I am new to this forum... I am wondering if anyone has worked with RL-25 or Retumbo powders while developing loads for the 264 win. mag.. I plan on using the 129gr. or 140 SST bullets. Have not decided yet? I just need somewhere to start. Can anyone help?

For 140's:
RL-25 From 60.5 grains to 64.0 grains
Winchester WLR Primer

I have used neither, but from years of experience with the .264, I believe that the burning rate of either powder is perhaps suitable for 129 grain bullets, but is too fast for optimum performance with 140's

Forgive my ignorance, but, I thought these two powders were on the burn rate chart as slow burning? I am not understanding your reference to "too fast" for optimum performance with the 140's?

quote:

Originally posted by ricciardelli:
For 140's:
RL-25 From 60.5 grains to 64.0 grains
Winchester WLR Primer

Thank You for the info....

quote:

Originally posted by Trenton:
I am new to this forum... I am wondering if anyone has worked with RL-25 or Retumbo powders while developing loads for the 264 win. mag.. I plan on using the 129gr. or 140 SST bullets. Have not decided yet? I just need somewhere to start. Can anyone help?

129 Hornady sp# 2620
RL-25 My rifle maxed out at 67 grains
GM-215 primers
sd=10
avg 3296 fps 24" tube
3 shot groups at 100 yards was .6

quote:

Originally posted by Stonecreek:
I have used neither, but from years of experience with the .264, I believe that the burning rate of either powder is perhaps suitable for 129 grain bullets, but is too fast for optimum performance with 140's

Yup...they sure are fast...they are faster than
213 AA-8700
214 24N-41
215 20N-29
216 24N-21
217 H-50BMG
218 AR-2218
219 H-5010
220 W-870
but not by much...

[/QUOTE]
Yup...they sure are fast...they are faster than
213 AA-8700
214 24N-41
215 20N-29
216 24N-21
217 H-50BMG
218 AR-2218
219 H-5010
220 W-870
but not by much...
[/QUOTE]

As an example of just how relatively fast those powders are, you indicate no more than 64 grains for RL-25 with a 140 grain bullet. Speer Manual Number 9 indicated up to 75 grains of H-870 (my gun topped out at 72) and I use approximately 80 grains of WC-872. So, with a ratio of 64/72/80, I'd say that RL-25 is quite a bit faster than either of the other powders. In fact, RL-25 is only marginally slower than original surplus 4831, and perhaps no slower than IMR 7828. RL-25, 4831, and 7828 are all too fast for optimum velocities in a cartridge like the .264 Winchester with such a low expansion ratio and high SD projectiles.

After working up handloads for a 264 WM using 140 and 120 grain bullets, what I really wanted was a longer barrel than the stock 24". I think a 26" (or longer) tube would really help on a 264 WM. But, if a longer barrel is out of the question, then your left with slower powders.

Woody

Assuming you are filling the case to 95% capacity with the following powders and capping-off with a 140 grain bullet:

Powder        Grains      Pressure     Velocity
H-870         69.5        44K          2809
IMR-4831      66.4        80K          3214
IMR-7828      65.8        64K          3132
RL-25         66.2        59K          3037

As for the reference you give from the old Speer manual (102.6% capacity):

H-870         75.0        57K          3074

And my "max" load of 64.0 grains (91.8% capacity):

RL-25         64.0        53K          2946

And my personal favorite load is (99.8% capacity):

H-870         73.0        52K          2979

I don't believe that the additional 5K PSI to 28K PSI is worth the few extra FPS obtained.

Neither worked for me,in my 264.If using RL-25 allow a complete cool down between shots.I found with each shot in a group the velocity increased markedly.

For me Ramshot Magnum and AA's Magpro worked well.

quote:

Originally posted by downwindtracker2:
...
For me Ramshot Magnum and AA's Magpro worked well.

What bullet weights did you use with ramshot mag.

I'm going to work up a load with nosler 125gr partitions and would like to use something a little less temp sensitive than the alliant powder.

I have settled on H-1000, 70 grs with a 140 gr NPT chornos 3185 in a 24 inch barrel and if I do my part 3 shots will go into the same hole. But I have heard people complain about erradict pressures with H-1000 in the 264. So far I have not experienced problems.

One other note is I noticed when working with this gun. I love 129 gr Interlocks, but I can drive the 140 Partitions about 70 fps faster. All I can figure is the Interlocks must have more bearing surface or harder jackets.

Saludos...Frank

I have the press release about the 264 from Winchester,a lot of it is in Pet Loads. Winchester loved the European 139gr bullet,so the 264 was designed for a 140gr.It's the best of the trade offs,wind drift ,retained velocity,drop,and down range energy.I used 140gr SSTs with their hgh BC.

My powder results mirror John Barness's in Handloader.

And I am one of those who had problems with H-1000 in the 264's first barrel.It is not very lineral.It spikes.On a less overbore cartridge it would not be such an issue.