Range Report 280 VERTICLE DISPERTION

goober

Sergeant
Full Member
Minuteman
Jun 13, 2008
195
0
62
Auckland , New Zealand
I am loooking at a new build for my rifle which doubles up for Fclass and general long distance shooting out to 1000 yards .I am looking at the .284 shehane and the 280 and 280AI.comments have been made about the two different cartridges , 1/ -longer and thinner compared to the stubbier case , which people have said the 280 case would give more verticle dipertion than the stubbier case due to the taller thinner powder coloum .The .284 Shehane takes about 3.5 grains more powder than the straight .284 and in a 28inch barrel should give around 2900 plus fps using a berger 180 gr vld -killer BC on this baby. Anyway looking for those with experiance with these rounds please .I am shootin a Barnard short action and will single feed this round so to get the 3.2 " length needed .I have never shot a 7 mill round so your imput would be welcomed
 
Re: 280 VERTICLE DISPERTION

My soninlaw shoots a 280 Remington and loves it!! With that being said I am looking at building a 7MM also and have decided on the 284. I have a short action and will single load it also.

From all my research I think the 284 is the way to go. The other 7MMs are great rounds also but from what I have read I have to go with a 284 or maybe the Shehane.

I esp think the 284 will be better in the short actions. If I was building a hunting rile I would go with a 280 but for target shooting and 1000yd work the 284 seems to be the way to go. This is just my opinion on it and you know what they say about opinions!!!!
 
Re: 280 VERTICLE DISPERTION

My research into LR-capable projectiles of between 120 and 175gr and published .280 Rem load tables suggests that at realistic muzzle velocities, one can expect a round to arrive at 1Kyd running at least at transonic speeds, maybe at 1300+fps, with between 29 and 36MOA of elevation cranked in above a 100yd zero. I think that with an appropriately longer (28" or better) and judicious load development, this can be improved upon. My judgement puts H4350 and 120-150gr projectiles in the most efficient and flatter range. For now, I'm limited mostly to speculation, but having fired the Hornady 139gr SST Custom factory load, I would feel confident in attempting defeating steel at 1Kyd with the cartridge.
 
Re: 280 VERTICLE DISPERTION

I have a .280 AI that is pushing a 180 grain Berger at 2940 out of 28 inch stainless PAC-NOR. I only need 22 moa to reach 1000 at this altitude. It shoots about .6 moa and if I had time to make a few adjustments I think I could tighten it up.

If I had to build this gun again I think I would go for the .284 and run it loaded long in my long action Rem. Brass prep with the AI is a pain in the ass. You can buy AI brass from Nosler but it is way expensive.
 
Re: 280 VERTICLE DISPERTION

Bigbore I would have thought you just fire form the 280 to it new angled shoulder and that was it other than if you neck turn --were getting lazy these days huh LOL .The 284 would have trouble getting those speeds you currently have in a 28 inch barrel without some brass straining hard.The Sheane will do it I believe from my reading -I am trying to find out if it is more inherintly accurate than the 280 A1.
 
Re: 280 VERTICLE DISPERTION

Fire forming is a real pain, I am pretty time limited with work and would rather just buy the brass load it and go.
Plus the idea of having to run the extra rounds through it and shortening the life of the barrel doesn't please that much either.
As far as accuracy goes I have fired 6-8 inch groups at 1000yds on snowy days with no mirage and no wind. It was a great day for shooting.