Bullet Seating Problem

Have you analyzed a piece of brass from that particular lot? When the settings and pilot are correct I've never seen an AMP over-heat brass. Of any make.

Sacrifice one piece and be sure, for certainty.

I don't believe anyone can over anneal brass, at least not with any of the common methods handloaders use. Its possible one can be inconsistent in their annealing process and maybe thats contributing to the problems but annealing brass is pretty basic, hard to mess that up.
Consistency is the key to accurate loads, so I anneal after each firing and have not had any issues with brass hardness.

Koda_ said:

I don't believe anyone can over anneal brass, at least not with any of the common methods handloaders use. Its possible one can be inconsistent in their annealing process and maybe thats contributing to the problems but annealing brass is pretty basic, hard to mess that up.
Consistency is the key to accurate loads, so I anneal after each firing and have not had any issues with brass hardness.

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There are only two ways to ruin brass, 1) is to overwork it until it becomes brittle and the molecular structure breaks down, the other way 2) is to overheat or over anneal the brass which also breaks down the molecular structure. Case brasses are different with different alloys depending on the maker. The better brass case by Norma or Lapua will withstand abuse, even Winchester brass is pretty good. With the shortage of the components used to make brass cases a lot of makers are cutting corners and using alloys that are not compatible with the abuse a cartridge case usually takes.

I think I know the problem. The neck tension is a bit too tight along with very soft brass from annealing. Combine that with the steep angle shoulder of the improved type 40 ish deg cartridge and the seating force is causing the shoulder to slightly collapse. This puts a taper on the case neck resulting in only the case mouth making good contact with the bearing surface. Then because of the drive band design you are moving the single point of contact between the drive bands. We fought this multiple times before figuring out what was going on. Our initial instinct was to increase neck tension or crimp to stop it. This just made it worse when using a taper crimp. Reducing neck tension eased the force to seat, eliminating the problem letting the entire neck to contact the drive bands.

Making sure there is a good chamfer in the case mouth will also help with the initial seating force to start the bullet into the case mouth.

Hope this helps.

Richard Kramer said:

There are only two ways to ruin brass, 1) is to overwork it until it becomes brittle and the molecular structure breaks down, the other way 2) is to overheat or over anneal the brass which also breaks down the molecular structure.

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Im still undecided on if it can be over annealed, at least with our processes. I havent read anything conclusive. I hear it can be over annealed but really just what would it take to do that I dont suspect any handloader lets it sit in the flame that long.

Eric Cortina actually tested this. He intentionally over annealed brass and then measured seating depth force with a pressure gaugue. His results were nothing changed all the samples averaged the same neck tension.
(queued up to the results if your short on time but its otherwise a good watch)

Koda_ said:

Im still undecided on if it can be over annealed, at least with our processes. I havent read anything conclusive. I hear it can be over annealed but really just what would it take to do that I dont suspect any handloader lets it sit in the flame that long.

Eric Cortina actually tested this. He intentionally over annealed brass and then measured seating depth force with a pressure gaugue. His results were nothing changed all the samples averaged the same neck tension.
(queued up to the results if your short on time but its otherwise a good watch)

Click to expand...

Yes, I've seen this, however Cortina also uses Lapua brass.

When I switched do ADG brass from Nosler in one of my 300 RUMs I didn't bother to "burn" a case to get the AMP code, figuring the Nosler setting would work. The first time I sized the neck with a mandrel die, it collapsed the neck. I then did what I should have done the first time and ran the analyze step - the code was a lot lower than the Nosler brass. No more collapsed shoulders.

FWIW, I anneal all of my LR loads every time I load, and aside from the above problem, I haven't had issues.

One more thought: did the OP neck turn too much? I did this once with one of 28Ns and had the same problem: bullets would move with finger pressure.

I didn't turn necks.
Appreciate all input. I suspect Steve is right about too much neck "tension" and soft brass. That fits with what I was seeing.
In future I plan to use .314 bushing and expect seated OD to be .317.

I agree with Phil Rizzo, double check your AMP code by analyzing another piece or two...

FWIW, I sacrificed/analysed another 28 Nos ADG case and got the same code as before, 150. So all the cases were annealed as per AMP rec's. In the future with loading these HHT 170's, I'm gonna use only 2-3 thousands seating tension and anneal infrequently.
Got a limited draw CO elk hunt in 2 months.