Rate of twist, and some bullets

bigbore14

bigbore14

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I am reloading for my Sako 85 300wm. Rate of twist is 1:11. The box of bullets I bought were TSX 200 gr. On the box there is a label that says, 1:10" twist or faster. Can I reload these? What should I be aware of? Or will they just not be very acurate? Thanks to all you for your great help so far in feeding these pigs, Dave
 
What you should be aware of is the stability of the bullet... I would only load up 5 and take them out and test them put the target 10 yards away and fire if your target results look like bullet going sideways thru the paper "keyholing" then your barrel can not stabilize the bullet and it will not work correctly. This is what happens when you try and fire bullets designed for a 1-8" twist thru 1-12"

The difference in your situation is not as extreme, if you don't get any keyholeing load up some more and test at 100 yards, 200 yards and what ever you plan on shooting...

keyhole.jpg
 
In my 7mmRM I use 162g A-Max bullets.
On the box it says 1:8 twist rating
My Rifle is either 1:9.25 or 1:9.5 (cant remember exactly)
They fly great and group great.

Your just going to have to give it and try and see
 
Try Greenhill's formula:
Twist = 150 diameter squared/Bullet length
It has always worked for me, and has usually been conservative. That is, usually even bullets a bit longer are stabilized.
 
Last edited:
Well I did up 5 different loads in one powder for it, and it worked great. At 100 yards the bullets were touching in some of the groups. Thanks a lot guys.
 
grouch said:
Try Greenhill's formula:
Twist = 150 diameter squared/Bullet length
It has always worked for me, and has usually been conservative. That is, usually even bullets a bit longer are stabilized.
Click to expand...

Greenhill formula does not work as well for solid copper bullets such as the Barnes offerings. Regards, Eagleye.
 
Stability increases as a bullet moves downrange, so if they are good at 25 yards, they will stay stable.

You are testing in cool weather. Stability will improve as the air warms. But a hunting bullet should be tested in cold air.

To see how much safety margein you have, load some with 3 grains less powder. if they are stable at 25 yards, you are golden.
 
Ganderite said:
Stability increases as a bullet moves downrange, so if they are good at 25 yards, they will stay stable.

You are testing in cool weather. Stability will improve as the air warms. But a hunting bullet should be tested in cold air.

To see how much safety margein you have, load some with 3 grains less powder. if they are stable at 25 yards, you are golden.
Click to expand...


Really good info.
 
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