Case capacity 280AI

newmexkid

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So, the other day I fireformed 48 cases with 52.0 grs. IMR 4350 and 140 gr bullets. According to the Sierra manual, this was about 2 grs. under max for a 280. Today I took a new 280 case and filled it up to the top with 4831sc and did the same with a fireformed case. The fireformed case held almost 3 grs. more of the powder. Would you say this sounds about right? Been loading for many years but, this is my first Ackley.
 
So, the other day I fireformed 48 cases with 52.0 grs. IMR 4350 and 140 gr bullets. According to the Sierra manual, this was about 2 grs. under max for a 280. Today I took a new 280 case and filled it up to the top with 4831sc and did the same with a fireformed case. The fireformed case held almost 3 grs. more of the powder. Would you say this sounds about right? Been loading for many years but, this is my first Ackley.

This may not help. I shoot 280AI Spec and I use Nosler brass and I do have wildcat 280AI non spec and use Rem brass. I took new cases 280/280AI and I filled both with IMR-7828ssc and difference was little over 4 gr.

I have 35 WhelenAI and I purchase about 300 new Rem 35 Whelen cases. I took new case/fired form and difference was little over 4gr and filled using R-15.

I've got 243AI and that one difference is 2.9gr.

I do think it varies
 
I think you have to preform a better test for yourself...
Unless you are cramming that powder in to fill air pockets...just too many air pockets....i would do a water test...or use as absolutely fine powder to do the test....make sure to tap it so it all lays down tight or your wasting time....
In my 280ai I am using a lite load of 55gr of 4831sc in multiple fired 280ai nosler brass...2630fps....22" barrel...168lrab...rifle is a mtn rifle noodle barrel.....over 55gr and the scope wears out the hat brim too quickly.......
 
I think you have to preform a better test for yourself...
Unless you are cramming that powder in to fill air pockets...just too many air pockets....i would do a water test...or use as absolutely fine powder to do the test....make sure to tap it so it all lays down tight or your wasting time....
In my 280ai I am using a lite load of 55gr of 4831sc in multiple fired 280ai nosler brass...2630fps....22" barrel...168lrab...rifle is a mtn rifle noodle barrel.....over 55gr and the scope wears out the hat brim too quickly.......
I'll do a water test tomorrow and also a test with finer powder.
 
I just came across this this morning on volume of cases. I looked back some, and came across this, but a little late, but. Using powder to determine volume I don't think that very accurate. Volume by fluid would be far more accurate. Powder doesn't stack the same every time. For a long time I use to weight my cases to gather the same or close to same weight cases. Determine that was a mistake. Now use volume by water to get those figures.
 
Quick question....does the old version of ackley hold more volume or less than nosler Sammi verson
 
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If done properly, both chambers are the same as both should have a crush fit at the shoulder neck junction of the parent 280 Rem case.

 
I don't know of any other 280AI case, design. (that doesn't mean there wasn't) I hadn't done any exploring on the case other than when I was coming up with a wildcat cartridge using the 280AI case as a base for setting up a reamer. The case is just a little longer to shoulder that like 25-06AI or 30-06AI. I looked at as away to get more powder into the case. Now I really glad I did, because for the case manufacture the inside volume is a little less. I further don't know if that going to be any big deal either.
 
Quick question....does the old version of ackley hold more volume or less than nosler Sammi verson
On my spec 280AI and wild 280AI I can chamber new 280AI Peterson case in both rifles but once fired they won't fit each other chamber. My self I used different body dies and I think Redding dropped that body die for wildcat. Wildcat was listed as 280 Remington IMP 40 and new was 280 Ack IMP.
 
That more than likely because of difference reamers. Now I use the dimensions from Sierra Reloading Manual to set up the reamer. Only I reduce the neck area to a more control expansion of the neck instead of the normal size. So I now cut my necks to .0125 thickness. I was trying to achieve .013 but miss that. If you watch the video from Seabeeken I believe expands the case. I have 4 280AI bushing dies to bush the neck down to where I need it.
 
On my spec 280AI and wild 280AI I can chamber new 280AI Peterson case in both rifles but once fired they won't fit each other chamber. My self I used different body dies and I think Redding dropped that body die for wildcat. Wildcat was listed as 280 Remington IMP 40 and new was 280 Ack IMP.
There were several similar wildcats in different calibers that had 40 and 26 degree shoulders. I recall seeing *** ackley and *** RCBS, just cant remember the name of them but only difference was shoulder angle. I know Manson reamers makes head space gauges for ackley cartridges that have the .004 crush fit built into the gauge. He is the only one I know of that does that.
 
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