Just how tough is the .204 Berger 55 Gr ? Ill tell ya

[Shotafterdark]

OK guys DO NOT attempt this......ever !
I am testing loads with my newly built rifle ...
It's my Fastback 204

A 22 ARC Cartridge necked down to a 20 cal
42 degree shoulder and straight wall'd

Barrel is a NEW Hart 27" 1in7" Twist .204
on an Aero Solus Action and Solus Chassis

I had an Aero Lahar 30L can on it with a Spleen splitter dual
port break .

I fire formed a starline case first with 30 gr Power Pro 2000 MR
Then proceeded to fill it to the top of the shoulder with 35Gr PP 2000 MR
and seated the long 55 Gr Berger Varmint .@ 2.164"

Touching the Lands already established to be 2.230" with the 55

Put on my safety glasses and blast shield ....and proceeded to fire it .

Are you ready for this ? The lil Athlon Chrony gave me 3970.8 FPS
That's 408342 RPM and it stayed together ...

Paper at 20 yards was a clean lil hole ...


Wow ! I'm impressed I wasn't fragged in the process
blew the primer and she was tight to extract ..


Ill be going back to 32 grains max and leave well enough alone...
Ill look for 3700 fps and be happy as it get's .


I'm thinking I won't be in a rush to chamber my other blanks with that 20 250 AI
soon .. This will keep me occupied .

 

[Shotafterdark]

Hicker Billys shoot from the bedroom when temps are in single digits

 

[Shotafterdark]

Ive grabbed a nice stash of 40 Gr Vmax in .204 and will see what they group like
in this barrel ..

Ill probably use some 2230 and Superformance and RL15 to see what may work
I am hoping the 7 twist will allow for a load that doesn't over stabilize and get
erratic

we shall see...

I talked to the people at Sierra and they told me they have zero plans for any 20 cal
bullets that we may consider heavy .

 

[Shotafterdark]

 

[L.Sherm]

Ill look for 3700 fps and be happy as it get's .

You might wanna think of staying around the 3500fps mark, 3700 is BRA territory.

 

[Shotafterdark]

You might wanna think of staying around the 3500fps mark, 3700 is BRA territory.

I hit 3550 with the 20 223 AI and was just starting that was under 30 gr
we shall see ...I will tweak what I can out of it ...

My main goal is uber efficiency ..speed with less powder ,,,
Powder is expensive,,,

 

[7315br]

Just my opinion...but you might want to back off a bit as Sherm said. My .20/250 was just a necked down version of the .22/250 to .20 cal with no other changes. 10-twist Kreiger bbl (trying to keep the rpm down). It shot great...but I had numerous issues with it at the higher velocities. I only shot the 55 gr Bergers. I got the fps up to just over 4,000 fps...but exaction problems developed. Finally ended up with the 55 gr Berger at 3830 fps (shot well). The other "main" issue was low barrel life. 416 rds and the throat was gone.

Best of luck on your development.

 

[Shotafterdark]

Just my opinion...but you might want to back off a bit as Sherm said. My .20/250 was just a necked down version of the .22/250 to .20 cal with no other changes. 10-twist Kreiger bbl (trying to keep the rpm down). It shot great...but I had numerous issues with it at the higher velocities. I only shot the 55 gr Bergers. I got the fps up to just over 4,000 fps...but exaction problems developed. Finally ended up with the 55 gr Berger at 3830 fps (shot well). The other "main" issue was low barrel life. 416 rds and the throat was gone.

Best of luck on your development.

You mean back off alot of a bit ! like 3 grains ....yes sir duly noted

 

[Ackman]

To each his own, but......something like that why would you want to mess with a 7twist barrel?

 

[L.Sherm]

I wouldnt be surprised that 30gr of 2000 wasn't 100,000 PSI im sure somebody with quickload could calculate it.

 

[Shotafterdark]

To each his own, but......something like that why would you want to mess with a 7twist barrel?

Because I can play with heavy 20 cal bullets and you guys with your slow twist can't .

I never liked to follow but rather leave the crowd and blaze my own trails.
I'll call Don and get some 60's and we will see who is connecting at 800 yards

Hell I'll bet I can do that with these 55's

 

[Shotafterdark]

I wouldnt be surprised that 30gr of 2000 wasn't 100,000 PSI im sure somebody with quickload could calculate it.

Just wrapped up another shooting session with various powders and came to my conclusion
with the 55 Gr Berger

PP2000 MR is tops ,,,,I stopped at 33 grains and hit 3547 fps with zero signs of pressure
Tight primer pocket and NOT flat whatsoever, bolt opened with ease, Quiet!!

RL15 was closest and I'll still play further with it ...28 grains took me to the bottom of the neck
and gave 3511 fps ....no signs of pressure .

I'm sure I can go 30 grains with RL15
Win 760 @ 31.7 Gr gave me 3477 fps was loud
Superformance was NOT fast 33 grains only gave me 3346 fps and was quiet
I fired a few rounds (4) with superformance and climbed slowly and cautiosly
as it seems to hold alot more powder in the case , compared to the others.
Velocity wasn't there like I expected.

That was it for today ,,,,I'll pursue RL15 a bit more ..

And now the fun part after firing 10 rounds of various powders at various velocities my group was insanely tight.
I'm shooting off of a tripod sitting behind it not even in the bags.

 

[Shotafterdark]

I am not going to expect to see 3700 fps , but 3550 is cool with repeatability
and it's quiet! The question is , will this 55 Gr perform on Coyotes like I need at that
velocity ?? we shall see.

RL15 gave me 3511 with 28 grains I know I can stuff 30 grains in it
so tomorrow maybe Ill see if I can break 3650 fps without incident .


I have a wilson barrel from Brad 26" on my Tikka ,,,I didn't bother chasing the chamber
as it only changes 2 degrees on the shoulder from his 40 degree. in the 20 223 (sploder)
I saw 3556 fps in that with the 55 Berger and had 28 gr 2000 MR ....??? Hmmmm

That looks like it may be the true performer with less powder.

 

[rickiesrevenge]

Report back when you have a couple hundred rounds on the throat. You can get away with a lot when the throat is fresh. Once it gets a little rough itll start damaging jackets enough for them to puff

 

[Shotafterdark]

Report back when you have a couple hundred rounds on the throat. You can get away with a lot when the throat is fresh. Once it gets a little rough itll start damaging jackets enough for them to puff

Im a yote hunter ....wanna know how long itll take me to burn 2 to 300 rounds in an uber accurate bolt gun

Thats a whole lotta hours in the field , and I mean a LOT

 

[rickiesrevenge]

And? Whats your point? I bet itll be way sooner than you think before your puffing bullets. But what do I know. Only been shooting big 20s and 55s for a decade or so.

 

[Stormbringer]

Because I can play with heavy 20 cal bullets and you guys with your slow twist can't .

I never liked to follow but rather leave the crowd and blaze my own trails.
I'll call Don and get some 60's and we will see who is connecting at 800 yards

Hell I'll bet I can do that with these 55's

Hell, I've done it with 32, 35, 39 and 40's. Not much of a challenge with a 20 BR or 204 Ruger.

 

[Shotafterdark]

And? Whats your point? I bet itll be way sooner than you think before your puffing bullets. But what do I know. Only been shooting big 20s and 55s for a decade or so.

Lol send me your address
And I'll mail you big fresh cookie

 

[Shotafterdark]

And? Whats your point? I bet itll be way sooner than you think before your puffing bullets. But what do I know. Only been shooting big 20s and 55s for a decade or so.

Why do azzholes like you always show up to trash a thread ?
You're like flies to chit ...

 

[JSH]

Why do azzholes like you always show up to trash a thread ?
You're like flies to chit ...

Uh, you might want to go do a thread search on these gentlemen. They have experience that may well save you some grief.
All of them helped or commented off an on when I did my 20BR build. I will say it went smooth as butter and was one of the easiest I have ever done. Load work went like clock work and was a pure pleasure. I got to my speed window with excellent accuracy with the 55’s.

I am a speed freak as well, but I won’t give up accuracy. And if I have to give up 1-300FPS to gain a fair bit of barrel life I will.