Twist rate vs barrel length

[drt]

Hello all,
I am curious: what have you found the best twist rate for .223 remington with a 26 inch barrel?
What about for 20 inch barrel? Shooting Black Hills Ammunition 75 Grain Match Hollow Point.
Same question for a .308 winchester. Twist rate for 26 inch barrel?
20 inch barrel? Shooting Federal Premium Gold Medal Ammunition 168 Grain Sierra MatchKing Hollow Point Boat Tail.
Thank you in advance!

[GaCop]

I'm shooting a 26 inch 1 in 9 barrel with the 75 grain and getting excellent accuracy. The standard 1 in 10 should shoot the 168 well. With shorter barrels, accuracy will most likely be the same but of course, you'll see a velocity loss somewhere in the area of 25 to 35 fps per inch.

[BrentWin]

Barrel length does not effect the twist rate needed for a particular round/bullet weight combo.

Here is a list of Fred Moreo's reccomended twist rates

http://savageshooters.com/SavageForum/index.php/topic,507.0.html

[possum1]

Haven't tried the 75's but my 1 in 9 20 inch shoot's 73's very well.

[Lefty Savage]

See I had a similar question. My 10FLP .308 1:10 twist barrel won't group 168 or 175's very well. It does well to get MOA. But my 155 Palma hand loads shoot sub 1/2MOA. WHY???? The other thing (which I'm not complaining about) is it seems to like the load just under published max.

[johndoe3]

Lefty,
Just at or near max you are usually hitting an accuracy node. There are also accuracy nodes further down from max for the 168gr and 175gr bullets. The traditional way to find them is to do a complete ladder test. However, you might investigate the new OBT (optimal barrel time) method of calculation if you have Quickload. Other than that you have to become a seagull and beg for the info from those who have done ladder tests.

For example, with Varget and the 175gr bullet, there is an accuracy node at max of 44.9/45.0gr. You'll find an accuracy node lower at 43.5/43.6gr which is commonly used by most shooters, and one lower at 42.2gr. Of course the H2O capacity of your brass matters (Winchester has more capacity than Federal for instance in 308).

[Lefty Savage]

Thanks for the info John. I've climbed that ladder before and couldn't get the heavier bullets to group. I happy with the performance of my Palmas, but still curious about thye 168 and 175's.
It also grouos the 110 V-Max really tight also and its is loaded to published max. or maybe .5gr under.

[Fjold]

See I had a similar question. My 10FLP .308 1:10 twist barrel won't group 168 or 175's very well. It does well to get MOA. But my 155 Palma hand loads shoot sub 1/2MOA. WHY???? The other thing (which I'm not complaining about) is it seems to like the load just under published max.


Some guns just like one particular bullet more than others.