Powder and primer suggestions for 280ai

codym

WKR
Joined
Jan 30, 2018
Messages
483
Location
Las Cruces
Honestly with the 140-160 class bullet get h4831sc and if you don’t find a super accurate super temp stable load I would be surprised. I could push the 162 eldms at 3000 out of a 26 barrel and the 168 Berger’s at 2930 pretty easily. I don’t really like the 140’s out of the 280ai, I think the 160-175’s are optimum.
 
Joined
Jul 18, 2019
Messages
22
Location
TEXAS
I spent a lot of time playing with loads for my Cooper Backcountry in 280ai.

160 gr Nosler Accubond
Got great speeds with IMR7828.
Settled on H4831 - very temp stable, and consistent velocity (ES/SD). With loads developed early in the year (cooler temps), I was shooting yesterday with 100F ambient temperature with no higher pressures and same POI. Bullets running about 2850-2900fps. Different primers effected the loads, too. Ended up with a FED 210M.
 
Joined
Jun 15, 2017
Messages
414
Location
Wyoming
Definitely late to the party here, but I have had great luck with RL17 and RL19 for 140 (Barnes TTSX) and 160 (Accubonds) through my 280 ai. After farting around with several load combos I just settled on the 140 ttsx that shot well - nothing's walking away from that if I do my part.

As for temp stable, I don't get too fired up about that. If you run the numbers, temp instability equates to a difference of <2" of drop at 500 yards. If I could shoot better than that, I might be concerned about temp instability.
 

Etxaggie

FNG
Joined
Dec 7, 2020
Messages
22
I run h4831sc with the 140 AB and 162 ELD in Peterson Brass through a Kimber Montana. Excellent results.
 

SloppyJ

WKR
Joined
Feb 24, 2023
Messages
681
I've just started working mine up but I think I've narrowed down my starting load to 59gr of 4831sc, WLR (because that's all I could find), under a 160gr partition in peterson brass. Only one 3 shot group tested but I had 0.29" at 100yds. I think I was 20thou off the lands.

If I can get more results like that on my next range trip, I'm not changing a single thing. This is out of a production rifle too.

The only problem with my 280ai is that it seems to be the sweet spot for rifles. I really want to build a rifle for a larger caliber but everything I look at seems to lead me back to comparing it to my 280 and deciding that it isn't that much better. Guess that's not a bad problem to have. Maybe I'll just build another one.... or a 7PRC
 

Bomberodevil

Lil-Rokslider
Joined
Feb 17, 2018
Messages
103
Location
Phoenix, AZ
I've just started working mine up but I think I've narrowed down my starting load to 59gr of 4831sc, WLR (because that's all I could find), under a 160gr partition in peterson brass. Only one 3 shot group tested but I had 0.29" at 100yds. I think I was 20thou off the lands.

If I can get more results like that on my next range trip, I'm not changing a single thing. This is out of a production rifle too.

The only problem with my 280ai is that it seems to be the sweet spot for rifles. I really want to build a rifle for a larger caliber but everything I look at seems to lead me back to comparing it to my 280 and deciding that it isn't that much better. Guess that's not a bad problem to have. Maybe I'll just build another one.... or a 7PRC
I agree, the 280 AI is a pretty good compromise of bullet weight, velocity, KE, and efficiency. I load the 160 AB and the 162 ELDX, 58.8 grains of H4831for the ELDX, for temp stability and consistency and giving up a bit of speed. Fed 210 primer, .030 jump, shoots 3-round groups at or below .400. Deadly cartridge.
 
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jc_at_aq

FNG
Joined
Aug 23, 2023
Messages
10
I'll be working up a load using H4831SC with 145 LRX bullets once my 280ai is done, mainly because I have a big pile of both components for my 7mm RM.
 

SCHUNTER73

Lil-Rokslider
Joined
Aug 25, 2021
Messages
161
Mine likes 162 gr ELD-X with Ramshot Hunter. I’ve also used Retumbo with similar results.
 
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