30-06 imp and twist rate and land grooves

[Kurt L]

I have also posted this on the wildcat forum.
I am thinking about getting a 30-06 Ackley imp barrel made up for a 700 action I have.
Have not picked a maker on the barrel yet but this will not be till spring or so.

I plan on a 26 to 28" heavy varmint style with around 900-950 muzzle dia.
and plan to shoot 125,and 150 grain bullets and maybe 110 and or 130 but nothing over 150.
this will be a toy for shooting deer size game and smaller.and playen at the range some.

Anyway the twist rate all changes from barrel site to bullet site. like Berger says a 150 vld to use 1/14
twist others are 1/12-1/14 etc. I plan to use 150 grain or less in this and will never need or use any bullet above 150 grain.
Should I go with a 1/14 twist or a 1/13 twist for this to shoot bullets of 125,130,150?

Also any help on the lands?
I read the 3 groove are great and clean faster and stay cleaner than say 6 or 8 land barrels,
then I have read the 5r 5c etc barrels are great and shoot with less pressure etc?
thanks for any helpfull info you can toss my way.
 

[trotterlg]

Personally I would go with a 1 in 14 twist or even slower.  Best accuracy is gotten with a bullet that is just barely above stable spin rate.  Also energy is spent spinning a bullet up, it is debated about how much but it does cost velocity to spin a bullet faster.  The RPM of the bullet is what determins if it is stable or not, not how fast the twist is, so the 30-06 AI can make a light bullt spin real fast even out of a slow twist barrel.  The only time this will not work out is when the bullet drops below supersonic, and that will be far far down range.  I did a lot of expermenting with a 1 in 17 twist 22-250 barrel, it was great, 40gr bullets that were about 200fps faster than book out of a faster twist barrel.  You need to also consider that you are kind of on the edge of stability, so the crown and bullets have to be very good, a fast twist will hide a lot of problems and make things seem good when they really aren't.  Have fun, I did.  Larry

[Kurt L]

I found a cool download that dummies like me can use to calculate the bullet and twist rate.
The greenhill formula

http://www.z-hat.com/twistrate.htm

[Savage_99]

Kurt L,

At what ranges are you going to hunt at?  The bullets you listed seem on the short side for longer ranges.

As for that very heavy barrel are you sure that is what you want?  Its going to be so long and heavy as to be clumsy.

For the twist get something that will handle all bullets such as a 1-10 or 1-12.

I have 'Ackley Improved' chamerings in rimless, rimmed and belted rifles.   I just had to do it.   There is no real advantage to them.  It was just a hobby and I admit it.   I would never get another.

[Kurt L]

My blind is set up and I get around 300 max for shooting yardage.

This is not going to be until spring and sure is not in written in stone.
I reload and like the looks of the imp case and I know I will not gain much
from it just something dif.

I just go back and sit in my heated blind all day if deer hunting and this would not
be a gun that would be used to walk around with.It would be used for this and playing
at the range some.the long heavy barrel would not bother me.
why the long heavy barrel = my 243 with a heavy barrel shoots great.

As I said this is not 100% yet as I am also looking at the 25-06 imp with same heavy barrel
and 115 berger or 100 to 120 bullets with a 1/10 twist.

the one thing I am unsure on is the grooves lands ,I have read good reports on the 5r and
same goes for 3 groove anyone ?