Fireforming AI brass ..... Jam or not?

Goin'Hot

Gunny Sergeant
Full Member
Minuteman
Nov 14, 2008
2,271
56
Central, Ohio
Getting a 223 reamed to AI and having a 243 AI built. How do you guys ensure good fire formed brass? Do you jam the bullet into the lands and reduce the powder charge? Or do you start with "mag length" and run close to max charge?
 
Re: Fireforming AI brass ..... Jam or not?

Yes, I tend to put the bullet into the lands by 0.02". This makes for almost perfect 260 AI brass from 260 Remington cases.
 
Re: Fireforming AI brass ..... Jam or not?

Not exactly AI, but for the 6mm Crusader, the following worked best:

-Jam 0.020" into the lands
-Lube cases lightly
-Used MAX charged for parent cartridge

Loads below MAX left some corners rounded.
 
Re: Fireforming AI brass ..... Jam or not?

I used factory Black Hills 60gr for my 223ai, and it fireformed just fine. I also loaded amaxes to jam, and they fireformed fine...couldn't tell a difference between the two. That's the beauty of it: Insert round, pull trigger, extract fireformed brass.
 
Re: Fireforming AI brass ..... Jam or not?

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: 308sako</div><div class="ubbcode-body">Jam and now also putting some <span style="text-decoration: underline">Imperial</span> on the forward portion of the case, forms more concentric. .243 AI, 257 AI, 30-06 AI </div></div>

What is this Imperial you refer to?
 
Re: Fireforming AI brass ..... Jam or not?

Depends on the smith and reamers used. They are supposed to headspace on the junction of the neck and shoulder...which is supposed to be the identical length.If they are not...due to different reamers or the smith cutting just a bit deeper, then you will have excess headspace and while probably not dangerous, can stretch the brass the first time it is fired reducing case life. Jamming it will ensure the shoulder moves forward establishing the proper headspace in YOUR rifle. JMHO
 
Re: Fireforming AI brass ..... Jam or not?

I had a 260 AI built about 4 years ago and have been using federal premium factory loads to make brass. Not cheap but works great and in the 260's case, I have had the best luck with the fed brass. These fireformed cases are as close to perfect as I can tell. Shoots good while forming too.