is wanted for match accuracy. Even dropping temperature to -40° and MV to 2400 fps, it still exceeds a stability factor of 1.5, so I think you are good to go. Go back to that calculator with your actual shooting conditions to be sure.
 
I do use H4831 in the 30-06 and I have had very good luck with it. I have used it for many years with the heavier 180 and 190gr. Hornady Interlock bullets that I still favor for hunting.

I have also used RL 22 with those same bullets and have always had excellent results with it. I never noticed any change in accuracy due to temperature variations.
 
Wendyj, what primer are you using?

I had wild velocity swings at low temps with large charges of slow burning powders in my .270WIN ....magnum primers pretty well cured that.
 
RL-22 is a very slow powder .....rework your load using CCI 250's and see if that does not solve the cold temp iregularities issue.
 
I've not used RL-22 ...... it is usually behind IMR7828 on the burn charts ..... and large charges of 7828 call for magnum primers, IME.
 
Rel#22 gave me fits. It was accurate enough, just too finicky between hot and colder temps. Loss of fps in cold temps difference in POI also. This was observed in my 25-06 and two 7mm RM's. Never tried it in a 30-06. H4831sc is what the 25-06 gets now and works great. Rel#25 for the 7mm RM's now.
Just some info for ya.
 
Wendyj

If you can stand the cold weather some more,
you might want to make several groups of 3-rds each,
step up each group of 3 by .01th gr,
using the same loading procedure as your summer time reloading.

Then shoot each load group to see what the results are,
you might find a perfect winter group/loading etc,
provided you are NOT up to the high pressure end of your rifle etc.

HtH,

Tia
Don
 
I thank everyone for all the replies. I've got ladder tests loaded up with 4 different powders. Only bad thing is it's back in the 70s again. Next weekend supposed to be back in the 30s so I am waiting for colder weather again.
 
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