[xdevildog]

Have a customer who brought in a Remington 700 that another smith had re-chambered from .25-06 to .25-06 Ackley Improved. He couldn't come up with a load that shot well, all of his fire formed cases where rounded at the shoulder - much like a Weatherby Mag. - rather than a sharp break, and he had experienced a case head separation I checked headspace and it was too long by about four thousandths using the scotch tape on the base of the no go gauge method of measuring.

Gave the barrel a full turn, set back the barrel tenon and bolt head recess, and turned a new chamber to spec. He called me the day after he picked up the rifle and was thrilled that it was cutting a single hole with five rounds at 100 yards. End of story, I thought. That was two weeks ago.

He called me today and said that he had fire formed 30 new brass. 27 had come out exactly as planned, but the last three had rounded shoulders and of those three the last one had a rounded shoulder and a rounded depression in one side about the size of the end of his little finger. I had him check case wall thickness at the necks of several of the good brass and of the malformed ones. No significant difference. He then weighed all the good brass and divided by 27 to get an average weight. Then he weighed the bad brass individually and found that all were one to four tenths of a grain heavier than the average.

I reload .38 Special, .45ACP, .308 and .30-06. Load them all milspec with FMJ projectiles and have never experienced anything like what he is going through. I suspect that the very steep shoulder angle of the Ackley Improved is at least part of the problem, but not sure. Anyway, here is the load and components he is using to fire form. Any thoughts would be very much appreciated.

New Hornady brass (in standard .25-06)
75 gr Hornady VMAX projectiles
50 gr of Reloader 15 powder
CCI 200 primers
3.235" OACL (he is seating to the lands for additional pressure)

:help:

 

[rugman59]

The last three rounds?? Sounds like the chamber got dirty and let some gas escape over the outside of the case. Did the fellow mention any uneven soot smears on the cases?

 

[xdevildog]

There was some soot staining on the casing with the indentation. He is emailing pix to me. Will post them here.

 

[xdevildog]

Here is a pix of one of the correctly fire formed brass, one of the brass with rounded shoulders, and the one brass with both rounded shoulders and a depression.

 

[steamer]

1. anything in chamber? is it clean?
2. Is he sure he set up loads exactly the same as the good formed one?
3. Does the brass thickness vary? are they all the same brand?
4. Did he anneal the brass after the primary forming?

I'm asking because I don't know the answers, not to be smart a$$

I form 17 Ackley Bee's and have to form the shoulder by fire forming.

Steamer

 

[xdevildog]

1. No. Yes, he cleaned the chamber and bore after the first rounded shoulder casing and got two more after that, including the one with the depression.
2. As sure as any of us are when measuring each load with an electronic scale.
3. Yes. He measured wall thickness of all thirty casings at the case neck and all were within 0.001". All brass was new, unfired Hornady.
4. No, but all the brass has only been loaded once to fire form. It has not been used since forming.

 

[SlugCatcher]

#4 looks like the norm for excessive lube during sizing.




he may want to back up just a little when engaging the lands. extra pressure can do all sorts of things that will leave you scratching your head.

 

[xdevildog]

#4 looks like the norm for excessive lube during sizing.
he may want to back up just a little when engaging the lands. extra pressure can do all sorts of things that will leave you scratching your head.

I've read that heavy machine guns in the WWI era that required lubricated cartridges to function produced similar spent brass, but had never seen it in person before.

 

[steamer]

So he formed the brass from another cartridge and then fire formed to the chamber?
If so that would harden the brass so you might have an issue. When you move it around by forming it does tend to harden up the brass.

I would try annealing the brass and then fire form some.
This is interesting...
Steamer

 

[rugman59]

So he formed the brass from another cartridge and then fire formed to the chamber?
If so that would harden the brass so you might have an issue. When you move it around by forming it does tend to harden up the brass.

I would try annealing the brass and then fire form some.
This is interesting...
Steamer

The brass was new. The Ackley Improved is basically taking an existing caliber with a tapered rifle case and fire forming it to a chamber that has had most of the taper removed, leaving a nearly straight walled case, thus greatly increasing powder capacity. No die forming is involved that I'm aware of.

That's a bit of a head scratcher with those last three rounds. SOMETHING had to change for three in a row after all the other successes. I'd be inclined to think the bullets were not seated as deeply. Did he use a light, heavy-- no crimp?
He didn't get lazy and have them in the magazine, did he?? (chuckle) Kidding.

 

[steamer]

I use cream of wheat to fire form...

Not to say I haven't loaded dented shells and blown them out with a bullet in the shell. lol

I agree, some thing we don't know about changed from the well formed one then 3 bad ones.

Steamer