Is there an Ideal "powder" capacity for the 6.5MM bore?

That's sort of an interesting question, because of the variety and range of "successful" cartridges in 6.5mm. From 6.5 Grendel to 264 WM. Of course what makes it additionally interesting is that each cartridge has its ideal powder(s) which takes into account the case capacity.

For example, H335 would not be a good choice for the 264 WM while H4831 or IMR 7828 would not be good in the Grendel

So, It's my opinion that there is no one ideal case capacity simply because it's only one factor in the formula.

KB

And target intentions will dictate ideal case capacity as well. Paper or meat and expected range to be involved.
30-35gn of powder will get most 120-130 gn bullets (of suitable construction type for the intended target) away at suficient velocity to take care of business at least out to intermediate range. At least that is my expectation in building my 6.5 Gm that has a water capacity of 37.5 gn and will be expected to get a 123gn bullet away at 2700fps for an intended 500yd capability on meat. Paper will extend that distance somewhat.

If you question is "where do you get the mostest for the leastest with a 6.5mm bullet I'd imagine it's somewhere around the 6.5 sweed to .260 Rem catagory.

Those old sweeds know what they were doing 120 years ago.

I think the 6.5 MS or 6.5 Carcano is about the ideal especially with a long barrel.

What barrel length? That is also a factor.

Something in the 260 - 6.5x55 range would seem about right for bullets under 130grs, and/or hunting purposes. For the long 140's and long range targets, the x284 case seems to be where it's at.

How about the 6.5 Creedmoor?

quote:

Originally posted by Claret_Dabbler:
Something in the 260 - 6.5x55 range would seem about right for bullets under 130grs, and/or hunting purposes. For the long 140's and long range targets, the x284 case seems to be where it's at.

BINGO! I think that you are on to it Claret_Dabbler. I also think that the Ideal powder capacity HAS to vary with the specific powder used & bullet weight & maybe barrel length as TheBack40 has suggested.

quote:

Originally posted by SR4759:
I think the 6.5 MS or 6.5 Carcano is about the ideal especially with a long barrel.

I think there is a lot of truth here.Having used the Carcano for a number of years I found it to be a suitable deer cartridge.
With a deep throat as it has the heavier bullets can be seated out and not infringe on the powder room. In a modern day rifle and loaded with heavy bullets, at pressures a little greater than 55,000 psi. The Carcano's performance does not fall far short of the .260.
A rough calculation shows that if the .260 moves a 160 gr. bullet at 2500 fps the Carcano will drive the same bullet at 2400 fps. barrel length being equal. That ain't too shabby. roger

quote:

Originally posted by D Humbarger:

quote:

Originally posted by Claret_Dabbler:
Something in the 260 - 6.5x55 range would seem about right for bullets under 130grs, and/or hunting purposes. For the long 140's and long range targets, the x284 case seems to be where it's at.

BINGO! I think that you are on to it Claret_Dabbler. I also think that the Ideal powder capacity HAS to vary with the specific powder used & bullet weight & maybe barrel length as TheBack40 has suggested.

I pretty much agree with that. There was a time when the 6.5-06 was considered grossly "overbore". But that was before slower burning powders pretty much legitimized a lot of such chamberings.

It depends on the bullet you want to launch and how fast you want to launch it.

I love what my 260 does with Hornady 129 grainers and such, but for the 140's and up I personaly would prefer a bit more capacity. YMMV.