Rifling twist for 20-250 55gr. Berger?

[John E Rupert]

Building a 20-250 and don't know what twist that I should use for the 55 gr. Berger's. Berger suggests a 8". Todd K. in his terrific twenty's book uses a lot of 9" twist barrels. Will the 8" twist also shoot the 40 grainer's OK? Like I said I'm getting confused on which to choose.

[rich44]

I have a 20-250 with a 9 twist also a 20br with a 9 they both shoot the 55gr Bergers very well I don't believe a 8 is necessary

[xswanted]

I'm also shooting a 9 twist in a 20-250.

I'm running the 55 at 3600 and the 50 at 3700, no problems with either.

I've shot the 40 Berger and the 35 Berger at 4100 and 4250 respectively and not had any blow ups.

I don't think a guy needs an 8 twist with the 20-250, 20BR or the 20x47

[Tim Anderson]

9, 9 1/2, or 10 with the 250 or 20x47 Lapua....

[Timbo]

I've shot the 40, 45, 50 & 55 in my 9 twist 20/250
Have had no problem with any of them
All grouped very well.
I don't think an 8 twist is required for these projectiles.
I haven't tried the 35 Bergers in it but have other 20's to use that projectile in.

[Alycidon]

There is a twist rate calculator on the Berger web site, from memory I think 55s come out at 1 in 9.

I use 1 in 9 for 39s/40s/45s and 50s, all shoot well.

A

[MrMajestic]

I split the difference and went with PacNor's 8 1/2! Shoots them great, 3640 fps at Sea level and 70+ Degrees.

[bobtails]

Originally Posted by rich44

I have a 20-250 with a 9 twist also a 20br with a 9 they both shoot the 55gr Bergers very well I don't believe a 8 is necessary

I too shoot a 20 BR with a 9 twist and it shoots the 55 bergers great. I also have a 9 twist on order for my 20-250.

[ccamp]

I shoot a 1in9 twist using the 57gr VLD Don Umssing Groups well but have not shot anything lighter than these.