BERGER 20 Cal 55gr Bullets

[Dean Slater]

Tell more about the 20 dasher

I didn't continue with it after the trouble with the 7.5 twist barrel failure. I was disgusted with the whole thing and parted the gun out and moved on. I am however in the process of putting together a 20 BRA with the guidance of a fellow member with experience with it. Have not got it all together yet.

 

[Evan]

I mostly shoot at 5000ft and above, but my Vartarg gets them going 3100fps in a 9 twist Hart barrel and has regularly flirted with 1 inch groups at 600yards, so I think it’s stable! It is a phenomenal bullet.

My 20 Vartarg custom

Hi all, I'm not sure where to put this, but I figured the main board was ok. I've had this project in the works since August. Here's the spec's: Borden Rimrock BR, Right Bolt, Left Port, Right Eject Hart 26" 1in9 twist chambered in 20 Vartarg Picatinny Rail Jewell trigger All put together by...

forum.accurateshooter.com

 

[Laurie]

I mostly shoot at 5000ft and above, but my Vartarg gets them going 3100fps in a 9 twist Hart barrel

That 5,000ft and above altitude makes a big difference though compared to someone shooting at low elevations. The 55gn 204 is listed in Berger's Stability calculator and you can play the options on it.

Depending on ambient temperature, your situation just achieves 1.4Sg which was the standard for optimum stability for years until it was found that 1.5 was needed to achieve the full BC value. However at the 'standard ballistics' 59-deg F and 500ft ASL elevation, Sg is only 1.14. Drop to 32-deg freezing level and it's below 1.1 - definitely unstable.

It looks like the bullet is too fragile to take the rotational speeds / twist rates needed to make Berger's recommended 1.5 factor.

 

[flatlander]

I shoot the 55s out of a couple of Bartlein 1-9tw bbls - 23" one on a Howa Mini, the other a 25" on a M700 that I had LRI do their Tier 1 truing job on - both chambered for 20 Tactical. With H4895, I call 3200fps a max load with the 55s in either rifle. Kind of amazing to shoot groups on steel at 600 with these little pills and see decent groups form at that distance. Have been waiting on an opportunity to try these 55s on a coyote - hope they expand reliably for a humane kill...

 

[Evan]

I shoot the 55s out of a couple of Bartlein 1-9tw bbls - 23" one on a Howa Mini, the other a 25" on a M700 that I had LRI do their Tier 1 truing job on - both chambered for 20 Tactical. With H4895, I call 3200fps a max load with the 55s in either rifle. Kind of amazing to shoot groups on steel at 600 with these little pills and see decent groups form at that distance. Have been waiting on an opportunity to try these 55s on a coyote - hope they expand reliably for a humane kill...

They are surprisingly consistent aren’t they? They always feel controllable even though the wind pushes them around quite a bit at 600.

 

[shoots100]

I shoot the 55s out of a couple of Bartlein 1-9tw bbls - 23" one on a Howa Mini, the other a 25" on a M700 that I had LRI do their Tier 1 truing job on - both chambered for 20 Tactical. With H4895, I call 3200fps a max load with the 55s in either rifle. Kind of amazing to shoot groups on steel at 600 with these little pills and see decent groups form at that distance. Have been waiting on an opportunity to try these 55s on a coyote - hope they expand reliably for a humane kill...

In my 20-250 the 55's drop coyote like a hot potato.

 

[L.Sherm]

Going off off of numbers doesn't always work, the 20 cal 55's is a prime example of listening to experience trumps.