280 Ackley Load Development

[Jacko3006]

Hi I'm new to the 280 AI and I was wondering if someone has a good starting point point for me to develop a load . I have on hand H1000 and IMR 7977 powders and planning on shooting ELDX 162 or Berger 168 VLD . The rifle is a custom built with a benchmark 1:9 @ 26"

thanks for your help!

 

[Dmagna]

I shoot 160 accubonds. I like them better than the eldx. The bonded bullet is more appealing, I use reloder 26 for my heavier bullets. I think h4831sc is the ticket for consistency and temp stability in this cartridge.

 

[lancetkenyon]

H1000 is a great powder for the .280AI.
Not the fastest speeds, but super stable, accurate, and clean burning. I use it for my personal 160 TMK loads. I would start around 56.0gr. Work up slowly. I am quite a bit over that charge, and getting 2991fps. You can check Berger or Hodgdon's load data for the .280Rem and start with the max load. Also, they probably have .280AI load data available too.
Another great powder is RL23. I just finished a buddy's .280AI w. 160 TMKs and getting 3025fps with absolutely no pressure from a 26" 1:9" barrel with only 24 rounds down it. It is a Tikka, so has to fit in the mag, but in a longer mag, could seat the bullet out further if needed.
I use RL23 under a 175 Elite @ 2975fps for my main hunting load. It is at the top end, but safe in my rifle.

 

[jack0207]

26" barrel 1:9 (true twist 1:877")
162gn ELDX
61.5gns ADI 2213sc / H4831sc
Gets me 3026fps with low SD sitting on node 4.
Have pushed this with new brass to 62.4gns with slight ejector marks and with fired formed brass @62.4gns there isn't any marks at all and pressure should be under 65K PSI.

59gns ADI 2209 / H4350
Gets me 3020fps with similar sd.
Haven't played around with this load that much tbh but using GRT the z1/p1 are almost on top of each.

 

[nmbarta]

59.5 H-4831sc is close to max in one of mine. 162 eld-x @ 2920. 25" pipe. It ran the 168 vld at 2850.

Getting 2930 with the other with RL22, but will be changing that soon, I don't care for the powder. Run's good, but inconsistent pressure signs.

Keep in mind if your new to the 280ai that the straight wall on the case won't create as much bolt thrust. Meaning that it won't show pressure on the head of the case as soon as a case with more taper will. Ejector marks on ai cases are bad news imo.
Start low and pay attention to brass life, if your loosing primer pockets in a few firings.....your too hot.
Be mindful of what you read and don't have any expectations of your velocity. There's a lot a bad info on this cartridge on the net, and a LOT of people posting velocities that can't be had without being over pressure. No reference to this thread, but I'm sure your reading others in your research.

 

[Deputy819]

Hi I'm new to the 280 AI and I was wondering if someone has a good starting point point for me to develop a load . I have on hand H1000 and IMR 7977 powders and planning on shooting ELDX 162 or Berger 168 VLD . The rifle is a custom built with a benchmark 1:9 @ 26"

thanks for your help!

You're gonna love the .280AI for sure. Sounds like you've got a good build put together. Be sure and use quality components (brass, bullets, primers) and start development with the appropriate powder(s). I would probably get at least 100 rounds down the tube before I completely settled on a particular load. Use a chronograph if you can and document everything.
I put together a .280AI this year also. The load I settled on is on the mild side (2830-2840 fps), but it's accurate AND it repeats. This is the last 200 yard target I shot this year for verification before our deer rifle season opener.

 

[Jacko3006]

Thanks everyone!

 

[longbowelk]

59.5 H-4831sc is close to max in one of mine. 162 eld-x @ 2920. 25" pipe. It ran the 168 vld at 2850.

Getting 2930 with the other with RL22, but will be changing that soon, I don't care for the powder. Run's good, but inconsistent pressure signs.

Keep in mind if your new to the 280ai that the straight wall on the case won't create as much bolt thrust. Meaning that it won't show pressure on the head of the case as soon as a case with more taper will. Ejector marks on ai cases are bad news imo.
Start low and pay attention to brass life, if your loosing primer pockets in a few firings.....your too hot.
Be mindful of what you read and don't have any expectations of your velocity. There's a lot a bad info on this cartridge on the net, and a LOT of people posting velocities that can't be had without being over pressure. No reference to this thread, but I'm sure your reading others in your research.

 

[longbowelk]

Please explain ejector Mark's or possibly post pictures. I had a 280AI built using a Demulin action. Just using starting loads I was getting long scratches on my brass when ejecting the cases. I figured it was from the action. Very puzzling.

 

[Deputy819]

@ longbowelk

 

[Jacko3006]

And what are you using for primers ?

 

[Deputy819]

And what are you using for primers ?

Federal 210M