280AI Loads

I haven't tried the 143 HH but that's pretty close to the same results I get with my 280 AI and Rldr 23. I get another 50 to 75 fps. Might be the 26" Hart barrel. But it always beats Rldr 26 in the accuracy dept like you found. I'll take accuracy over velocity so I roll with Rldr 23. Nice shooting! Not sure why your rifle didn't care for the 143 HH. Maybe a primer change? Or seating depth? They should shoot as well as the Accubonds.
 
I look forward to trying the hammers and RL 26 in my 280 AI. WOULD BE MORE THAN HAPPY WITH THE ACCURACY YOU GOT.
 
I am extremely happy with the accuracy I got from these loads and never expected it to shoot this well. I bought 2 of these Kimbers as rifles for upcoming sheep, grizzly, caribou and goat hunts and weigh in at around 6lbs 3 oz with scope. With their spaghetti thin barrels I was extremely happy with .6 inch groups especially with velocity around the 3100FPS; this was better than I ever had hoped for. The groups and velocity actually surpass my 9lb 7MM Rem Mag that I used to tote around in the mountains. These groups with RE23 really blew my mind in the accuracy department and I won't say I won't use these loads when it comes time for the actual hunt. I have some Rem 40x's that won't shoot this well. I will certainly do a little more testing when we get cooler weather and may also try the 150 LR Accubond/Re23 as they did fairly well with RE26 as well. The single shot with the 143 Hammer registered at 3201FPS on my Oehler but I had to almost hammer the bolt open; it was 90 degrees out so not exactly great load development weather. I didn't do much seating depth work with the Hammers; just set them deep enough as not to get marks from the lands on the olive; had to set them fairly deep for my rifles throat
 
I hit 3220-3240 with 140's in 3 280AIs and 24" barrels and 3070 in a 24" barrel with 162's all .5 m.o.a or less with RL23
I completely believe your numbers. I did hit 3201 with the 143 Hammer and probably would be betting numbers similar to yours with a 140 Accubond. If I were getting 3070 with my 160 I would certainly be using RE23. At 59gr I think I still had a little room to go until max as I was a full 100+ FPS behind your velocities. But accuracy as you can see was phenomenal
 
I completely believe your numbers. I did hit 3201 with the 143 Hammer and probably would be betting numbers similar to yours with a 140 Accubond. If I were getting 3070 with my 160 I would certainly be using RE23. At 59gr I think I still had a little room to go until max as I was a full 100+ FPS behind your velocities. But accuracy as you can see was phenomenal
With RL23 (63.9 gr) and the 143 Hammer, I'm getting 3260 fps and sub 0.5 moa accuracy.
With H4831 and the 150 LRAB, I'm hitting a little over 3100 fps with great accuracy.
I'm reworking a hot load with the 140 Absolute Hammer and HV100. I was over 3400 fps, but looks like it needs to be in the 3350-75 fps range. Even pushing it over 3400 fps, accuracy was outstanding.
This is in a 24", 1:8 twist, Criterion barrel (Remage) on a Rem 700 action.
 
I haven't tried the 143 HH but that's pretty close to the same results I get with my 280 AI and Rldr 23. I get another 50 to 75 fps. Might be the 26" Hart barrel. But it always beats Rldr 26 in the accuracy dept like you found. I'll take accuracy over velocity so I roll with Rldr 23. Nice shooting! Not sure why your rifle didn't care for the 143 HH. Maybe a primer change? Or seating depth? They should shoot as well as the Accubonds.
Always check for donuts forming in these improved chamberings. Especially if the throat is SAAMI depth. That will be the cause of a lot of vertical flyers if your brass is Nosler. Haven't tried my Peterson brass yet to see if it's gone forever but, sure wasted a lot of time correcting this issue.
 
With RL23 (63.9 gr) and the 143 Hammer, I'm getting 3260 fps and sub 0.5 moa accuracy.
With H4831 and the 150 LRAB, I'm hitting a little over 3100 fps with great accuracy.
I'm reworking a hot load with the 140 Absolute Hammer and HV100. I was over 3400 fps, but looks like it needs to be in the 3350-75 fps range. Even pushing it over 3400 fps, accuracy was outstanding.
This is in a 24", 1:8 twist, Criterion barrel (Remage) on a Rem 700 action.
I'll never reach these velocities with the 143 Hammer. At 62gr I am getting extreme pressure and only was able to get one velocity reading of 3201FPS
 
I thought I would share .. I had 280ai built and picked it up in April..25 inch Benchmark on a trued 700...Had 7977 and H4831 to play with shooting 175 Berger elites..Nothing was getting me excited until I tried some 8133..I figured it was going to be to slow.Not the case..2950 and shooting great...A good powder for the heavies..

 
With RL23 (63.9 gr) and the 143 Hammer, I'm getting 3260 fps and sub 0.5 moa accuracy.
With H4831 and the 150 LRAB, I'm hitting a little over 3100 fps with great accuracy.
I'm reworking a hot load with the 140 Absolute Hammer and HV100. I was over 3400 fps, but looks like it needs to be in the 3350-75 fps range. Even pushing it over 3400 fps, accuracy was outstanding.
This is in a 24", 1:8 twist, Criterion barrel (Remage) on a Rem 700 action.
Exactly what I wanted to hear about the 140 AH. I was hoping I could hit 3300 FPS. Building a 280AI to shoot this bullet. Now if my stock would show up!
 
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