280 ackley vs. 7mm remington

[SJB358]

I'm with you RR. I'm always punishing myself for a little bit more. Hence the 35 Newton.

As for the WSM versus any of the others, I believe by the time load falls out, they'll all be close to one another. I run 160 ABs at 3075 from my WSM. It's accurate and plenty good for me. I'd be just as happy were it shooting the same at 2975.

Even having a 7 Rem and WSM, I'd like a 280, 280AI, but before that, the 7 Mashburn will probably come home.

 

[BD1]

Ridgerunner,
Please excuse me because my memory has become a little sketchier as I've gotten older, that said, I don't remember when exactly but I do remember the 7mm Rem.Mag max pressures were reduced down to 61,000 psi. due to pressure spiking issues. Though I'm not exactly sure, it does seem to me that it might have occurred in the 6+ years since this thread was started and EagleEyes comments were accurate at the time he wrote them. I also seem to recall the same thing happening with the .243 around the same time, maybe someone else who's memory is a little better today than mine can add to the conversation.
I've owned and loaded all three cartridges mentioned earlier and my results are about the same as posted above. To simplify things, I've since divested myself of the AI and 7mag and went back to a custom, plain vanilla .280 Rem.
There isn't anything much like the anticipation of waiting for a new rifle delivery, studying load data and getting things ready, I hope your new rifle performs to your expectations.

Best,
BD

 

[Ridgerunner665]

The pressures for the 7Rem were lowered...but it was longer than 6 years ago...don't know exactly when either but I'm pretty sure it was longer than that.

I think a lot of people just plain don't realize that many of the magnum rounds don't run at full pressure...I'm not saying that is the case with Eagleye, he seems pretty knowledgeable...

Further, before it was standardized...nobody much agreed on where to run the Ackley....some said 60k, some said 65k....Ackley said, as long as the bolt stays in the rifle its OK, lol.

Myself, I'm gonna roll with 61-63k...I think I can do what I want to do at that pressure and not beat the brass up too bad....just gotta be picky with the powders I use.

 

[Darkhorse]

The pressures and loading data for the 7Mag were reduced pre '74, I can be more exact later this evening when I go out to my shop and retrieve more data. I'm basing this on old loading manuals which addressed this issue.
Speer manual # nine says this; "Loading data for this high intensity cartridge has varied a great deal in past years. This wide difference in recommended loads is due mostly to variations in chambering and rapid throat erosion in test rifles." Indeed, the data in this edition is even a little lower than what we see today. Panic attack I guess as I have seen rifles that had case head separation with factory loads. That's a good reason not to shoot belted magnums from another rifle.
Prior to these revelations some of us were shooting loads much hotter than today's loads which were deemed "safe" at the time. My rifle was one of these and actually shot better at these higher loads. I think I'll keep her.

 

[BD1]

Thanks for clarifying fellas......I thought I remembered something about it, not when....... :shock:

 

[Bruce Mc]

I've never owned or loaded for a 280 AI but I have loaded a bunch of 160 accubonds in 7mm Rem mag. Quick load shows 3004 fps with 69.2 gr of H1000 at an estimated 55336 psi. That load only chronoed at 2900 or so from my rifle. I cannot speculate on the pressure generated by my load of 74 grs. of H1000 that created about 3080 fps from my 26" model 70. But I have not worn out any brass with that load, some brass is up to five reloads, and my primer pockets are still tight, and best of all, it shoots "bug holes". And on a side note, I'm peved because I missed out on the last bunch of 160 AccuBond blems at the proshop. (I'm using formed and neck sized brass at 3.350 oal these days)

 

[30-338]

The pressures for the 7Rem were lowered...but it was longer than 6 years ago...don't know exactly when either but I'm pretty sure it was longer than that.

I think a lot of people just plain don't realize that many of the magnum rounds don't run at full pressure...I'm not saying that is the case with Eagleye, he seems pretty knowledgeable...

Further, before it was standardized...nobody much agreed on where to run the Ackley....some said 60k, some said 65k....Ackley said, as long as the bolt stays in the rifle its OK, lol.

Myself, I'm gonna roll with 61-63k...I think I can do what I want to do at that pressure and not beat the brass up too bad....just gotta be picky with the powders I use.

Nosler has been publishing load data for the 280 Ackley Improved long time before it became SAAMI Spec. Nosler Manual # 4 1996 and this is from that manual on pressure.

"There is no established max pressure limits for the 280 Improved. These loads do not exceed SAAMI max average pressure limits for the 280 Remington (60,000psi)."

Sierra had reloading data for same case in their manual.

 

[Darkhorse]

I haven't found any data as to when SAAMI reduced the pressure on the 7mag, just vague references to it having done so. Apparently the .243 also suffered this fate about the same time. Most reasons given were pressure spikes. Something I never encountered in either my 7mag or .243.
Modern methods of measuring pressure may be a main reason, along with varying chamber specs. and loads that were a little too hot from the beginning.
I've said that I have loaded my 7 a good bit over todays max. loads, but still within the old loading data with no pressure signs. While this is true I also realize that this was back before I learned to measure case head expansion while working up loads. Today this is the first thing I do when checking pressure in load development as it will show a measurable expansion prior to the older visual indicators becoming present.
I've shot the 7mag since 1983 and never found it wanting for performance. Both locally and in the west for elk shooting 175 gr bullets. I no longer push the envelope with the 7mag as I bought a .300 Win. for those purposes.
I've considered the 280 and 280AI but found them too similar to what I already owned to offer any benefit. Except for doing away with the belt.

 

[orchemo]

I just want to say.....i am willing to try out your Nosler TGR 280AI Sporter.

Maybe after shooting it for a couple years hunting with it, I would grow more appreciative of the caliber.

So, who ever wants to ship me theirs rifle, send me a PM

Eric

 

[DrMike]

I just want to say.....i am willing to try out your Nosler TGR 280AI Sporter.

Maybe after shooting it for a couple years hunting with it, I would grow more appreciative of the caliber.

So, who ever wants to ship me theirs rifle, send me a PM

Eric

As I've often noted, the generosity of those posting here is simply breath-taking. Such consideration! Such selfless investment! Eric, I'm humbled to think of your sacrificial attitude. :grin: