A I fireforming

[bandur60]

I'm new to this aspect of reloading, am working on forming 22-250 Rem (once fired in standard 22-250) to Ackley Improved. Today I ran through 40 rounds, 4 x 5 each of two different powders loaded in 22-250 R-P cases, CCI 200 primers. Out of the 40, eight did not fire. When I got home I pulled the bullets and dumped the powder, then out of curiousity ran them through the rifle again. Five went off, three did not.

Before loading I sized them through the A I die (only one I have) to get the necks sized down to hold the bullet, loaded and used a Lee crimp die to finish. My question: is this common in such a situation? I wondered if the original shoulders sometimes might not be held back in the A I chamber far enough, or firmly enough, to stand up to the firing pin strike because of the milder angle they have? The firing pin definitely struck them the first time. Any suggestions or comments?

I have all the brass I need and don't plan on using those eight cases again, but is this a common occurence in fireforming? Open to any ideas or education. Thanks

 

[Varminterror]

Sounds like you have your die set to size the cases too far, such your brass is undersized and not securely wedging into the neck.

If your brass is simply short at the shoulder, you do have the option to jam bullets or create a false shoulder to ensure the case heads are held pressed against the bolt face during firing. Just depends how far away your brass is right now from proper neck/shoulder junction to provide sufficient headspace.

 

[bandur60]

Should have done some reading earlier namely about "false shoulders". I took three of the cases and ran them over a .243 Win expander, only until it entered the case body, then through the 22-250 A I size die again. Is that a way of attacking the problem? I didn't really want to expand the necks too much but could next size up to a .257 (???). Thanks

I did size a few down from 250 Savage and had no problem with misfires. Today there were more than I've had since beginning handloading, circa 1972-3

 

[Varminterror]

I took three of the cases and ran them over a .243 Win expander, only until it entered the case body, then through the 22-250 A I size die again. Is that a way of attacking the problem?

Done properly, that’s how you make a false shoulder.

How are you setting your sizing die? If you expand with a 6mm expander, then your bolt should not close on the brass, then you should run the cases into the 22-250AI die, adjusting down from the top and set them JUST where the bolt closes, and no deeper. Even leaving a little crush fit for the case is a benefit.

 

[lightman]

The only AI that I have is also a 22-250 and I've had no problems. So I would say your problem is not common. I resize the case the first time in the standard die and I use a max charge for the parent case.

 

[41 Mag]

I have 223, 30-30, and 25-06 AI's, and have formed 100s of cased. The only time I've had a FTF is when I hadn't seated the primer properly. They usually did fire the second try.

Chambered properly any AI chamber should fit the parent case properly on the datum line of the shoulder and hold it in place properly. That's one of the things that make them versatile. You should be able to fire factory ammo through them and end up with usually decent accuracy and a fully formed case.

For handloaded fireformed cases I've always chosen a load that uses one of the mid burn rate powders and loaded to a grain or so under the max listed load, or if there was a factory equivalent load I used that. Most times these loads were also easily good enough for hunting purposes.

You should not have to worry about a false shoulder unless you are forming a case for something like the 7x30 Waters where you are going from one caliber to another. In that case then you want to set the new shoulder so you get a very slight crush fit to hold it in place during firing. Some recommend seating long so the bullet holds the case back but I've found that this can easily spike pressures to dangerous levels and ruin cases or worse.

 

[Varminterror]

Chambered properly any AI chamber should fit the parent case properly on the datum line of the shoulder and hold it in place properly.

When first fireforming to improve, the AI chamber doesn’t contact the “datum line” at all, as the chamber only makes contact at the very tip of the shoulder at the neck/shoulder junction. If a chamber is rather loose or cases slightly undersized, this contact is lost and the shoulder wedges slightly into the chamber neck, offering excessive headspace, hence leaving a slight false shoulder bulge at the base of the neck will offer the missing contact needed to keep the rounds pressed against the bolt face.

Far more common that misfires are poorly seated primers, but that’s a pretty easy diagnosis to scratch off of the list, so I take the OP’s issue as presented.

 

[bandur60]

Varminterror, your instruction in post #4 makes perfect sense to me and I'm out to work on some very soon. Expand the neck with .243, raise the .22 size die "a bit", try to chamber, and adjust size die down just until the case will chamber. I think I've got it.

This is why I love THR even though I don't post very often!!

 

[marchboom]

Maybe I'm missing something but why would you expand the neck to .243"? Rather drastic. You might want to have the chamber checked to see if the chambering was done properly. Some gunsmiths aren't that good when chambering to an Ackley Improved. I never had any problems fireforming 22-250 brass to an AI.

Please let us know when you discover the problem.