264 win loads

Interesting stuff - good work.

The results are a bit puzzling. It seems like US869 is a bit slower than H870 as has been reported, as evidenced by lower MV's for the same powder weight, e.g. with a 140gr bullet, 75 grs of US869 produced about 3000 fps, while 75 grs of H870 produced about 3200 fps. What is strange is that you report signs of excessive pressure with the slower US869 at an MV lower than what seemed reasonable for the H870. If it was slower, you'd expect to be able to go to perhaps 80 grs (or a full case) and match if not exceed what you got with the H870.

How do their respective densities compare? Can you fit more or less US869 in the case than you can of H870? US869 is the most dense powder I've ever used (~98% of water).
 
On a new Win case, 83gr of US869 fills the case up to the base of the neck. I'd have to dig out the H870 to see where it would be at?

I too was shocked that 78gr gave me excessive pressure considering the speed. I was sure when I seen the speed I'd be able to go to 80gr easy. That was not the case though :(

Like I said, it seems to have a consistent MV even though it is slow speed, but why burn 18gr more @ 77gr US869 powder when I can get 3050 out of RL22 with 59gr? Also now that I am scrubbing the barrel US869 is also cleaner burning than H870.

You would think some other powder would yield similar results that H870 would?

64gr RL25 @ 3125 FPS is as close as I have come though :(
 
Not really amazing - it has the same case size, but a bigger bore, so it can burn more powder (or the same of a faster powder) at the same or lower pressures than the 264 Win Mag. The 338 Win Mag in turn can easily exceed 7mm Rem Mag velocities with the same bullet weights.

As for other powders similar to US869, they need to be very nearly as slow AND very nearly as dense to be comparable. Ignoring obsolete powders:

- VV 20N29: slower, but only 90% as dense. Couldn't get enough in the case;
- Magnum: a fair bit faster, and about as dense. Too fast to fill a case; and
- VV N170 or VV N570: a bit faster, but only 92% as dense. Worth a look.

Aside from H870, there doesn't seem to be anything quite like US869.
 
Andy said:
Not really amazing - it has the same case size, but a bigger bore, so it can burn more powder (or the same of a faster powder) at the same or lower pressures than the 264 Win Mag. The 338 Win Mag in turn can easily exceed 7mm Rem Mag velocities with the same bullet weights.
Click to expand...

I understand all that. What amazes me is that anyone, including my friend Wookie, bothers to mess around with the 264 when the others are available and so easy to load for.

3500 fps is a piece of cake with 130s, and I hunt with 150 Swift A-Frames at 3200 in my 270 Wby! :D

Ted
 
Why not? said:
I understand all that. What amazes me is that anyone, including my friend Wookie, bothers to mess around with the 264 when the others are available and so easy to load for.

3500 fps is a piece of cake with 130s, and I hunt with 150 Swift A-Frames at 3200 in my 270 Wby! :D

Ted
Click to expand...

Oh I just have to be difficult & different ;) Knowing what I know now, I'd have told Ted to make me a 7mm barrel instead of a 6.5mm :)

Oh well, still love the caliber :D
 
That is to bad US869 isn't working out. I bought 2-8lb kegs of it for my 264 a few months ago. I'm trying to locate the AA 8700 as i saw some at a shop a few months back.
 
Wookie, got any H1000, ramshot magnum, or magpro to try? Quickload shows they should work as well, but can't say for accuracy. retumbo is at the top of the list, as well as N570. I would also try different primers as you mentioned, CCI250 instead of 215's.
 
I get the bigger bore diameter , but with the 270wby capable of such speeds one would think the 264 would atleast be within 200fps of the wby
 
I did chronograph a 140gr load yesterday,was 140gr hornady max with a F215 primer and 72grs H50BMG,no pressure signs and was 3080fps.Very accurate, all 3 bullets were touching @ 100yds,fired 4 groups of 3 all were similar in accuracy. Will try working this load up alittle hotter. Anyone know how temperature sensitive H50BM is in the cold?
 
Grit, keep me posted on the 50BMG. I seen a pound & should have snagged it, but I though for sure US869 would be the cats A$$. I think I can get good accuracy out of the US869, but it is going to be in the 3100 FPS range in my rifle. It doesn't seem to want to take any more than that?
 
As I said earlier on this thread, I had no problems safely reaching 3200 fps with the 140 Partition using H5010. Now H50BMG is slightly slower burning than is H5010, so as long as you do not run out of room, I would think that H50BMG should get you where you want to go. Additionally, H50BMG is in current production, so it should not be difficult to lay some in. I would "guess" that the maximum load with the 140 will be somewhere around 75-78 grains. Regards, Eagleye.
 
A 264 is high performace, very long range deer/sheep/antelope cartridge.Just look at .600 BC 140gr at 3200 on your ballistics programs.However, the original design had a very short throat for the two diameter bullet Winchester used to maintain accuracy.Olin didn't really have a 264 powder,so they used a the two diameter bullet to keep pressures down. This has lead to spikes with ordinary bullets and some powders.The new powders,a normal throat and Berger VLDs put this cartridge at the top of this class.

Any long range rifle( and shooter) must be very accurate and fast.Not all rifles or shooters make the grade.
 
74gr H870 = Good in my books

Her is a good one for you. I was able to sneak away to do one last check before I head out for Antelope tomorrow AM (Early). I had some tight extractions @ 75g H870 & a 140gr Accubond. This is a load I tested ok not much more than a week ago & it rocked right around 3206 FPS. Yesterday the Chrony failed to read while I was getting hard extractions, so I don't have a clue what the speed was?

Fretting a stuck case on an animal last night I decided to drop down to 74gr H870 with a 140gr & sneak away to the range quickly to check all was in order. I also loaded my last 130gr Accubonds @ 75gr H870 as my back up.

Well either my Chrony is reading over a 100 FPS higher now, or I picked up 100 FPS from somwhere ?

Here were my speeds

140gr.

3304 FPS - 3371 FPS - 3324 FPS

130gr

3420 FPS - 3421 FPS (These were the 2 touching on the left group) - 3457 FPS

DSC_2644.jpg


I had no tight extractions. Now according to the measurement above the belt, case expansion was as follows:

New case .509

After firing .514

I check a few once fired cases with loads I know that were lower charges. They measured in the .513 -.5135 range.

So am I really shooting over 3300 FPS with a 140gr or is my chrony out to lunch? I think I'm starting to really like this rifle :)

_JAY5151.jpg
 
According to Sunray you should have blown up a long time ago :)

3200 makes sense.....at 3300 I would wonder is the muzzle blast affecting your Chrony.....try moving it away a little. In any case it will shoot flat and the Antelopes will not know the difference.
 
You must log in or register to reply here.
Back
Top Bottom