Berger 80.5 / 85.5 seating depth test

[garandman]

Todays work. I think all the parameters are on the targets:



Berger recommended starting the 80.5s right on the lands and the 85.5s 15 off the lands.

For the 1st 85.5 grp, I think I yanked the shot.

It was a fairly windy day and I didn't bother to pull out my wind flags so I'll probly re - run this test.

 

[1911nut]

A lot of your shots out of the group are low, you shouldering them?

What distance you shootin?

 

[garandman]

A lot of your shots out of the group are low, you shouldering them?

What distance you shootin?

100 yds.

Not sure why the low shots. The first group I think I yanked #5. The shot went off too quick... mighta shouldered it.

Loaded more tonite, will re-run soon.

 

[Shootin25]

A lot of your shots out of the group are low, you shouldering them?

What distance you shootin?

Can u guys explain “shouldered it”?

Does it literally mean contact with the shoulder?

 

[JFrank]

How light is your trigger pull?

 

[garandman]

Can u guys explain “shouldered it”?

Does it literally mean contact with the shoulder?

Shouldering the butt would tend to force the muzzle down, resulting in low shots.

What bugs me is all 5 of the 85.5 groups had that same low shot.

And the 80 5s had none.

The other factor is at this point I have a total of 75 rounds through a brand new barrel. So that may be causing the irregularity.

 

[Shootin25]

Man I have a lot to learn...

 

[1911nut]

I have interest in the Valkyrie in bolt guns. When the Valkyrie first came out I saw a picture of a Valkyrie case next to other varmint cartridge cases and I said to myself out loud “ that’s a Wasp” ..! So I got looking at the dimensions and sure enough, the Valkyrie is a rimless 219 Donaldson Wasp! Or it’s 98% dimensionally the same. Nice long neck, the magic 30* degree shoulder. Harvey Donaldson came up with a rimless Wasp based on the 30 Remington case but went back to the rimmed 219 Zipper case because it was stronger. He was shooting the Wasp to Swift+ velocities- he won a bet by deeper penetration into steel plates than a Swift. Pre LabRadar... circa 1940.

I’m considering building a bolt Valkyrie but with a 1:14 twist for a short range bench gun.

I learned a lot about the Wasp cartridge shootin this fat girl.



The 25 lb gun does this every time out @ 100 yds

 

[garandman]

How light is your trigger pull?

Below 8 oz. Which is as low as my RCBS gauge goes.

 

[garandman]

@1911nut ... thats a 52 gr bullet with a 1:14 ?

 

[1911nut]

So when I shoot a bench gun I want my shoulder about 1” from the butt -no contact. The experts say the rifle moves about a 1/2” back before the bullet leaves the barrel. I don’t want the gun to move farther cause it’s harder to get the dot back where it was last shot.

Off a bench, I do best with consistent shoulder pressure, some, not light not heavy however you can get that....

The demon of shouldering is * Anticipation * - anticipating the blast noise and recoil. You get it real bad and you’ll close your eyes and jerk your head to the right just as you push your shoulder forward to hit the butt pad...

 

[1911nut]

Below 8 oz. Which is as low as my RCBS gauge goes.

The Wasp has a double set trigger at ~ 4 oz

 

[1911nut]

@1911nut ... thats a 52 gr bullet with a 1:14 ?

Yup, 52g Sierra HPBT / 1:14” twist.

I got a 1:14”. 222 that outshoots the Wasp by a lot at 100.

I shoot mostly short range but have a few long range 22 centerfires.

 

[garandman]

So when I shoot a bench gun I want my shoulder about 1” from the butt -no contact. The experts say the rifle moves about a 1/2” back before the bullet leaves the barrel. I don’t want the gun to move farther cause it’s harder to get the dot back where it was last shot.

Off a bench, I do best with consistent shoulder pressure, some, not light not heavy however you can get that....

The demon of shouldering is * Anticipation * - anticipating the blast noise and recoil. You get it real bad and you’ll close your eyes and jerk your head to the right just as you push your shoulder forward to hit the butt pad...

I'll try that.

 

[swadiver]

i jam the 80.5's 10 thou. 1 in 7.7 twist Bartlein. powder is N140

 

[garandman]

@swadiver .... "jamming" 0.010... Does that make the bolt a "hard" close ?

Also I see a fair amount of N 140 used for the heavy bergers in 224. I guess I should try it?

 

[watercam]

I have had very good results with 80.5s jumped .040". Same with Sierra 90s and all of my non-VLD 155 gr. .308s. When in doubt, give it a try...

 

[garandman]

I have had very good results with 80.5s jumped .040". Same with Sierra 90s and all of my non-VLD 155 gr. .308s. When in doubt, give it a try...

Alotta ppl have. At least from what I've read, here.

For me, for the 85.5, getting 25 off opened the grps significantly.

For the 80.5, 15 off was a larger group than 10 off. (I'll be re-testing all that shortly.)

I wonder if I went to 0.040 off, if they'd close back down..... The other thing is, I wanna leave as much case capacity for powder, to maximize velocity.

 

[swadiver]

@swadiver .... "jamming" 0.010... Does that make the bolt a "hard" close ?

Also I see a fair amount of N 140 used for the heavy bergers in 224. I guess I should try it?

the bolt is not hard to close. only downside for jamming is that, in competition it is sometimes necessary to remove a chambered round to wait for your wind condition to return. don't want the round up in the hot chamber cooking away. sometimes when you pull a jammed round, the bullet will get stuck in the rifling and separate. then you have a mess. this does not happen often, but it is possible particularly if the neck tension is light.

my barrel has a long freebore. i would suggest working up to that load from about 10% off. Vhit lists 23 grs max for an 80 gr bullet. i have zero pressure signs at that load in MY barrel.

 

[shoot4fun]

On my initial tests with the 85.5 were done seated .010 off with CFE223, CCI400 and Lapua brass.
It was a small test lot varying from 23.2 to up to 23.7 grains.