Swift Scirocco II bullets - considered VLD's

[300winnie]

When the Swift Scirocco II first came out I was giddy with excitement as the original Scirocco shot wonderfully in my Browning A-Bolt .300 Win Mag. It was a sub-m.o.a. shooter with those bullets.

I took the II's out and tried them...and tried them...and tried them and could not get them to group worth a hoot. When I got a good group I couldn't duplicate it. I ended up canning the whole idea and moving to Nosler Accubonds.

For whatever reason I feel the urge to see if I can conquer the II's in my gun again. I have been doing a lot of reading and studying on where to go from here, and the best advice I can come up with is Eric Stecker's article on finding the sweet spot with VLD bullets.

I know that the Swift Scirocco II is designed with a secant ogive, thus qualifying it as a "VLD" type bullet. My question is this: Will the process he describes work with the Swift bullet, or are there other considerations I am missing?

Thanks

 

[benchracer]

I have found the Berger procedure to find optimum seating depth to work with both secant and tangent profile bullets. When working with hybrids I have found it to not be necessary, but that is another topic.

The Berger seating depth test will tell you if there is a seating depth that your rifle prefers for a given bullet. Every time I have tried it, a distinct preference emerged. From there, a powder charge run up using your preferred method will tell the tale of whether or not the bullet will shoot to the desired standard in your rifle.

My sense is that, if the VLD seating depth test followed by a powder charge runup doesn't yield a good load with a given bullet, nothing will.

 

[300winnie]

Benchracer,

Thank you for your input. Another question.

The load I had worked up with the original SS was max in my rifle with IMR 4831. I'm thinking I need to back down 1 to 2 grains to do the seating test. Is there any reason to do any more than that?

From what I can gather, the sweet spot will be consistent across various powders, so once found I just try the powders of my preference and increments that make safety sense.

Am I on the correct path here?

Thanks.

 

[benchracer]

I would advise doing your seating depth test with a powder charge at or near book starting load. Once you have your seating depth figured out, do a full powder charge runup. If your previous load was at or near max and your preferred seating depth is substantially deeper, you could end up causing a pressure spike. I think it would be wiser to back all the way down before you mess with seating depth.

As for trying other powders, my experience has been that the seating depth sweet spot stays constant for a given bullet, regardless of powder or primer used. Once your sweet spot is established, you only have to do the powder charge workup when you change powders.

 

[Mikecr]

I agree with benchracer

Oh, a VLD is not just a bullet having a secant ogive. It's a combination of attributes that fit a specific design by Bill Davis, and declared as a 'very low drag' bullet design.
But you could treat your Scirocco as a VLD.
As mentioned Berger's test is effective with pretty much any bullet, as it's really just a common sense approach to seating tests.

 

[Popapi]

DONE the seating depths with the SSII and ALL I could fair was a .597 4shot group out of my 47L........to say the least this group was NEVER consistent I really do feel SSII are a waste of time unless your satisfied with 3/4 -1 1/2" groups..

 

[Mikecr]

Was the .597 result of seating alone, or combined seating/powder adjustments?

 

[Rustystud]

Something to try with the Scirocco II bullets. They are made of a propriatary copper jacket compound. Much more ductile than the Scirocco I.

1. Clean your bore to bare metal. This means using both a carbon and copper solvent.

2. Fire 10 fouler rounds using Scirocco II bullets before ever trying for groups.

3. I found using H-4831sc with loads from 98-101% density loads worked best with Scirocco II bullets.

Nat Lambeth

 

[Popapi]

Was the .597 result of seating alone, or combined seating/powder adjustments?

Just seating........

 

[Mikecr]

Popapi, I don't don't know anything about SSII bullets, but to feel they are a waste of time without working up a load with them seems pretty weak.

 

[Joe King]

Popapi, I don't don't know anything about SSII bullets, but to feel they are a waste of time without working up a load with them seems pretty weak.

agreed if you can get 0.6- off seating alone is pretty good, since you have yet to find the powder charge it likes and it's preferred primer. It very well could have turned out to be a helluva load.

 

[Popapi]

Just seating........

Misunderstood sorry seating and powder adjustments in 3 different rifles built by 3 different smiths.......my bad gentleman.