.280 Ackley Improved
 

I have a question for you guys,

I have a new .280 Rem AI and I loaded up 100 rounds of .280 Rem loads to fire form. I used new Rem brass, 150gr Winchester Power Points (cheapest things I could find) and approx. 50.6grs of RE-19, and Federal GM210M primers.

My question is this. Should I expect any type of accuracy while fire forming these rounds? I am not talking under 1/2" groups or anything like that. The rounds are very inconsistant. I am not sure if it is because the parent case doesn't fit snugagainst theshoulder of the Ackley or possibly something else. Any help you can provide I would apprectiate it very much.

Thank you

RE: .280 Ackley Improved
 

For one thing, you didn't tell us how you loaded your brass in regards to OAL. Where did you seat the bullets off the lands? Another thing... until you get those cases fireformed to your chamber, I wouldn't expect a lot in the accuracy dept. I would suspect, however, if you were off the shoulder to amount to much, you would be getting early case separation at the least, and quite possibly some gas leakage and denting of the case shoulder and body. Any signs of this?
My manuals don't list RL 19 for the 280 with 150 gr. slugs. I personally have had my best luck with IMR 4350 in the .280 Rem.

RE: .280 Ackley Improved
 

Thanks for the reply

Sorry I forgot to add the OAL of 3.320.
While fire forming there were no signs of of dents, case seperation, and I didn't notice any discoloration around the neck.
I just loaded up about 9 different powder (weight combos for three different bullets (HDY 139 sst, SMK 168,and NOS 150) I Used both IMR 4831, and H4831SC(Nosler). I tried mid power loads and gaining in .5 incriments. C.O.A.L is what is listed in the manuals.

I am hoping that I will see better groups now that I have fire formed all the rounds I have. I also bought some factory Federal 140 gr Barnes to see if they work.

Thanks again for your help.

RE: .280 Ackley Improved
 

I doubt very much that you'd get better accuracy if you were firing factory loads to get brass, either. You can't really expect much in the way of performance until you actually work up a load for that gun.......

And to do that, of course, you have to have some formed brass.........

With a PROPERLY CUT Ackley chamber, you should NOT have any headspace problems while firing factory 280 ammo or brass. The only difference is that the Ackley case has a sharper shoulder angle and the shoulder is larger in diameter. The headspace specs are identical between the standard and AI version.

RE: .280 Ackley Improved
 

Yes. My fire-form loads often shoot as well as my AI loads.



In a properly headspaced AI chamber, the parent case (no bullets) should be snug in the chamber. An AI chamber is typically .004" shorter than the parent case so that factory ammo can be safely fired. There should be some resistance when you try and close the bolt.

If your chamber is a little loose, you can overcome this by seating your bullets a little longer. Seat you bullets so they engage the rifling. This will hold the case head firmly on the bolt face during the fire-forming process. Again, there should be some resistance when you try and close the bolt on your fire-form loads.


After fire-forming, be sure to adjust your sizing die to that it properly sizes the brass for your particular chamber.

RE: .280 Ackley Improved
 

If the fire form loads have a headspace issue try using a 30 cal neck expander then when you neck down to .284" set the die so the case headspaces on the small shoulder formed from the 30 cal expander. A buddy has a 270 Gibbs, the case shoulder on that round is moved more forward than the Ackley improved and that is what they did to get the cases to fireform.

RE: .280 Ackley Improved
 

That's basically what I used to do to make .280 brass out of .270 Win. years ago when the .280 stuff was scarce........

RE: .280 Ackley Improved
 

This would be a wise practice for making .280 cases from .270 brass, as the .280's headspace measurement is oonger, the idea being to prevent some turkey from chambering a .280 round in a .270 chamber. If you used .30/'06 cases to make .280 brass, all that need be done is size the neck down until the case will justy permit the bolt to be closed with a little extra force on the bolt handle.

It could be done with .280 brass in a .280 AI chamber as well, but would not be necessary if the .280 AI chamber is properly cut. The headspace specs for the standard .280and the .280 AI are the same. IF you were forming 7mm Gibbs cases, it would be a different story!

RE: .280 Ackley Improved
 

Agreed....

RE: .280 Ackley Improved
 

Thank you all for your time to reply. I will check the new loads this weekend and see if it shoots any better. Maybe with the full power loads it might do a little better. That's what I am hoping for anyways.

Thanks again