20 arc does anyone got one built

[Shotafterdark]

Already had the same bug up my ass about this 3 months ago ..

My reamers from PTG should be here in a week.

My cartridge . The 20 Fastback
Is a 22 arc Improved
Straight walled
Not a 40 but a 42 degree shoulder
In .204 "

I have the same in 223 in possession now
223 AI 42 degree shoulder in .204
Called it the Majestic 20


And then Dave has The 20 Slingshot
On the way as well .
204 in a 22 250 with a 42 degree shoulder.


I had Connor @ Hart barrels make me
3 MTU contour .204 blanks at 26" 1 in 7 "

I have them now .

Projects are being built on a KRG whiskey chassis and an MPA matrix pro

Ill keep you posted
First testing started..with the majestic 20
With low starting charge of 28 gr AA power pro mr showed 3578 fps with Berger 55s
And there's plenty of room to go.

Reamers all have zero freebore for the 55s.

 

[Shotafterdark]

My reasoning in utilizing a 42 degree shoulder is decreasing throat erosion

 

[Tommie]

No pissing match with me, just everthing researched said 33. Not my intent too.
Just curious if what I've researched is wrong or is there that much difference in case brands.

This is where I got my data

Nosler Load Data

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[Shotafterdark]

Left to right
22 arc 62 gr eld vt
223 AI 62 gr eld vt
20 Majestic 55 gr Berger

 

[Shotafterdark]

PTG finish and roughing reamers
20 majestic next to a 22 Creed reamer

 

[Shotafterdark]

Loads for fire forming

 

[Shotafterdark]

Once you start on a project like this, it's a good idea to get some die blanks from PTG
To ream for case work .

I also grabbed a set of 204 ruger
And reamed them out

I will be using my reamers
On my 22 arc and twenty 22 250 dies once my reamers get here.

 

[Shotafterdark]

I grabbed up a bunch of redding bushings ahead of time

Even have extras laying around

 

[Shotafterdark]

Hart Barrel blanks
204
1 in 7
26"

 

[Shotafterdark]

I really love the 20 majestic so far
I can get twenty nine grains
Of 2000 MR in the case and it only fills up to the shoulder.

I was getting close to twenty six hundred feet per second With twenty eight grains
With the 55 Bergers .

I can't wait to see what 2230 is going to provide.


I planned on shooting the fifty fives
In all of these as a dedicated projectile

With a 1 in 7 twist. I think I'm pretty much going to be limited to those. But I was kicking around grabbing up some 40 grain V maxes

With a zero freebore, I can pretty much use what I want

But overspinning those might b

e an issue

Looking forward to seeing how these things
Work on these big bodied coyotes out here in michigan

 

[Shotafterdark]

I had PTG send me some pilots
In stepped diameters for .224 so I can use these reamers on my twenty two caliber
Chambers.

Currently, my new 22 250 is waiting for this reamer.To show up so I can give it my new profile.
Improved straight wall and a 42 degree shoulder.

 

[Shotafterdark]

When I started this project, I grabbed up an aero solus action
As it was affordable and offered all three bolt heads that I needed for this project

Then Brad at urban riflemen
Told me about the Kauger company
He's a great guy and I listen to his advice
Let me tell you something this VPR action is saweet...

And they have bolt heads for sixty dollars
I can change this thing out
In any of my custom calibers in an hour

 

[Shotafterdark]

I am really anxious to get that 20 Fastback reamer here .
Nobody has improved the twenty two arc yet that I know of
Especially with regards to making it a twenty
So she's going to be a gorgeous little creature.

She should be able to get thirty eight grains stuffed in that little cartridge pretty easily

 

[Tommie]

I really love the 20 majestic so far

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