280 Ackley Improved

Below is the data I have. Keep in mind, I was basically looking for pressure / velocity so haven't done any accuracy testing yet. This was all shot with a 25" barrel.

Nosler brass, 168 H-VLD, 210M primers, RL-26, 60 degrees:
61 gr = 3,130 fps (pressure)
61.5 gr = 3,160 fps (heavy extractor, pressure)

these were the first 2 shots trying RL-26. Data was hard to come by so I started with what some guys were using for the new 175 gr. ELD-X bullet. this charge proved to be too much for my rifle, however. (I shot the 61.5 gr. load because I didn't believe my magnetospeed).

Nosler brass, 168 H-VLD, CCI 250 Primers, RL-26, 75 degrees:

58.5 - 2863 fps
59.0 - 29.2 fps
59.5 - 2931 fps
60.0 - 2927 fps
60.5 - 2997 fps

No signs of pressure or extractor marks

Nosler Brass, 175 Hornady ELD-X, CCI 250, RL-26, 75 degrees:

57.5 - 2791
58.0 - 2856
58.5 - 2879
59.0 - 2911
59.5 - 2926 *faint extractor mark
60.0 - 2983 *extractor mark

I retested some of the above with 210M primers and found velocity was better with them, but I cant find those notes.
 
I was using basically the same loads with cci 250 primers gave me better accuracy and a little more velosity
 
Below is the data I have. Keep in mind, I was basically looking for pressure / velocity so haven't done any accuracy testing yet. This was all shot with a 25" barrel.

Nosler brass, 168 H-VLD, 210M primers, RL-26, 60 degrees:
61 gr = 3,130 fps (pressure)
61.5 gr = 3,160 fps (heavy extractor, pressure)

these were the first 2 shots trying RL-26. Data was hard to come by so I started with what some guys were using for the new 175 gr. ELD-X bullet. this charge proved to be too much for my rifle, however. (I shot the 61.5 gr. load because I didn't believe my magnetospeed).

Nosler brass, 168 H-VLD, CCI 250 Primers, RL-26, 75 degrees:

58.5 - 2863 fps
59.0 - 29.2 fps
59.5 - 2931 fps
60.0 - 2927 fps
60.5 - 2997 fps

No signs of pressure or extractor marks

Nosler Brass, 175 Hornady ELD-X, CCI 250, RL-26, 75 degrees:

57.5 - 2791
58.0 - 2856
58.5 - 2879
59.0 - 2911
59.5 - 2926 *faint extractor mark
60.0 - 2983 *extractor mark

I retested some of the above with 210M primers and found velocity was better with them, but I cant find those notes.

That's a huge help. Thank you sir!
 
Wow so on the 280 Sherman or even the 300 Sherman do you just run a reamer on a existing 280 rem or 30-06? Do you need to fire form prior to making actual ammo? Thanks ahead of time.
 
Wow so on the 280 Sherman or even the 300 Sherman do you just run a reamer on a existing 280 rem or 30-06? Do you need to fire form prior to making actual ammo? Thanks ahead of time.

You can run a Sherman reamer behind a standard or an AI chamber to create the Sherman chamber.

Once done, you will now have to fire form your brass and use a specific reloading die.

It's a drastic difference once done. Here's some 22-250 before and after fire forming to an AI.
Fire forming.jpg
 
Hi All, this my first post on Long range hunting.com. I'm based in New Zealand. Picked up some RE23 for my 280 Ack. Would anyone have some starting loads that I could work up from. Trying 150gr BT's 160 sierra's and 162 ELD-X. Thanks Matt
 
You have to create a false shoulder by expanding the neck beyond the final diameter, then necking the front end of the neck to final diameter with correct headspace and fire forming.
 
Here's a before and after for my .25-06 AI brass.

On the left is a case that has been prepped and is ready to be fired in my .25-06 AI rifle for fire-forming. On the right is a fully-formed .25-06 AI case.

25-06 vs. 25-06 AI.jpeg
 
lancetkenyon said:
I started at 55.0gr RL23. Worked up to 59.0gr before I hit pressure. But 58.0 was the accuracy, and safe. I have shot it from 4° to 110° with no major discernable speed changes. About 22fps between the 106° temp extremes.

Where would be a good start point with RE23 and a 160gr in 280AI? Around 55gr as well?
Thanks
 
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