20 BR with 55 Bergers

[dawe11]

20 BR with 55 Bergers
Getting ready for next trip to Montana for prairie dogs.
Am looking for advise on load data.
Savage single shot with Lilja 9 twist, Lapua brass etc.
Looking for best powder, velocity and accuracy.
JDale

 

[rcw3]

Just curious whether you have had the 20 cal. 55's stabilize in a 1:9" twist barrel. Berger's recommendation for that bullet is 1:8" twist. They probably have some margin built into the recommendation so maybe a true 1:8" is not needed (maybe 8.5" twist would be fine) but I wonder about a 1:9" with them.

Any info on that?

Robert

 

[pwdrbrn]

Check out Voldocs' post in Varminter section. 1K yd. pd's w/55 gr. and 20 BR.

 

[vargetman]

A 1in 9 twist is perfect for the 55 Berger,s. In a 1 and 8 twist at 3600 fps they will come apart. Try Reloader 17 at 31 grains to start with a CCI BR-4. Berger is conserative with there twist rates. I have a 20 BR on a Savage action and have never had any problems with bullet stability. It is devistating on ground hogs in Ohio.

John

 

[CZ550]

I run 33.5 grains of RL17. Not sure on velocity and I am sure some will dispute it but I am fairly certain I was around 3725. 1-9 Hart 26 in. Accuracy was unbelievable. It also shot 39 sbk with AA2230 around 4000 fps with super accuracy. 20br is one wicked prairie dog cartridge.

I might screw that barrel back on and shoot a 600br match with it for kicks and giggles.

 

[dawe11]

About a year ago I talked to Walt about using a nine twist. He was very interested how accurate was. I said that at about 3550 velocity at 1200 and
4100 ft the bullet was very accurate.
JDale

 

[vargetman]

CZ 550, I get 3675 with 33 grains of RE-17. So I think you are about spot on with the velocity you are getting. The 20 BR is a awesome round. I tryed several other powders and settled on RE17. It fills the case of which I like. I have a friend that shoots 40 grain V-Maxs at 4200 fps. He tryed to shoot the Sierra 39,s at that velocity and they came apart. he said the Sierras,s were good to about 4000 fps. I think you can shoot the 55 Bergers at 3250 in a 1 and 9 twist and still stabilize them.
John

 

[CZ550]

I had some 57 gr VLD unmissig bullets that would not stabilize in my 9 twist. I would love to see what it would do with a 8 twist and those 57's. Barrel life is a concern hope it holds up to 1000 or so, running those 55's with RL17 hard I will be surprised.

 

[JoeMcNeill]

What neck size is best for the 20BR? No turn or neck turn? What size bushing if neck turning the brass. Jump or jam?
I'm new to the 20BR and appreciate any and all help.
Thanks,

JDM