My .264 WM is finally done and back from the gunsmith. I've been doing some load development for the rifle this week and thought some of you might find my experience interesting, as well as offering some input.

The barrel is a Walther chrome moly. 25". It's 25" because the first guy who was working on it (I "fired" him) cut the threads wrong. They had some slop in the fit between the action and barrel, so my new guy had to cut them off and re-thread the barrel correctly resulting in a 1" shorter barrel. Shucks! My gunsmith measured the bore diameter and reported that I might not get the velocity I was looking for before pressure was reached because it was "tight" for a .264 tube.

Well, I had some experience loading for this gun previously before the barrel had to be replaced. Stonecreek and the boys set me straight about powders and I was getting good velocity with the 140's and the slow stuff like US-869 and T-870 (3200fps). I was getting 3350 with W-780 and the 130's. I reported that I didn't even try the real slow stuff with the 130's and Stonecreek said that I would find the highest velocities even with the 130's with the slow powders.

I really wanted to shoot the new 140 gr Accubond. after about 30 rounds I gave up. Got around 3175 fps but could never get any accuracy even dropping the charge. I think that bullet is soooo long that the 9 twist barrel I have won't stabilize it. I topped out at 78 grains of US-869

I went out today and shot 3 Audette's tests with 3 different bullets with the US-869, the 129 SST, the 130 gr Accubond and the 140 gr Partition all at 300 yards.







The above is with the Accubond. Consecutive shots 9, 10, and 11 were at 3100 fps and measured 1.5"







The above is with the 129 gr SST. Shots 7, 8, 9 were at around the same velocity, a tad lower but measured .75"!!


I need to go back to the bench with some faster powders. W-780 was the star with the 129's in the last barrel. The T-870 is a touch faster than the US-869 so I'll try some of it too. But it looks like the 130's are gonna be accurate! Hopefully I'll get close to 3300 fps with one of these powders.

quote:

Stonecreek and the boys set me straight about powders

There are some seriously good reloaders here.

As to the groups, six of the ten are in good shape which suggests bad bullets to me.

I'd try a different bullet.

Hey rolltop

I think you might be missing the fact that all of these cartridges are loaded at different charge weights; 1 of each progressing up by .3 grains. You look for consequtive shots that group.

quote:

Originally posted by rcamuglia:
Hey rolltop

I think you might be missing the fact that all of these cartridges are loaded at different charge weights; 1 of each progressing up by .3 grains. You look for consequtive shots that group.

As a matter of fact, I didn't.

Humor me here and repeat the same string of ten shots and use the same bullet from a different lot.

I'll send you the bullets free to do this if you want. 6.5 Cal 129 gr SST

The bullets are fine. It's an Audette's ladder. You shoot one cartridge at each graduated charge weight at the same point of aim. Consequtive shots that group are close in charge weight shows the accuracy node. Why do you think the bullets are bad? 7 8 and 9 group at 3/4" at 300 yards!!!! That's 1/4 MOA!

I also like 3, 4 and 5 on the first target which may be your slower speed node. As far as I know, you're only supposed to be looking at elevation, not windage.

I've heard that too, but barrels do all kinds of weird movements when bullets are fired down them at 3K fps. I've wondered about that; I'm sure everyone during load testing has had No-wind groups at 100 yards even that deviated horizontally.

It occurs to me that many may not know what an Audette's ladder test is and how it's done.

http://mikeswillowlake.com/ladder%20test.htm

That link explains it well, just turn off the sound!

In the link, he states that the size of the clusters in the test don't necessarily mean that your actual load you settle on will group that tight. I bet it's a good indicator though.

I'm headed out now with the same bullet loaded with W-780 and T-870 and hope I get much higher velocity.

RC,
I am no expert, but have spent a lot of time reading about the CAM. I agree with you on where the nodes seem to be. The accubond looks good at the higher loads(9,10,11) and the SSTs look good with the 7,8,9. Just my 2 cents, but that is exactly where I would start. Again, just regurgitating what others have told me

Update

Good velocity with the T-870 and the W-780 up around 3200.

Bad "groups" . No clusters of consecutive shots.

Reached pressure quickly.

US-869 is the ticket.

So - PLEASE - post the load data for 264 w/ US 869 and W780. Hodgdon's web site is so far behind the power curve on the 264. They say there aren't enough folks loading for it to make it worth their while. I responded that it was Hodgdon that took my H870 away so they owed it to me to develop the data with the new powders. The Hodgdon rep just looked at me like I was from another planet. Oh well - I've had that "look" before.

I had an FN mauser put together with a Shilen barrel at 1/9" twist in the 264W and I couldn't get 140 grain bullets to shoot worth horse hocky, but it did a good job with 129-130 grainers. I no longer have this rifle as I wanted to shoot the heavier bullets in it and if I had it to do all over again I would never ever put a barrel on anything chambered in 6.5mm with less than an 8" twist. I have blabbed this over several forums but I am ignored and pooh poohed so..... whatever.

Absolutely right luckyducker. Mine is 9 twist and won't stabilize the 140 AB.

I went to 78 gr of US - 869 with the 140 and that was max for my gun. The barrel is tight. My last barrel I went to 80

A genuine question from a non-magnum shooter.

My 6.5X54MS rifles are both 1 in 7.5 inch twist (designed for 156 gr or 160 gr bullets). I think the military 6.5X55 was also 1 in 7.5. I wonder why people use 1 in 9 for the 264 win mag?

quote:

I wonder why people use 1 in 9 for the 264 win mag?

The .264 was never designed for more than 140 grain bullets and also the .264 shoots faster therefore increasing the RPMs automatically.

Stabilizing the bullet is a function of length of the bullet and RPMs.....not pitch! One gets that by one of two things (or a combination of each)
1. Increasing velocity
2. Increasing pitch. (twist rate)

Boy, when I look at those powder charges and velocities with those bullet weights, I really remember why I like a 270 so much!!!!