20 cal build for 55 Bergers

[Tragiq]

I'm building a 20 cal to use the 55 Bergers. This rifle will be dedicated to target shooting only. I've found a good amount of info on the 20 BR using the 55 gr, which makes sense given the 20 BR's capacity. Most people seem to be getting around 3,600 fps. However, it's too much of a barrel burner for me. Has anyone shot 55s through a 20 ARC? I already have a 6mm ARC so it would be great to use some of that brass and just neck it down. Or 20 PPC? I'm curious what the barrel life would be for those cartridges.

Also, I'm going to assume that nobody here has ever run 55s through the tiny VarTarg but I'll ask anyways - does anyone have an estimate of the muzzle velocity of 55s through the VT? That long barrel life is tempting. At 5K elevation where I shoot, 55s running as low as 2750 fps have the same windage as 40 gr v max running at 3,450 fps.

[rickiesrevenge]

I read about a guy shooting the 55s in a 20vt. He was getting about 3200fps if I remember correctly. I remember that because thats what my 17" 20BR gets with them. Barrels are consumable and performance comes at a cost.

[Grey_Wolf]

I built my first 20 Extreme to run the 55's. I get about 3200 out of a 24", 8 twist Jury barrel using 21.1 grains of IMR 8208.
You can get Berger 55's?

[17VLD]

Berger makes an annual run of these and Grafs carries these,they are in stock now.I tried to post a link,but ever since I dropped this IPad it doesn’t like me anymore
Matt

[gundog]

The round that you are describing, 20 ARC, was developed by Todd Kindler, to shoot the 55's.

It's called the 20 Titan.

The Titan is based on the 6.5 Grendel, which is the parent case for the ARC.

The round is described in Todd's "Terrific Twenties" book.

I would think that there will be some correlation between the two as far as load and performance.

I've pushed the round to 3850 fps, but the case life is terrible at that speed. 3600 to 3700 fps is very attainable with good case life. Accuracy is incredible.

After a few thousand rounds the throat in one of the guns is starting to show some wear.

[Mntngoat]

id go PPC or Begg. Its easier on barrels than the BR. I have a Kebley Atlas in .20 Beggs's But i have not shot 55's out of it https://www.accurateshooter.com/cart...caliber/#20PPC

ML

[Bill K]

Go with either the 20 Titan or a 20 VTT, like Kindle has in his Twenties book, both easy to work with and would fill your needs very well.
VTT is very easy on recoil and the Titan is not much more, so you would really enjoy your target shooting and keeping the barrels cool, will allow you many round down the tube, before you would need to re-barrel. Run them in a bore with around a 1-8 or 1-9 twist.

[Tragiq]

Originally Posted by gundog

The round that you are describing, 20 ARC, was developed by Todd Kindler, to shoot the 55's.

It's called the 20 Titan.

The Titan is based on the 6.5 Grendel, which is the parent case for the ARC.

The round is described in Todd's "Terrific Twenties" book.

I would think that there will be some correlation between the two as far as load and performance.

I've pushed the round to 3850 fps, but the case life is terrible at that speed. 3600 to 3700 fps is very attainable with good case life. Accuracy is incredible.

After a few thousand rounds the throat in one of the guns is starting to show some wear.

Yes, I would agree that the performance is very similar - maybe 25 to 50 fps less on the ARC. I'm very happy to hear that the barrel made it a few thousand rounds before the barrel was showing wear. I was concerned that I would be limited to something ridiculous like 700-1000 rounds before the barrel had to be tossed

[JSH]

I built a 20BR, more case capacity. I see little use of going with 220 Russian parent case.

I see and read a lot of folks saying these smaller cases will equal a larger case with less powders. Yes they can but with added pressures and faster burning powders. There is no way around pressures, it is science and no way around it.
Yet I still see folks mention XYZ cartridge getting warp speed with “no pressure signs”, while other larger capacity cases achieve it fairly easily.

[458win]

Originally Posted by JSH

I built a 20BR, more case capacity. I see little use of going with 220 Russian parent case.

I see and read a lot of folks saying these smaller cases will equal a larger case with less powders. Yes they can but with added pressures and faster burning powders. There is no way around pressures, it is science and no way around it.
Yet I still see folks mention XYZ cartridge getting warp speed with “no pressure signs”, while other larger capacity cases achieve it fairly easily.

X2 if your going to run 55s use a case with enough capacity to get the velocity up there.