.280AI Loads

williaada

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Looking to get some information on a new to me .280AI. I am going to use it out west for elk, deer, and pronghorn. I do hand load, I will not be looking to take a shot past 450yrds. Thanks hanks for your help.
 
My two cents: If you like lead-free bullets, try the 145 Barnes LRX. If you like lead, start with a 150, or 160 grain Accubond. Any of those should have you set for anything.
 
Oh man are you going to love that rifle. What make, model did you get? Of course work up to this load, but this is what I am using in my 280 AI which is a Winchester Model 70 Classic Sporter that I had customized and chambered for the 280AI.

Winchester Brass
Federal 210 Match Primer
IMR7828SSC - 64.5 grs.
Nosler 140 gr. Accubond or Partition

This load worked equally with both bullets and they shot nice groups. No pressure signs. Since I started hunting with this rifle I shot a nice big old cow elk with one shot at 450 yards. Later in the season I shot a whitetail buck, one shot at about 200 yards. Next year it was an antelope one shot at 300 yards. Last August I used the 140 gr. Accubond on my grizzly bear hunt on the north side of the Brooks Range in Alaska. I got a beautiful old bear and took him with one shot at 158 yards. I hit him tight behind the right shoulder in the lungs and the bullet exited the off-side. At the shot the bear spun 180 degrees into the shot and did two simultaneous somersaults and was dead. He never moved again. I'm thinking I might have to keep this rifle.!!

David

1587252726759.png
 
 
Oh man are you going to love that rifle. What make, model did you get? Of course work up to this load, but this is what I am using in my 280 AI which is a Winchester Model 70 Classic Sporter that I had customized and chambered for the 280AI.

Winchester Brass
Federal 210 Match Primer
IMR7828SSC - 64.5 grs.
Nosler 140 gr. Accubond or Partition

This load worked equally with both bullets and they shot nice groups. No pressure signs. Since I started hunting with this rifle I shot a nice big old cow elk with one shot at 450 yards. Later in the season I shot a whitetail buck, one shot at about 200 yards. Next year it was an antelope one shot at 300 yards. Last August I used the 140 gr. Accubond on my grizzly bear hunt on the north side of the Brooks Range in Alaska. I got a beautiful old bear and took him with one shot at 158 yards. I hit him tight behind the right shoulder in the lungs and the bullet exited the off-side. At the shot the bear spun 180 degrees into the shot and did two simultaneous somersaults and was dead. He never moved again. I'm thinking I might have to keep this rifle.!!

David

View attachment 136864
Not that I'm surprised they worked well (I've seen that bullet do great things), but it took some stones to bring 140 accubonds on a Grizzly hunt!
 
Looking to get some information on a new to me .280AI. I am going to use it out west for elk, deer, and pronghorn. I do hand load, I will not be looking to take a shot past 450yrds. Thanks hanks for your help.

I load for a few 280ai rifles, own (3) at the moment. I picked up a first generation Kimber Montana 280ai in early 2017 as I am always looking for that perfect mountain rifle. For this rifle, I decided to start from scratch with my load development instead of using my tried-n-true previous loads.

20170525_215718.jpg

Results copied from my 2017 reloading log:

2017 Elk Rifle

Rifle: Kimber 84L Montana

Chamber: 280 Ackley Improved

Scope: Leupold VX3 2.5-10x40

Barrel: 24”

Brass: Nosler

Primer: WLR

Powder: IMR-7977

Final charge: 62.75 grains

Case fill: 102%, compressed load, must tap case to settle powder with slight crush while seating

Bullet: 160 grain Nosler Accubond

COAL: 3.340”, .001 off of the lands

Group: .87”, average over (5) three shot groups @ 100 yds

Velocity: 2,913 fps, average over (5) three shot groups @ 15’ from muzzle

Temp: 50 degree average

Wind: Slight breeze from bench to target

NOTES: Max load in this rifle. Max COAL for this rifle using 160 grain Accubonds. Recoil did reduce COAL by .0005 per round fired but did not seem to effect accuracy of the two rounds feed from the magazine.

Hunting Update: 2017, cow shot broadside at 27 yards, complete pass through, cow ran 40 yards and died running. Bull shot slight quartering away at 278 yards, complete pass through breaking opposite shoulder, bull collapsed on impact and rolled down the slide.


Thoughts: Finally found my Mountain Rifle and load……now what?????

Remember to always start low and work up to your rifle's MAX load!
 
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I am messing with RL26 and 160g partitions. 61g got us a hair over 3100fps out of a 26” barrel. Fed 210m primers were still round on the edges.

Haven’t done accuracy testing yet so more to follow.
 
I messed with the 145 lrx with Rl-17, H4831sc and rl-26, my rifle didnt like any off those. I have some 143 hammers loaded up with RL-26 to test when I get a chance.
 
I am messing with RL26 and 160g partitions. 61g got us a hair over 3100fps out of a 26” barrel. Fed 210m primers were still round on the edges.

Haven’t done accuracy testing yet so more to follow.
Careful! 160gr at 3,100fps is flat out cook'n for a 280ai. Pressure must be high, even with the long burn curve of RL26. Partitions usually shoot very well when pushed hard. Please let us know how the range test turns out.
 
Careful! 160gr at 3,100fps is flat out cook'n for a 280ai. Pressure must be high, even with the long burn curve of RL26. Partitions usually shoot very well when pushed hard. Please let us know how the range test turns out.

I did a lot of reading on it and tested up to 61.4g. It didn’t show any signs of pressure. The primer still round surprised me. Federal primers are so soft they normally flatten pretty quick.

That speed may change as the barrel get more rounds thru it. It only has 15 on it so far.
 
I did a lot of reading on it and tested up to 61.4g. It didn’t show any signs of pressure. The primer still round surprised me. Federal primers are so soft they normally flatten pretty quick.

That speed may change as the barrel get more rounds thru it. It only has 15 on it so far.
I'm sure that you know this,,,,, but "Improved" case design will minimize the tried and true pressure signs, such as flattening of the primers. I would measure the base of your fired cases just ahead of the web to see how much expansion is occurring. While RL26 is a great new powder, it is not magic!
Nosler 280ai 160gr.JPG
Over the years, I have wrecked a lot of brass trying to reach Nosler's listed "MAX" velocities. Please proceed with caution!
 
I appreciate your concern, but if I didn’t think it was safe I wouldn’t of tried it or posted it.
As an aside for newer reloaders - never start with somebody else's posted final round. Always work up from a starting point at least as low as a reliable reloading manual mid-point. Each gun barrel chamber is a little different. I had a .270Win that couldn't get past load book midpoint without blowing primers - must have had a super tight chambering.
 
As an aside for newer reloaders - never start with somebody else's posted final round. Always work up from a starting point at least as low as a reliable reloading manual mid-point. Each gun barrel chamber is a little different. I had a .270Win that couldn't get past load book midpoint without blowing primers - must have had a super tight chambering.

Or tight bore, or short throat, or the reamer they cut the throat with was worn and you had an abrupt throat angle, or your brass was thick, or your primers were soft(Winchester), or your lot of powder was a little different than the lot that was used when they printed the manual. Hodgdon has completely changed powders without changing the label more times than I can count. They live by the idea that if a batch of powder is within 5% of the goal burn rate, and 5% of the goal energy density, and the handloader reduces all loads by 10%, then everything should be okay.

Never start with any book max, never start with someone else’s data. All barrels are different, but all lots of powder are different too.
 

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