6.5 Creedmoor, Varget thoughts

[bikemutt]

After working with subsonic 300 BLK for a while, and some new (to me) powders like CFEBLK, I learned that some powders need to fully occupy the case volume, if not be compressed, in order to deliver accuracy.

In any event, my 300 BLK rifle was sent off for servicing so I started back on 6.5 Creedmoor, After measuring things with the Hornady COL gauge, I decided to add 42 grains of Varget to a fired case just see where the bullet would set COL-wise. Considering a used primer may be hollowed out versus a newly seated one, I chose 42 grains of powder as that's a tad more than I start with normally, lets say 0.2 grains heavy.

So now we have a fire formed case, with it's dead primer, and a new bullet sitting on 42 grains of Varget. Gently tapping the base of this arrangement to settle things down, then measuring tells me I'd need to seat the bullet such that the COL would be right at SAAMI minimum of 2.700". And that's with essentially no powder compression.

A Hornady 140 gr ELD-M bullet, if seated to SAAMI minimum COL of 2.700", would mean a bullet jump of 140/1000" in this rifle. If I seated it for 30/1000" bullet jump, I'd have a free case volume equal to the internal case diameter times 110/1000", whatever that works out to.

Is there a question here you ask? Yes.

In the esteemed expertise here at THR, is free (unfilled) case volume, with respect to Varget, more or less important than bullet jump?

Thank you.

 

[farmerboy78]

Varget may be a little fast for a 140... excellent for the 120's

 

[Captcurt]

I tried it with 120gr and 129gr and was not impressed. R17, H4350, IMR-4350, and 760 worked pretty well. Even with the 143gr ELD-X.

 

[VAReloader]

Varget didn't work for me either, H4350 is my choice.

 

[papajoe222]

To answer the OP's inquiry, "is free (unfilled) case volume, with respect to Varget, more or less important than bullet jump?" Way less important IMO. Although loading to almost case capacity may be preferable, finding the optimal distance to (or from, depending on how you want to phrase it) the lands for the particular bullet and firearm is paramount. Different powders will take up less/more of the case, but too much jump will affect your results much more negatively than a little more or less pressure from differences in case capacity.
Another vote for an alternative powder, and I'm a big fan of Varget. It depends on what kind of results you expect.

 

[bikemutt]

Guess I hadn't considered the powder angle; I'm not married to Varget.

H4350 noted, all suggestions welcomed.

 

[farmerboy78]

It was a hot load, but my savage lrp loved Norma reformed. 308 brass, 123gr amax, 43gr varget... shot 1/2" or better.

 

[Captcurt]

To answer the OP's inquiry, "is free (unfilled) case volume, with respect to Varget, more or less important than bullet jump?" Way less important IMO. Although loading to almost case capacity may be preferable, finding the optimal distance to (or from, depending on how you want to phrase it) the lands for the particular bullet and firearm is paramount. .

I agree, but I always wondered why Weatherby guns are long throated and still shoot well. I don't know if they are still chambered that way but they were several years ago.

 

[Kaldor]

I agree, but I always wondered why Weatherby guns are long throated and still shoot well. I don't know if they are still chambered that way but they were several years ago.

Any of the magnums are. Long leade to bleed pressure off right at firing to prevent pressure spikes.

 

[MtnCreek]

42 gr Varget + 140 gr bullet would likely cause damage to your rifle and possibly to yourself.

 

[bikemutt]

42 gr Varget + 140 gr bullet would likely cause damage to your rifle and possibly to yourself.

Good eye MtnCreek, I was looking at the 308 Win page in the book at the time I penned the question. However, having even less powder than 42 gr means even more empty space in the case. Sounds like maybe that's not an issue though.

 

[LoonWulf]

Ive played with varget some but never had great results. I have noticed little or no improvement with getting close case capacity with it.
Mostly ive found the slower powders, like 4350 or slower, to prefer to be near 100% or more. My best Retumbo loads are all compressed. My 4895 loads are not.