243 Win Ackley Improved primers.

victorc

Active Member
Joined
Apr 18, 2009
Messages
26
Location
Northern Utah
This 243 Winchester AI project is my first with a wildcat requiring cartridges to be fire formed from another cartridge. In this case the 243 Winchester. Today was the first to begin the process.

Each shot produced what seems to be a perfect Ackley Improved cartridge. The only thing that seemed odd is the primers backed out of the pocket a bit. I don't know what this means. The fired cartridge was easy to extract from the chamber. There are no extractor marks on the base, nor is the primer flat or cratered. Any ideas what might be causing this, and is there reason for concern? My load is listed below.
* New Lapua 243 Win brass
* Federal 210 primers
* 47.0 grains H450 powder
* Hornady 90 grain ELD-X bullet
* COAL = 2.70
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GLTaylor

Well-Known Member
LRH Team Member
Joined
Oct 11, 2019
Messages
1,507
Location
Cedar Bluff, Al
Fireforming is easy and simple. If you have a correct AI chamber, the factory round should fit with a slight crush fit. This generally holds the case against the bolt face during fireforming.
You rarely fireform fully with one firing. It usually takes 2 to complete the process. The primer protruding means the case wasn't fully compressed between the shoulder and bolt face.
The easiest way to fireform is back off the load a couple of grains and seat the bullet firmly into the lands. This holds everything in place during fireforming.
 

victorc

Active Member
Joined
Apr 18, 2009
Messages
26
Location
Northern Utah
This 243 Winchester AI project is my first with a wildcat requiring cartridges to be fire formed from another cartridge. In this case the 243 Winchester. Today was the first to begin the process.

Each shot produced what seems to be a perfect Ackley Improved cartridge. The only thing that seemed odd is the primers backed out of the pocket a bit. I don't know what this means. The fired cartridge was easy to extract from the chamber. There are no extractor marks on the base, nor is the primer flat or cratered. Any ideas what might be causing this, and is there reason for concern? My load is listed below.
* New Lapua 243 Win brass
* Federal 210 primers
* 47.0 grains H450 powder
* Hornady 90 grain ELD-X bullet
* COAL = 2.70
View attachment 242525
View attachment 242526View attachment 242527
Got the message. Understood and appreciated.
 

Tiny Tim

Well-Known Member
Joined
Jan 26, 2015
Messages
905
Your load looks about right. You could try a faster burning powder but that would only mask the problem. What you have going on is good in the sense that it has identified an incorrect headspace problem, whether caused by the chambering process or reloading. At least your load wasn't high enough to stretch the brass by driving the head back against the bolt and thinning it above the web. You can get some measurements and contact your smith, do as others suggest and back off your load and jam the bullet into the lands (the easiest), or neck up a size and neck size back down to create a false shoulder with the correct headspace. You have options. Its a great cartridge. I'm loving mine.
 

can1010

Well-Known Member
Joined
Feb 27, 2012
Messages
1,161
A+ on what Tiny Tim said and don't bump the shoulders on the cases you already fired because they are not fully formed, if you do it will start the case head separation problem.
my preferred method is the false shoulder method. it seems to be the most reliable for proper case forming
 

Tiny Tim

Well-Known Member
Joined
Jan 26, 2015
Messages
905
A+ on what Tiny Tim said and don't bump the shoulders on the cases you already fired because they are not fully formed, if you do it will start the case head separation problem.
my preferred method is the false shoulder method. it seems to be the most reliable for proper case forming
I agree, the false shoulder method I'd best and after working the brass and fire forming twice, he should probably annealing as well.
 

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