Home Forums Hunting & Shooting Hunting Rifles What Am I Missing 7-08 vs 280 AI??

I have one rifle each in 7-08 & 280 (both AIs) in the works and have been looking over data in preparation for fireforming.

I bought LC cases and Prvi 174 gr FMJs for FF'n cases for each of them and was looking over load data for these combos and am surprised by what I saw.

With 175s Ramshot lists best velocity in 7-08 at 2650 fps, while Hodgdon lists around 2700 for the 280 AI.

Am I missing something? I admit I don't intend to run heavies in them both, but it would seem the larger case would have greatest advantage in the heaviest bullets but these numbers don't show much difference?

What you guys who love the 280 AI using propellant-wise and what are you getting speed-wise?

Just for the record I plan on running 120 & 150 NBTs in the 7-08 & 162 AMs in the 280.

Possibly. Hodgdon used Swift bullets whose jackets are "sticky" and generate pressure sooner.

not much difference between the standard versions of both cartridges,...AI's will have similiar differences.

280AI I like R22 with the heavy bullets and H4350 with the little ones.

4831 and N165 get lots of mention as well.

All other things being equal ie bullet, barrel, loading to identical pressure levels etc, one would expect about 150-250fps more with the larger case.

Yes sir; that is about what I was expecting.

I've got both also. The 280AI definitely out paces the 7-08 in velocity with the correct power/bullet combos. I sure don't need or want to make my 7-08 match it's big buddy. That 7-08 is one of the best and fun shooting rifles I own.

The 280AI is extremely flat shooting and accurate with a little more recoil than the 7-08.

Try H4831SC with those 162s out of your 280AI- gets me to 2950fps. R22 works well with the 168VLDs.

A couple things:

Are you asking about a 7mm-08 Ackley Improved versus a 280 Ackley Improved? Because your post is a bit confusing, mentioning both a normal 7mm-08 and the Ackley Improved version. The difference in the Ackley Improved versions of both will less than 150-250 fps. I would think more on the lines of 100-150.

Using Lake City brass with it's reduced capacity, you will top out on velocity and pressure before more capacious brass. Reduce charges a pretty good amount, both for fireforming and for eventual fireformed loads.

The 280 (and 280 AI) case design has the shoulder further forward than the '06, but necking down the 30-06 brass will hopefully produce enough of a false shoulder to fireform out correctly.

I doubt if the 7-08 AI will give more than a 100 fps improvement, unless pressure is increased significantly. There just isn't that much change in capacity.

'06 brass is shorter than .280 or .270 brass (2.494" vice 2.540" )

Sorry yeah I am building both as AIs, but was comparing book 7-08 Rem to book 280 AI numbers. Thought there'd be more difference than what I am seeing. Guess that just means I need a Kimber 84M in 7-08!!!!

Yeah I intend to leave a false shoulder on the 06 cases due to 280 shoulder. Would the shorter OAL be an issue? I have lots of 270 brass... Should I run that through a 30-06 FLS & neck back down for same-same OAL?

I was gonna dump a grain below max of the parent cartridges for FF'n; standard 7-08 & 280 Rem, that is.

280AI-140NAB, 63.3grn VV N165, 3206fps, < 1/2"@100yds for 5. 24 3/4" tube
I'll not post the load info i used when I had my 26" 7-08AI. It was a bit "warm". Not enough to cause serious concerns, but it could have been backed down a touch. It was very close to my 280AI speed wise. If I did another 7-08AI, it would again have a 26" tube and id have a very hard time deciding between the 140NAB and the 120NBT

I'd be looking for some 280 Rem cases, and skip the 06 cases because they will end up way short!

My 280AI cases were formed from necked up WW 270 brass