The 264 WM grew up. Enter the 6.5mm - 300 Win Mag

Did a little more work...

So ,still looking at these loading numbers, I've found some more info. I've also looked at the 7mm Rem Mag numbers as they should be somewhat close to the 264....I know there not the same, but they are similar and there's a lot more 7mm date around
Lyman shows the 264 with H1000 max 63g, but at 43400 CUP
It shows the 7mm max as 72.7g and 60600 PSI

I can't remeber the relation between CUP to PSI but it seems that the 7mm is loaded hotter

Lee has the 264 max as 68g H1000 and 61037 PSI
The 7mm Mag max is 70g and 50600 CUP

Hodgen shows the 264 max as 58.5 at 61800PSI with H1000...gotta wonder about this one. That's a 10g differenct between Lee and Hodgen and getting the same PSI. But the Lyman and Lee numbers look closer together now that I compare pressures.....the Hodgen seems out to lunch. I wouldn't think that the 264WM could hold as much as the 7mm, as the hole is just smaller and ya gotta get all that hot gas out....but I would expect that the 264 would be a few percent behind the 7mm..but not 10g. Every gun is different but the 264 and the 7mm should share similar numbers. If a full house 7mm Rem Mag is around 69-71g of H1000, I would think a ballpark limit for the 264WM would be somewhere around 65-67g of the same. Of course maybe something magicaly changes in this case size when you go from 7 to 6.5 mm, but my common sence says it doesn't...they ya go, my .02$, I'm shooting groups tommorow with 62-67g.
 
thepitchedlink said:
So ,still looking at these loading numbers, I've found some more info. I've also looked at the 7mm Rem Mag numbers as they should be somewhat close to the 264....I know there not the same, but they are similar and there's a lot more 7mm date around
Lyman shows the 264 with H1000 max 63g, but at 43400 CUP
It shows the 7mm max as 72.7g and 60600 PSI

I can't remeber the relation between CUP to PSI but it seems that the 7mm is loaded hotter

Lee has the 264 max as 68g H1000 and 61037 PSI
The 7mm Mag max is 70g and 50600 CUP

Hodgen shows the 264 max as 58.5 at 61800PSI with H1000...gotta wonder about this one. That's a 10g differenct between Lee and Hodgen and getting the same PSI. But the Lyman and Lee numbers look closer together now that I compare pressures.....the Hodgen seems out to lunch. I wouldn't think that the 264WM could hold as much as the 7mm, as the hole is just smaller and ya gotta get all that hot gas out....but I would expect that the 264 would be a few percent behind the 7mm..but not 10g. Every gun is different but the 264 and the 7mm should share similar numbers. If a full house 7mm Rem Mag is around 69-71g of H1000, I would think a ballpark limit for the 264WM would be somewhere around 65-67g of the same. Of course maybe something magicaly changes in this case size when you go from 7 to 6.5 mm, but my common sence says it doesn't...they ya go, my .02$, I'm shooting groups tommorow with 62-67g.
Click to expand...

Your logic is sound, and I've used the same approach to develop loads before. The 7mm Rem Mag shares the same case as the 264 Win Mag, but has a slightly larger bore, so 7mm Rem Mag loads (of which there are many) would be too hot, and would serve as an upper limit (plus probably about 5%) for the 264 Win Mag. They would be about right for the larger 6.5mm-300 Win Mag.

There is no conversion factor between CUP and psi. Among the anomolies and oddities in their reloading data, Hodgdon uses both, often in the same table.
 
Curt, no your not misunderstanding, but you might not have seen the original numbers as I edited them out after looking at them closer. As you know the loading numbers for the 264 seem to be all over the place depending on what manual you look at. On my first load attempt with this round I started at where some manuals stop and by the time I was done had easily reached 3200+ fps. Andy kindly mentioned that I better have a closer look at what I was doing as I probably had exceeded the upper limit by several grains. So that's what I'm doing, cruching the numbers and trying to figure out where the hell they all came from and how there can be a difference of 10gs between 2 loading manuals in a round that only holds 68-70max. Looking closer at the numbers makes me think that they are not that different (except Hodgen:confused:) but have been recorded so differently that they seem unrelated. If you look close at the lyman and lee numbers that really are close to each other, although Lyman for some reason decided to record and publish info for a "high octane" magnum at 48000 CUP...who knows why...Lee chose to push it to 61000PSI, where it otta be!!! and as a result needed 68g to get there. Had Lyman kept going to 50-51000CUP, like with the published 7mm mag info, they probably would have needed 65 or 66g to get there, and be the same as Lee. Wow, that's more then my .02$, but it's kinda fun:D
 
6.5-300 Win Mag as it sits now.

Here are some updated photos of my 6.5mm-300 Win Mag. It now sports a 4.5x14x40mm 1" DPLX with CDS. The stock will be painted in a spiderweb paint finish in the new year. I may have the barreled action powder coated also.

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_JAY6606.jpg


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