1-8 twist for 55 grain .20 cal Bergers?

[nakneker]

Those of you who are shooting the 55gr Bergers out of a 20 caliber cartridge, what twist rate is working for you? Berger recommends 1-7 or faster, that limits barrel manufacturers some what. Most offer a 1-8 but not all offer anything faster. Lilja and PacNor do 1-7s but…..

I want to use a Mueller for this build but 1-8 is his fastest twist.

This is for a 20GT build by the way.

Any input welcome.

 

[Tommie]

1-9” in a 20 BRX. No stability issues.

 

[Gabe22BR]

1-9… any

 

[L.Sherm]

1-9 all the way. I had a conversation with the late Stan Taylor and he told me he tested a 8, 8.5 and 9 and the 9 was the best.
This is all the proof I need with my 9, this is out of a gun that is nothing special, untouched 700, Boyds Thumbhole stock and 14oz trigger and a barrel I made.

 

[Evan]

Hart 9” twist in my 20 Vartarg stabilizes them at 5000ft elevation. 3050fps and they will almost shoot 1” at 600yards.

 

[RegionRat]

Any input welcome

What altitude do you shoot at, and what is the lowest altitude you would like to run?
How far will you want to shoot?

 

[L.Sherm]

I'm only at 2,000 elevation and I think Gabe has to be not far from sea level my money says you will be fine even at sea level with a 9

 

[L.Sherm]

Here's how I look at it numbers dont tell the tale just like the argument with E.S and S.D. numbers, targets snd real world experience is what matters

 

[rickiesrevenge]

I've run some short barreled 1in8 twist and they do great. Full length rifle and I'd do a 9t

 

[Gabe22BR]

Hart 9” twist in my 20 Vartarg stabilizes them at 5000ft elevation. 3050fps and they will almost shoot 1” at 600yards.

1-9 Kreiger 600yd BR
This is the 2nd time it’s proved it’s self-
20BRAI

 

[B23]

Krieger 8tw 20-250 for me w/Berger 55's

 

[nakneker]

What altitude do you shoot at, and what is the lowest altitude you would like to run?
How far will you want to shoot?

I live at 5800, we shoot between 4000 and 9500 for the most part. We can can get into some long shots where we call yotes. I could see taking shots over 500 on a regular basis, most shots will be inside of 300 though.

 

[nakneker]

Thanks guys! Berger recommends 1-7 so this is helpful and appreciated!

 

[nakneker]

1-9 all the way. I had a conversation with the late Stan Taylor and he told me he tested a 8, 8.5 and 9 and the 9 was the best.
This is all the proof I need with my 9, this is out of a gun that is nothing special, untouched 700, Boyds Thumbhole stock and 14oz trigger and a barrel I made.

Good info, was Stan testing the 55 Bergers? When you said you made the barrel does that mean you did the chambering and what not?

 

[Woollybugger]

Those of you who are shooting the 55gr Bergers out of a 20 caliber cartridge, what twist rate is working for you? Berger recommends 1-7 or faster, that limits barrel manufacturers some what. Most offer a 1-8 but not all offer anything faster. Lilja and PacNor do 1-7s but…..

I want to use a Mueller for this build but 1-8 is his fastest twist.

This is for a 20GT build by the way.

Any input welcome.

I have an 8T Mullerworks barrel in 20GT works well with the 55 bergers. not to rain on the 55 bergers parade, but my 22 GT shoots as well and as fast with the 53gr Vmax and the barrel will last longer.

 

[Gabe22BR]

I have an 8T Mullerworks barrel in 20GT works well with the 55 bergers. not to rain on the 55 bergers parade, but my 22 GT shoots as well and as fast with the 53gr Vmax and the barrel will last longer.

So you’re comparing the G1-.354BC 55gr to the G1 .218 Vmax..

 

[RegionRat]

I live at 5800, we shoot between 4000 and 9500 for the most part. We can can get into some long shots where we call yotes. I could see taking shots over 500 on a regular basis, most shots will be inside of 300 though.

0.204 Berger 55 at 3650 fps
DA, Twist, SG
4000, 1:7, 2.18
4000, 1:8, 1.76
4000, 1:9, 1.32

5000, 1:7, 2.25
5000, 1:8, 1.72
5000, 1:9, 1.36

6000, 1:7, 2.32
6000, 1:8. 1.78
6000, 1:9. 1.40

And the higher the Density Altitude, the easier things get.

I also shoot 1:9 down below 4000 feet.

I have even taken it down to sea level and it did fine at short range in low wind. However, push the distance or give it cross wind, and you will see the effects in reduced BC (more drop) and bigger groups.
At sea level my 1:9 has an SG of about 1.18 at 3650 fps.

At a DA of 2650 ft with the 1:9, my SG drops to 1.27 but I get away with it at distance and cross wind.
YMMV

 

[L.Sherm]

Good info, was Stan testing the 55 Bergers? When you said you made the barrel does that mean you did the chambering and what not?

Yes Stan was testing the 55's, I actually made the barrel its a 3G9 did not do the chambering.

 

[L.Sherm]

I live at 5800, we shoot between 4000 and 9500 for the most part. We can can get into some long shots where we call yotes. I could see taking shots over 500 on a regular basis, most shots will be inside of 300 though.

7315 on here has good info with the 55, twist and powders im pretty sure he's shot them to 1,000 in 9 shooting P.D and shot a 10 twist with 55's at 5,000 feet elevation shoot him a P.M.
Over the years on this subject I've heard of a couple people having trouble tearing 55's up with 8 after they get wear on the throat its exactly why I went 9 as you can see at 2000' at 665 I was having no stability issues.
I'm sure you've read on here that Dave Tooley has shot stuff down to 1.1 with no problem and actually prefers 1.2- 1.3 I'm in the same camp I believe the more you spin stuff unnecessarily it hurts the bullet its exactly why Stan told me he believed the 9 was better targets dont lie.
I actually have no idea why Berger recommends a 7 my guess is its because of B.C numbers but ill take accuracy every day.

 

[Woollybugger]

So you’re comparing the G1-.354BC 55gr to the G1 .218 Vmax..

53Vmax G1 BC is .290 I send them at 3850. Now compare to 400yds max. 1-1/2” drop 3” wind. I can hold either on a coyote. I would burn up a 20 cal barrel too quick on Pdogs so it won’t get compared on small pups.