Home Forums Reloading Big Game Rifles Load Data 280 Ackley

I have no history with which to form an opinion of how this rifle responds to other 'book' loads.... so I'll ask another question or two.

Say you reached book max (64ish grains?) and velocity was 2875... you saw no signs of pressure at all, and everything looked normal. Would you add a half-grain and clock it? Now it's 2930... nothing funny, brass looks/measures the same. Another half-grain?

I would refer to other loads in the same rifle. If they too show a propensity for retarded velocity with book loads... I'd up the ante and 'assume' I'm in the same neighborhood as the 'book'. If other loads got book velocity with book loads.... I'd maybe write off the powder and look elsewhere.

What I'm asking you is.... how do you decide when enough is enough? The book load.... the velocity.... the 'pressure' as interpreted by your experience and the advice of others?

Pressure trace will be cool indeed... and I'm sure will open eyes. Most of us knuckle draggers will never enter this realm however... I'll just have to rely on my brass to tell me when I'm leaning a little on the east end of the powder measure.

On a 65K cartridge I'm not sure I would add powder beyond max book loads.
On a 61K cartridge I probably would provided the rifle is strong enough and modern enough to do so.

Now if I have a PT transducer glued to the barrel I'd probably keep adding powder until I began to see "traditional" pressure signs just to see what pressure is produced when these pressure signs are seen.

That will be interesting to see.....

Lefty thanks for that information. Simply another example of the wide differences to be encountered between various barrels chambered for the same cartridges and something I've observed numerous times over the years ( not only with 7mm's, but with 270's, 30 caliber,and on up the ladder).More time spent with 30 caliber and under has shown more examples of it, but it exists elsewhere, too.

When I see us depending heavily on printed data and predicting absolute pressure results for a given cartridge, I blanche a bit....and especially when I see wild claims for smaller cases being the "equal" of larger cases, using pressure figures "assumed"(not known)I become even more skeptical and know immediately somethin ain't right.

I have no doubt I have run a 7 Rem Mag over SAAMI spec at times...and at other times well under.I still have not had anyone provide a reasonable explanation for the the fact that the Nosler manual shows,across the board,mor velocity from a 24" barreled 7 RM than a 26" barreled 280AI.

I think this stuff about loading one to 65,000 and the other to 61,000 and comparing them is an utterly silly conversation because the proponents don't have a clue what the pressures are in the respective barrels for each,other than reading about it.


They wouldn't get to first base in a courtroom doing things this way...which is why I find it so ridiculous.But courtrooms deal with "truth".... or try to....and reloading forums frequently deal in wishful thinking coupled with delusion and agendas.

Oh silly, silly Bob....... don't you know affect and unicorn farts are good for an additional 50-75fps?

dogshooter I have seen those differences between steel buttplates and cushy recoil pads as well....

Good stuff there Left-thx for sharing

Dober

Since Lefty C posted RL17 and I had next to no luck looking for data when I wanted to try it I'll add that I stopped at 58.5gr RL17 and 140gr NBT with light ejector mark.

7mmf,

Since he burning rate is close I used 4350 data.

My rife must be "slow" bcause Iam etting no where near the velocities that most are posting here.

LC

I also used 4350 data to get rough starting point and loaded up a ladder to get a max in my rifle. I didn't chrono that load. I have this weird thing about chrono'ing starting loads because I'm afraid I'll steer away from a powder that might produce good precision but might not meet my velocity expectation.

That day I was starting over on my loads because I had just started coating bullets with hBN. I tested RE17, RE19, and RE22. My best starting loads were the RE19 & RE22. RE17 did not produce nearly as tight nodes as the other two so I chose to save it to play with for another rifle. RE22 has been a proven performer in that rifle since I built it back in '99-2000 timeframe.

Here, here... I've been using a load that dogzapper suggested in my Ackley lately which is 60 grs of IMR-4831 with 140 gr Nosler BT's. Very, very accurte with no "traditional" warning signs.

140 NAB, 63.3 grns of VV N165, fed 210m, gives a velocity of 3206 from a 24 3/4" tube. Pressure signs are non existant and brass life is forever. Accuracy is consistantly sub .5 MOA . As good as a 280AI gets IMO when running 140 grain pills

Have you noticed any temp sensitivity with that VV-165 ? I hear lots of guys say that 165 is a great powder for the Ackley and I have a bunch of it that I was using in my 300 WM. Someone here was reporting that they weren't getting alot over 3000 fps in their 280 Ackley with 140's using that load in a 24" barrel.

Its usually summertime when i do load work/sight in. Never had a bullet fail to hit where the crosshairs are. Never noticed anything different as to pressure signs throughout the year with that powder. Louisiana gets as good as it gets for offering weather from damn hot and humid to colder than dangit. Again never noticed any differences when weather changes

Wasn't is Melvin Forbes who wisely stated that there isn't much in the world that cannot be hunted with a 140 grain 7mm bullet at 2900fps?

There are two very different schools of thought when it comes to stepping up to the next cartridge case size.....

Some handloads are looking for speed and sue the case to push their favored light/medium weight bullet faster and there is a now older, school of opinion that preferred to use the larger case size to propel heavier bullets at the velocities they were familiar with.

The fly in the ointment is that bullet technology is rapidly negating the need for the heavy weight bullets in each caliber.

The game is not over, but the scoreboard is leaning towards velocity over bullet weight, that is for certain.
John

I am a novice reloader. Have 2 280AI's. One is being built and other is being stocked after a recent build. Owned one prior but did not personally load for it. I hit pressure signs (sticky bolt) on my new gun. Was trying it out in an old stock. 75 degree temps and close to the lands. This was with 150 TTSX and 160 Accubonds. Both loads were slightly below published max loads. I just bought a chronograph. Have not tried it as have no cf rifles at home right now. what will the chrono likely tell me about this rifle's performance? Will the below max loads likely be faster than the book or could I just have a chamber/barrel that does not like to be pushed? Hate to ask a dumb question but unsure how to use the chrono as a reloading tool. Know it will tell me speed for ballistic calculation. Is the chrono otherwise there to show unusually high velocity absent other pressure signs as a safety tool? Thanks.

Look at a LOT of data,as much as you can,to get an idea of what the cartridge is capable of in different barrels to get a weighted average of velocities. A pattern will emerge.

Confirm with your own loads and watch the chronograph. Also watch primer pockets and other "traditional" pressure signs. They may not be perfect but they are all you have unless you buy pressure equipment.

Expect anomalies. No two barrels are ever the same, even if from the same maker, chambers cut with the same reamer, same day.

In reading others experiences,toss out the exceptionally high velocities they obtain, and the exceptionally "low". The truth will likely be in the middle range of things.

Remember that within ear shot of this site are (how many?) a few hundred 280 AI users(?). That's a few hundred different barrels, with varying dimensions,cut with different reamers,different mixes of components,fired under different conditions and over that many different chronographs. If results are identical to yours it's more luck than design....but it'll still happen.

Just because someone else gets 3200 with a 140 gr bullet from a 280AI does not mean you will...too many variables.

Never owned one, but seeing 3300 fps from a 140 gr bullet from a 280AI would have me on red alert,whether it showed pressure signs or not.Even larger cases do not alway go that fast in some barrels.

Get some factory ammo in the same bullet weight and see what it does. Word is the 280AI is loaded pretty hot and if your barrel is getting substantially more velocity than the factory stuff from your hand loads, you may want to back off.

Thanks Bob!

True statement right there.