12-gauge AA hulls collapsing on final crimp / resize station

[IMtheNRA]

I just started to reload 12-ga ammo. I'm using a recipe from Lyman #2 manual, with a Remington Power Piston wad (RXP-12) and 1 1/8 oz lead shot. The 1 1/8 bushing throws 495 grains of shot, rather than the expected 492.2 grains, but I don't think that's enough to cause my collapsing problem. I am using a Pacific DL-105 press.

About 1 in 10 loads, I'm getting these collapsed shells. The problem seems to occur mostly with the newer, smooth, "soft-feeling" plastic AA hulls. The old used, 80's vintage hulls that came with the press don't seem to collapse.

I noticed that all of my reloads, regardless of the hull's age, are slightly longer than the brand new factory AA shells that I compared them to. I assume they're longer because they got stretched during firing and the first decap/partial resize die. If so, I don't think there is anything I can do about this slight variance in length. Besides, the older hulls don't collapse, even though they are also a little longer than factory fresh AAs.

I'm wondering what causes hulls to collapse and whether I should move the final crimp/full length resize die up. The manual's troubleshooting section is silent on this issue.

 

[hartcreek]

I have had that happen too. Think about what you are actually doing when loading shot shells. It is no different then ant other shell. When you do not have a full powder charge and you force a crimp this happens. Your hull is not sitting on top of your powder. There is a void. When you press down on the crimp to hard and have a void this is what happens.

I use a Lee Load All A Lee load All has a crimp starter. On hulls that I know are going to be stubborn I use the starter twice and gently but firmly crimp. Sometime I have to rotate the shell and try the final crimp again. Old school shot shell loading tools had a kinda rotary tool crimp starter.

 

[35 Whelen]

Your final crimp die is misadjusted. I can see from the picture that first, the crimp itself is not deep enough and second that the die body, which creates the roll, or chamfer around the end of the hull, is set too low, which crushes the hull. If you're using anything but a Lee press, you're in good shape because the die can easily be adjusted.

Also it sounds like you're using two different hulls, the old original AA, and the new AA that is stamped "HS" (if memory serves). They are indeed two different hulls with two different sets of loading data....or at least they did when the newer hulls came out.

Anyhow, bottom lines is you need to adjust your final crimp die. What brand press are you using?

35W

 

[RugerBob]

He has a DL-105 press. I have the DL250 myself.
It could be the newer 'HS' hulls need to be seperated from the older ones.
The only time I had this issue was when I first got the press and had to back the crimp die out about 3/4 of a turn.
Try using wads for the AA brand and not remington.
Consistent pressure when seating wad.

 

[rg1]

Does look like your final crimp die is set too low? Another problem with the new HS Win hull is the two piece bottom. The lips of the wad hang on the top of the bottom base right about where you're getting collapse. I think the Remington wad would make it worse than using a softer Winchester wad in the 2 piece HS hull.

 

[oneounceload]

The newer AA hulls have a different design inside than the older ones and yes they are a touch shorter. Adjust your precrimp so that you have a very small opening and then adjust your final crimp upwards a touch so that it doesn't crush your hulls. You might also want to consider using one of the clones from Claybuster or Downrange - HALF the price of Remington wads

Once I lowered my shot load, any of those issues seemed to go away. I now reload a 3/4oz 12 gauge load - easy on both the wallet and the shoulder

 

[IMtheNRA]

Based on these replies, I'm going to take two steps:


1. Precrimp: I am going to lower the pre-crimp die until the hole left in the "dome" is about the size of a piece of shot.

2. Final crimp+full length resize die: There are two adjustments available on the last die - the crimp, which is adjusted with the screw on top of the die, or the entire die, which could be screwed further up into the press head. Which of these two options do you recommend that I adjust on this particular die?

 

[oneounceload]

It is easier to work your way down with the crimp so back it out and start to lower it enough until you get the crimp you want without the buckling

 

[IMtheNRA]

So you're saying that I should back out the crimp control screw, but not raise the entire die in that final station?

 

[35 Whelen]

My method is the set the crimp depth, with the crimp control screw first, somehow mark the position of the screw, back it out, then using the same shell, adjust the die body. After this is correct, return the crimp screw to its proper depth.

Have you looked at the loader manual? They usually tell you how to do this.

35W

 

[gamestalker]

Check to be sure you are applying enough start crimp, then adjust the final crimp up. Actually, what I would do is adjust the final crimp up far enough that it isn't producing a complete crimp, then start adjusting it back down until you are getting a normal recessed crimp.

Also, make sure your getting enough wad pressure to completely seat the wad down against the powder charge. Also make sure the wad is going in straight.

Double check that you have the correct crimp, either a 6 point, or 8 point, depending on the hull, which AA's are an 8 point. The wrong crimp can cause this type of issue also.

I didn't research your load and components, but make sure that your are using matched load components, as it is published, including the powder. mis matched shot shell recipe's can produce problems like this, and it can get far more serious.

GS

 

[oneounceload]

I swap components all the time, and they are still OK - most can be done safely. But as others have mentioned - back it out, start lowering it down until it works

 

[John3921]

The AAHS hull is weak and short. Hull buckling is usually too much stuff inside the hull. Your crimp depth should be about 0.055, about the thickness of a dime. You may need to find a slightly shorter wad to eliminate hull buckling.

The HS hull has a separate base wad. The wads for the HS hulls should have a very slight bevel on the powder skirt so as not to hang up on the base wad.

The Downrange XL 12 1-1/8 th oz. wads for the HS hull seem to get about the best reviews for fit in the AAHS hulls.

 

[IMtheNRA]

Hi, thanks a lot to everyone for the helpful suggestions. I tried them all and the one that had the most positive effect was to seat the wad deeper. I unscrewed the wad seating rod one full turn, which added about 2mm to its downstroke.

This made a bit more room for the shot and the hull crumpling stopped on all of the older red AAs and almost disappeared on the new gray AA hulls. I still slightly collapsed about 5 gray hulls out of 100, so I plan to add even more downstroke to wad seating when using gray hulls.