Ok, I have depleted my store of 4831sc, and it doesn't look like there will be any available any time soon.

So, I found a supply of 7828ssc and bought 4 pounds. It should be a good backup for my 300 WM as well.

Anyone use this powder with a 160 in their 280 Rem? Any help with a starting point would be appreciated. I found data for 7828, but I know that the ssc version acts a bit differently. My bullet for this is a 160 GK(1920), and my bbl is 22 inches.

Thanks!

I've used 7828ssc with a moly 162AM in the .280 to get ~ 2920 fps, using published data and a 22" barrel. Just use 7828 data, it's interchangeable.

7828SSC works great with 175gr bullets in the .280 Remington as well. If you have the need for such a thing.

Going to load a few tomorrow and test them out on Wednesday. We'll see how it goes.

I load the regular version of IMR 7828 with a 154 gr bullet. Its outstanding. That load charge should be 58.5 grs.

Perfect!

It's very good in my two .280AI. Good accuracy and velocity. Seems to work better with heavier bullets, 160s and up.

I use it with 160 partitions in my 280AI. Its the best powder I've used with that bullet/rifle combo.

Thanks, guys. This is what I was hoping to hear!

I worked up to the max in the #8 Nosler manual. I got the speed but was not able to find a sweet spot for accuracy. Brass was nickel Winchester, WLR primer and 160 gr. Speer Grand Slams. Gave the long discontinued Winchester WMR a shot, pun intended and got the same velocity (2910 FPS) with .75" groups on average. Guess I'll stick with that.
Paul B.

I have yet to find that sweet spot of accuracy using 7828 in my 280's.

Funny, after I loaded my first batch of test loads, I wondered if I should have used Federal 215, instead of CCI LR. I'll try these first, and see what happens. I'm using Nosler data as well.

I use standard Winchester Large Rifle in my 280 with IMR 7828. I see no reason to try a Magnum primer with the results I get.

anyone try it with 150's out of a 280?

Though they will give similar velocities you may want to treat IMR 7828 and IMR 7828 SSC as separate powders. In a few rifles I’ve seen different accuracy with the two powders.

IMR 7828, 59gr, 150 Partitions went 3/8” for three shots @ 100 yards

So, I finally got to the range. I took four loads with me. All with 7828ssc, 160 SGK sitting .010 off the lands and grooves. 57, 57.5, 58, 58.5(max)

The 58.5 was the most accurate load, but it also flattened my CCI primers.

58 was good too, but my primers were still looking a bit over pressured.

57.5 was ugly. 3 inches at 100 yds

57 was weird. Three, 3 shot groups. The first two would touch, then the third would go 2 inches right. I did that with three separate groups!

What threw that third shot right? It was about 50 degrees out, and I'm shooting a stainless, 22 inch Remington mountain rifle contour bbl.

If you are two in and then one out, try seating deeper in 1/4 turn increments.

That's the other thing...seating depth. Max SAMMI is 3.330. I'm contacting the lands and grooves at 3.250. So, my COAL is 3.240. this is a factory Remington barrel.

I tried out some IMR-7828ssc for the first time in a 280 rem mountain rifle. I stumbled upon someone who really wanted to sell a bunch of heavy 7mm bullets in various quantities at a gun show. One of the items was a partial box of 175gr Sierra soft point boattails. Not my first choice in this caliber, but definitely something fun to try. Book maximum for a 175 gr Nosler Partition is 57.0 grs of said powder, so I loaded 10 rds with 3.348" overall length in Norma brass and headed to the range. The chronograph registered 2758 fps with this load, and I thought the load was a bit hard on my brass, so I think it would be best at 56.5grs for a bit less velocity but still over 2700fps. The Sierra's are once again very accurate. 4 shots in a good 1" cluster, and i pulled one off to the left. Easy to do in this light rifle. Overall I'm impressed with this powder and may go buy it all. There was 5lbs sitting on the shelf at this GS