Need help on fire forming 280AI brass

[longbowelk]

I am in the process of fire forming brass for my 280AI original Ackley version. I have done about 12 so far using the cream of wheat method. I went as high as 20 grains of Unique powder but dropped back to 19. I have checked the headspace of these 12 vs one case that was Fireformed using a loaded round and the difference ranges from .01 to .007. I don't see that the COW method is going to do the complete job. I am using new 280 Hornady brass. Here are my questions. ..
Are these 12 ok and ready to fully load according to max loads per say a Nosler manual?
My Sierra 5th edition says the case should be trimmed to 2.515. Mine are at 2.524. Should I trim them prior to reload or after shooting? This is a 26"Shilen barrel.
One final point I would make is when I started the COW I started at 10 grains and moved up a grain at a time. These that were 10 to 13 didn't move shoulders that much so I tried them a 2nd time using the 19 grains. I only did 2 as the primer had backed out so I decided this created a pressure problem.
Any help would be appreciated.

 

[Lefty7mmstw]

I don't like to use breakfast cereal to form brass. I use mild loads in the regular or partially formed brass to make my cases. For your ai I would simply use mild- (read that as start) loads with 280 brass with the bullet seated out to the rifling. You don't have much shoulder engagement with an ai, so the bullet run out can help a lot with minimizing case stretch when forming.
As to case length, make sure your blown out casings are no longer than max. oal... I wouldn't trim short at all until they have seen a firing as an ai.

I am curious as to why you aren't just using nos ai brass??

 

[shortgrass]

I agree, use a load with a bullet. If the chamber is properly head spaced you shouldn't have to jam the bullet. The case should be trapped/captured between the bolt face and the neck/shoulder junction so all stretching takes place at the front of the case. There should be noticeable resistance on the bolt handle when closing the bolt on the parent cartridge in a Ackley chamber. Fire forming with bullets usually give very good accuracy,, so sight it in while fire forming and get yourself a bit of trigger time, ta' boot...... Don't over complicate this, it's just too easy!

 

[Lefty7mmstw]

I agree, use a load with a bullet. If the chamber is properly head spaced you shouldn't have to jam the bullet. The case should be trapped/captured between the bolt face and the neck/shoulder junction so all stretching takes place at the front of the case. There should be noticeable resistance on the bolt handle when closing the bolt on the parent cartridge in a Ackley chamber. Fire forming with bullets usually give very good accuracy,, so sight it in while fire forming and get yourself a bit of trigger time, ta' boot...... Don't over complicate this, it's just too easy!

If he has good resistance when he closes the bolt he won't need to jamb a bullet, but he had mentioned trouble with primers backing out...

 

[longbowelk]

Lefty...This is the original P O Ackley version. The Nosler version is .014 headspace different. I am no expert but have read a ton of info here and elsewhere that it is not advisable to fire the Nosler AI cartridge out of this one. So, I have to FF . I read several articles and watched some YouTube videos on the COW so I thought I would try it. I do plan on shooting some factory 280 plus I reloaded 10 rounds of 280 using 162 grain Hornady bullets and 45 great of IMR 4350 which is in between min and max. I haven't shot any loaded ammo yet, but will soon.

 

[MudRunner2005]

Fire forming with bullets usually give very good accuracy,, so sight it in while fire forming and get yourself a bit of trigger time, ta' boot...... Don't over complicate this, it's just too easy!

This is what I do. But I seat into the lands with light loads to ensure that my cases form with 100% correct headspace.

 

[Lefty7mmstw]

Lefty...This is the original P O Ackley version. The Nosler version is .014 headspace different. I am no expert but have read a ton of info here and elsewhere that it is not advisable to fire the Nosler AI cartridge out of this one. So, I have to FF . I read several articles and watched some YouTube videos on the COW so I thought I would try it. I do plan on shooting some factory 280 plus I reloaded 10 rounds of 280 using 162 grain Hornady bullets and 45 great of IMR 4350 which is in between min and max. I haven't shot any loaded ammo yet, but will soon.

Yep, my brother has two of the nosler ai chambered 280ai's. We've played the game with the 280ai. Nosler had no business changing the headspace from the po Ackley version...

 

[shortgrass]

If there's no resistance closing the bolt on a 'parent' cartridge in an Ackley chamber, it is not headspaced correctly. Over the past 25yrs. I have fire formed thousands (and that's not an exaggeration) of cartridge cases in many different Ackley chambers. From the .22/250 through the .338/06. The info for proper headspacing is readily available from many different sources, including "Handbook For Shooters and Reloaders", by P.O.Ackley. It's, also, easily found on Dave Mansons' web site, if you don't have the books. Ackley designed the chambers so that factory ammo could safely be fired .

 

[TOM H]

I am in the process of fire forming brass for my 280AI original Ackley version. I have done about 12 so far using the cream of wheat method. I went as high as 20 grains of Unique powder but dropped back to 19. I have checked the headspace of these 12 vs one case that was Fireformed using a loaded round and the difference ranges from .01 to .007. I don't see that the COW method is going to do the complete job. I am using new 280 Hornady brass. Here are my questions. ..
Are these 12 ok and ready to fully load according to max loads per say a Nosler manual?
My Sierra 5th edition says the case should be trimmed to 2.515. Mine are at 2.524. Should I trim them prior to reload or after shooting? This is a 26"Shilen barrel.
One final point I would make is when I started the COW I started at 10 grains and moved up a grain at a time. These that were 10 to 13 didn't move shoulders that much so I tried them a 2nd time using the 19 grains. I only did 2 as the primer had backed out so I decided this created a pressure problem.
Any help would be appreciated.

I got a question? Didn't you start last month using Bulleye for fire forming and you had case formed for that chamber?

 

[sable tireur]

longbowelk,

Please check your e-mail.

Regards.

 

[longbowelk]

I agree, use a load with a bullet. If the chamber is properly head spaced you shouldn't have to jam the bullet. The case should be trapped/captured between the bolt face and the neck/shoulder junction so all stretching takes place at the front of the case. There should be noticeable resistance on the bolt handle when closing the bolt on the parent cartridge in a Ackley chamber. Fire forming with bullets usually give very good accuracy,, so sight it in while fire forming and get yourself a bit of trigger time, ta' boot...... Don't over complicate this, it's just too easy!

Since Ackley designed this to fire the parent cartridge I assume it would be ok to reload the .280 up to max on powder(per the load manual for the particular bullet/powder combo). I know most state to load the minimum required powder while FF. Using closer to hunting load or close to maximum powder should be closer to POI compared to the AI loads. Is this a valid assumption?

 

[longbowelk]

I got a question? Didn't you start last month using Bulleye for fire forming and you had case formed for that chamber?

Yes, I did try the Bullseye. I thought maybe the Unique might do better since it was listed as faster powder than the Bullseye plus most have stated they used the Unique. The only case that I have that was formed properly using a parent .280 cartridge is one that the seller gave me when I bought the rifle. I have been using it as a guide to compare my fire forming brass.

 

[wwbrown]

For the original 280 AI I start out with Lapua 30-06 run it through the 280 AI sizer this will put a false shoulder on the brass as it will reduce the neck diameter to a point that is forward of the shoulder. The 280 AI is a little different from most AI's as the shoulder is not just blown out but it is also moved forward that is why the false shoulder is formed, that is why it is easiest to form using 30-06 brass than 280 brass.

With the false shoulder load up medium 280 loads and fire, these rounds can be amazingly accurate so you may want to check the accuracy so you don't just waste the ammo, some people shoot club matches while blowing brass out.

I built a 1,000 yard F-class gun using the original 280 AI, I used the original for two reasons it has a larger capacity than Norma's 280 AI. The second reason for the original chambering is I could start out with Lapua 30-06 brass, my arm has to be twisted very hard to build a competition gun in a chambering I can't use Lapua brass for. I could have used Lapua 30-06 brass with Norma's version also but I wanted the extra capacity.

 

[shortgrass]

Since Ackley designed this to fire the parent cartridge I assume it would be ok to reload the .280 up to max on powder(per the load manual for the particular bullet/powder combo). I know most state to load the minimum required powder while FF. Using closer to hunting load or close to maximum powder should be closer to POI compared to the AI loads. Is this a valid assumption?

I would NOT use the maximum load from a loading manual. Every barrel is different.. Some don't need as much powder as another might to reach "maximum". Start at the minimum load or just slightly above for safties sake. The "max" in the loading manal might be above max in your barrel. When you insert a .280 Rem. case into the chamber is there some resistance felt when closing the bolt? Do you have to "push" on the bolt handle some to get it all the way down? The question is, "did the gunsmith that chambered this barrel adhear to Ackleys method of headspacing, where factory spec ammo will have some resistance when closing the bolt,, or did he not headspace it that way?".